Nanoparticles for extended release drug delivery

Abstract

The present invention is directed to peptide modified polymers, nanoparticle compositions comprising peptide modified polymers, nanoparticle compositions comprising a polynucleotide in addition to peptide modified polymers, methods for preparing said peptide modified polymers and nanoparticle compositions, and uses thereof. The polymers can in particular be poly(beta-aminoesters).

Description

[0001] NANOPARTICLES FOR EXTENDED RELEASE DRUG DELIVERY FIELD OF THE INVENTION The present invention relates generally to the field of polymers, nanoparticle compositions, and transfection. In particular, the invention is directed to peptide modified polymers, nanoparticle compositions comprising peptide modified polymers, nanoparticle compositions comprising a polynucleotide in addition to peptide modified polymers, methods for preparing said peptide modified polymers and nanoparticle compositions, and uses thereof. BACKGROUND OF THE INVENTION The number of nucleic acid therapies (NATs) gaining regulatory approval has steadily increased over the last two decades. This has been accompanied by an increasing need for effective delivery systems. In particular, nucleic acid-based modalities, encompassing both DNA / RNA, continue to advance novel treatment interventions for infectious diseases, genetic disorders and malignancies. mRNA-based therapies have emerged as highly desired platform technologies due to mRNA conferring reduced immunogenicity, and the ability to transfect quiescent, slow-proliferative or differentiated cell populations. Additionally, although targets such as the epithelial layer, e.g. lung epithelial cells, remain highly desirable for advanced therapeutics such as nucleic acid therapies, the epithelial layer is difficult to transfect using conventional transfection agents. Transfecting human airway epithelium cells remains challenging due to the complex interplay between cell status in differentiation and proliferation (division), barrier function and mucosal clearance hampering transfection. Slow proliferative and / or terminally differentiated cells such as lung epithelial cells often have low transfection efficiency due to limiting numbers of target cells, diminished receptivity to foreign nucleic acid cellular uptake, lacking inclination to divide and increased levels of cellular stress induced by foreign nucleic acids. These difficulties significantly limit the treatment options available for e.g. lung diseases and disorders. There is therefore a need for agents which enable the transfection of epithelial cells. There is also a need for formulations comprising such agents to be stable as aerosol or spray e.g. nasal spray formulations, so that they may conveniently be used in these applications. The majority of approved NATs are formulated in lipid nanoparticles that comprise of an ionisable lipid for electrostatic complexation with negatively charged nucleic acid, and helper lipids that promote fusion with the cell membrane. See e.g. Schoenmaker, L. et. al., Int. J. Pharm., 2021, 601, 120586. However, limitations include immunogenicity, instability, liver accumulation, and reduced capacity of lipids for larger cargo such as saRNA has hindered progress of NATs. In response to these challenges, polymeric nanomaterials have demonstrated versatile nucleic acid delivery and a large chemical space for diverse modification, however they have low transfection efficiency particularly for terminally differentiated or slowly dividing cell populations which remain difficult to transfect. There is a strong need for more sophisticated nucleic acid delivery systems that have specific bioactivity for cellular interaction and tuneable physical properties for enhanced stability. There is therefore a real need in the art to develop agents such as polymers, modified polymers, and nanoparticles for polynucleotide delivery. Further, there is a need for such agents to be stable in aqueous and protein rich biological media, have high encapsulation efficiencies and possess an excellent cytotoxicity profile. Further, the methods for producing these agents for transfection should ideally be amenable to fine tuning, in order to optimise the structure / hydrophobicity / size of the agents e.g. nanoparticles for a particular polynucleotide and / or application. It would also be advantageous if such agents were biodegradable such that they degrade under physiological conditions. SUMMARY OF THE INVENTION The present disclosure includes, among other aspects and embodiments, the following aspects and embodiments which are presented as numbered clauses 1 to 251: 1. A peptide modified polymer for nucleic acid delivery comprising: a radical of Formula (A) having the structure: a diradical of Formula (B) having the structure: a diradical of Formula (C) having the structure: wherein: each radical of Formula (A) has one point of attachment to a diradical of Formula (B); each diradical of Formula (B) has two points of attachment to separate radicals independently selected from: Formula (A) and Formula (C); each diradical of Formula (C) has two points of attachment, each to a separate diradical of Formula (B); wherein each X is independently selected from: -O-, -S-, and -NRw-; wherein each Y is independently selected from: =O, =S, and -OH; wherein L1is a hydrocarbyl linker comprising 1 to 500 carbon atoms; wherein R1is a peptide radical; wherein each R2is independently selected from: -H, -C1to C20alkyl; -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, and -C2to C20alkynyl; wherein said -C1to C20alkyl; -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, or -C2to C20alkynyl group is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -OR4, -NH2, -NHR4, -NR42, -C(O)OH, -C(O)OR4, -C(O)NH2, -C(O)NHR4, -C(O)NR42, - O(CO)H, -O(CO)R4, -NH(CO)H, -NH(CO)R4, -NR4(CO)H, -NR4(CO)R4, -SH, -SR4, -SO2H, -SO2R4, -SO3R4, -SO3H, -SiR43, -NO2, -CN, -F, -Cl, -Br, -I, -C6to C14aryl optionally substituted with one or more R5groups, and -C2to C9heteroaryl optionally substituted with one or more R5groups; wherein each R3is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyloxy, -C1to C20alkylamino, -C6to C14aryl optionally substituted with one or more R6groups, and -C2to C9heteroaryl optionally substituted with one or more R6groups; wherein said -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyloxy, or -C1to C20alkylamino group is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl-C3to C20cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C1to C20alkyloxy, -C1to C20alkylamino, -OH, -OR7, -NH2, -NHR7, - NR72, -C(O)OH, -C(O)OR7, -C(O)NH2, -C(O)NHR7, -C(O)NR72, -O(CO)H, -O(CO)R7, - NH(CO)H, -NH(CO)R7, -NR7(CO)H, -NR7(CO)R7, -SH, -SR7, -SO2H, -SO2R7, -SO3R7, - SO3H, -SiR73, -NO2, -CN, -F, -Cl, -Br, -I, -C6to C14aryl optionally substituted with one or more R8groups, and -C2 to C9 heteroaryl optionally substituted with one or more R8groups; wherein each R4is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl- C3to C10cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C1to C20alkoxy, -C1to C20 alkylamino, -C6 to C14 aryl, and -C2 to C9 heteroaryl; wherein each R5is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I; wherein each R6is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I; wherein each R7is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl- C3to C10cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C1to C20alkoxy, -C1to C20alkylamino, -C6to C14aryl, and -C2to C9heteroaryl; wherein each R8is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I; and wherein each Rwis independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, and -C2to C20alkenyl. 2. The peptide modified polymer for nucleic acid delivery according to clause 1 or clause 213 additionally comprising: a radical species of Formula (D) having the structure: wherein: each radical species of Formula (D) has at least two points of attachment to separate diradicals of Formula (B) and each * independently denotes a point of attachment to (i) a separate diradical of Formula (B), or (ii) a substituent R9; wherein L2is a hydrocarbyl linker comprising 1 to 500 carbon atoms; wherein each R9is independently selected from: -H, -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, and -C2to C20 alkynyl, wherein said -C1 to C20 alkyl, -C1 to C20 haloalkyl, -C3 to C20 cycloalkyl, -C3 to C20heterocycloalkyl, -C2to C20alkenyl, or -C2to C20alkynyl is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, - OR10, -NH2, -NHR10, -NR102, -C(O)OR10, -C(O)NH2, -C(O)NHR10, -C(O)NR102, -O(CO)H, - O(CO)R10, -NH(CO)H, -NH(CO)R10, -NR10(CO)H, -NR10(CO)R10, -SR10, -NO2, -CN, -F, - Cl, -Br, -I, -C6 to C14 aryl optionally substituted with one or more R11groups, and -C2 to C9 heteroaryl optionally substituted with one or more R11groups; wherein each R10is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl- C3to C10cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C1to C20alkoxy, -C1to C20alkylamino, -C6to C14aryl, and -C2to C9heteroaryl; and wherein each R11is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I. 3. The peptide modified polymer according to clause 1 or clause 2 or clause 213 wherein each X is independently selected from: -O-, -S-, and -NRw-. 4. The peptide modified polymer according to any one of clauses 1-3 or clause 213 wherein each X is -NRw-. 5. The peptide modified polymer according to any one of clauses 1-4 or clause 213 wherein each Rwis independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, and -C2to C20alkenyl. 6. The peptide modified polymer according to any one of clauses 1-5 or clause 213 wherein each Rwis independently selected from: -C1to C20alkyl and -C3to C20cycloalkyl. 7. The peptide modified polymer according to any one of clauses 1-6 or clause 213 wherein each Rwis independently selected from: -C1to C8alkyl and -C3to C8cycloalkyl. 8. The peptide modified polymer according to any one of clauses 1-7 or clause 213 wherein each Rwis independently selected from: -C1to C8alkyl. 9. The peptide modified polymer according to any one of clauses 1-3 or clause 213 wherein each X is -S-. 10. The peptide modified polymer according to any one of clauses 1-3 or clause 213 wherein each X is -O-. 11. The peptide modified polymer according to any one of clauses 1-10 or clause 213 wherein each Y is independently selected from: =O, =S, and -OH. 12. The peptide modified polymer according to any one of clauses 1-11 or clause 213 wherein each Y is =S. 13. The peptide modified polymer according to any one of clauses 1-11 or clause 213 wherein each Y is =O. 14. The peptide modified polymer according to any one of clauses 1-11 or clause 213 wherein each Y is -OH. 16. The peptide modified polymer according to any one of clauses 1-3, 9, 11, 12, and 213 wherein each X is -S-, and each Y is =S. 15. The peptide modified polymer according to any one of clauses 1-3, 9, 11, 13, and 213 wherein each X is -S-, and each Y is =O. 17. The peptide modified polymer according to any one of clauses 1-3, 9, 11, 14, and 213 wherein each X is -S-, and each Y is -OH. 18. The peptide modified polymer according to any one of clauses 1-8, 11, 13, and 213 wherein each X is -NRw-, and each Y is =O. 19. The peptide modified polymer according to any one of clauses 1-8, 11, 12, and 213 wherein each X is -NRw-, and each Y is =S. 20. The peptide modified polymer according to any one of clauses 1-8, 11, 14, and 213 wherein each X is -NRw-, and each Y is -OH. 21. The peptide modified polymer according to any one of clauses 1-3, 10, 11, 13, and 213 wherein each X is -O-, and each Y is =O. 22. The peptide modified polymer according to any one of clauses 1-3, 10, 11, 12, and 213, wherein each X is -O-, and each Y is =S. 23. The peptide modified polymer according to any one of clauses 1-3, 10, 11, 14, and 213, wherein each X is -O-, and each Y is -OH. 24. The peptide modified polymer according to any one of clauses 1-3, 10, 11, 13, 21, and 213, wherein the diradical of Formula (B) is defined by Formula (B-I): wherein each R2and L1are as defined herein. 25. The peptide modified polymer according to any one of clauses 1-24 and 213, wherein each R2is independently selected from: -H, -C1to C20alkyl; -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, and -C2to C20alkynyl; wherein said -C1to C20alkyl; -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20 heterocycloalkyl, -C2 to C20 alkenyl, or -C2 to C20 alkynyl group is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -OR4, -NH2, -NHR4, -NR42, -C(O)OH, -C(O)OR4, -C(O)NH2, -C(O)NHR4, -C(O)NR42, - O(CO)H, -O(CO)R4, -NH(CO)H, -NH(CO)R4, -NR4(CO)H, -NR4(CO)R4, -SH, -SR4, -SO2H, -SO2R4, -SO3R4, -SO3H, -SiR43, -NO2, -CN, -F, -Cl, -Br, -I, -C6to C14aryl optionally substituted with one or more R5groups, and -C2 to C9 heteroaryl optionally substituted with one or more R5groups. 26. The peptide modified polymer according to any one of clauses 1-25 and 213, wherein each R2is independently selected from: -H, -C1to C20alkyl; -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, and -C2to C20alkynyl; wherein said -C1to C20alkyl; -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, or -C2to C20alkynyl group is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -OR4, -NH2, -NHR4, -NR42, -C(O)OR4, -C(O)NH2, - C(O)NHR4, -C(O)NR42, -O(CO)R4, -NH(CO)R4, -NR4(CO)R4, -SH, -SR4, -SO2R4, -SO3R4, -SiR43, -NO2, -CN, -F, -Cl, -Br, -I, -C6to C14aryl optionally substituted with one or more R5groups, and -C2to C9heteroaryl optionally substituted with one or more R5groups. 27. The peptide modified polymer according to any one of clauses 1-26 and 213, wherein each R2is independently selected from: -H, -C1to C20alkyl; -C1to C20haloalkyl, and -C2to C20alkenyl; wherein said -C1to C20alkyl; -C1to C20haloalkyl, or -C2to C20alkenyl is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -OH, -OR4, -NH2, -NHR4, -NR42, -C(O)OR4, -C(O)NH2, -C(O)NHR4, - C(O)NR42, -O(CO)R4, -NH(CO)R4, -NR4(CO)R4, -SH, -SR4, -NO2, -CN, -F, -Cl, -Br, -I, -C6to C14aryl optionally substituted with one or more R5groups, and -C2to C9heteroaryl optionally substituted with one or more R5groups. 28. The peptide modified polymer according to any one of clauses 1-27 and 213, wherein each R2is independently selected from: -H, -C1to C20alkyl; -C1to C20haloalkyl, and -C2to C20alkenyl; wherein said -C1to C20alkyl; -C1to C20haloalkyl, or -C2to C20alkenyl is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C2to C20alkenyl, -OH, -OR4, -NH2, -NHR4, -NR42, -C(O)OR4, -C(O)NH2, - C(O)NHR4, -C(O)NR42, -O(CO)R4, -NH(CO)R4, -NR4(CO)R4, -SH, -C6to C14aryl optionally substituted with one or more R5groups, and -C2to C9heteroaryl optionally substituted with one or more R5groups. 29. The peptide modified polymer according to any one of clauses 1-28 and 213, wherein each R2is independently selected from: -H and -C1to C20alkyl; wherein said -C1to C20alkyl is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C2to C20alkenyl, -OH, -OR4, -NH2, -NHR4, -NR42, -C(O)OR4, -C(O)NH2, -C(O)NHR4, -C(O)NR42, -O(CO)R4, -NH(CO)R4, -NR4(CO)R4, -SH, -C6to C14aryl optionally substituted with one or more R5groups, and -C2to C9heteroaryl optionally substituted with one or more R5groups. 30. The peptide modified polymer according to any one of clauses 1-29 and 213, wherein each R2is independently selected from: -H and -C1to C20alkyl; wherein said -C1to C20alkyl is optionally substituted with one or more group independently selected from: -C1to C8alkyl, -C2to C8alkenyl, -OR4, -NR42, -C(O)OR4, -C(O)NR42, -O(CO)R4, - NH(CO)R4, -NR4(CO)R4, -C6to C14aryl optionally substituted with one or more R5groups, and -C2to C9heteroaryl optionally substituted with one or more R5groups. 31. The peptide modified polymer according to any one of clauses 1-30 and 213, wherein each R2is independently selected from: -H and -C1to C8alkyl; wherein said -C1to C8alkyl is optionally substituted with one or more group independently selected from: - C1to C8alkyl, -C2to C8alkenyl, -OR4, -NR42, -C(O)OR4, -C(O)NR42, -O(CO)R4, - NH(CO)R4, -NR4(CO)R4, -C6to C14aryl optionally substituted with one or more R5groups, and -C2to C9heteroaryl optionally substituted with one or more R5groups. 32. The peptide modified polymer according to any one of clauses 1-31 and 213, wherein each R2is independently selected from: -H and -C1to C8alkyl; wherein said -C1to C8alkyl is optionally substituted with one or more group independently selected from: - C1to C8alkyl, -C2to C8alkenyl, -OR4, -NR42, -C(O)OR4, -C(O)NR42, -O(CO)R4, - NH(CO)R4, and -NR4(CO)R4. 33. The peptide modified polymer according to any one of clauses 1-32 and 213, wherein each R2is independently selected from: -H and -C1to C20alkyl. 34. The peptide modified polymer according to any one of clauses 1-33 and 213, wherein each R2is independently selected from: -H and -C1to C8alkyl. 35. The peptide modified polymer according to any one of clauses 1-34 and 213, wherein each R2is independently selected from -C1to C8alkyl. 36. The peptide modified polymer according to any one of clauses 1-35 and 213, wherein each R2is -H. 37. The peptide modified polymer according to any one of clauses 1-36 and 213 wherein each R4is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20 alkyl-C6 to C14 aryl, -C1 to C20 alkyl-C2 to C9 heteroaryl, -C1 to C20 alkyl-C3 to C10 cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C1to C20alkoxy, -C1to C20alkylamino, -C6to C14aryl, and -C2to C9heteroaryl. 38. The peptide modified polymer according to any one of clauses 1-37 and 213 wherein each R4is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C1to C20alkyl-C6to C14aryl, -C1 to C20 alkyl-C2 to C9 heteroaryl, -C1 to C20 alkyl-C3 to C10 cycloalkyl, -C1 to C20 alkyl-C3to C10heterocycloalkyl, -C6to C14aryl, and -C2to C9heteroaryl. 39. The peptide modified polymer according to any one of clauses 1-38 and 213 wherein each R4is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C6to C14aryl, and -C2to C9heteroaryl. 40. The peptide modified polymer according to any one of clauses 1-39 and 213 wherein each R4is independently selected from: -C1to C20alkyl, C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C6to C14aryl, and -C2to C9heteroaryl. 41. The peptide modified polymer according to any one of clauses 1-40 and 213 wherein each R4is independently selected from: -C1to C20alkyl and -C2to C20alkenyl. 42. The peptide modified polymer according to any one of clauses 1-41 and 213 wherein each R4is independently selected from -C1to C20alkyl. 43. The peptide modified polymer according to any one of clauses 1-42 and 213 wherein each R4is independently selected from -C1to C8alkyl. 44. The peptide modified polymer according to any one of clauses 1-43 and 213 wherein each R5is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I. 45. The peptide modified polymer according to any one of clauses 1-44 and 213 wherein each R5is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -F, - Cl, -Br, and -I. 46. The peptide modified polymer according to any one of clauses 1-45 and 213 wherein each R5is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -OH, -NH2, -OC1to C20alkyl, -F, -Cl, -Br, and -I. 47. The peptide modified polymer according to any one of clauses 1-46 and 213 wherein each R5is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -OC1to C20alkyl, -F, -Cl, -Br, and -I. 48. The peptide modified polymer according to any one of clauses 1-47 and 213 wherein each R5is independently selected from: -C1to C20alkyl, -C3to C20cycloalkyl, - OC1to C20alkyl, -F, -Cl, -Br, and -I. 49. The peptide modified polymer according to any one of clauses 1-48 and 213 wherein each R5is independently selected from: -C1to C8alkyl, -C3to C8cycloalkyl, -OC1to C8alkyl, -F, -Cl, -Br, and -I. 50. The peptide modified polymer according to any one of clauses 1-49 and 213 wherein each R5is independently selected from: -C1to C8alkyl, -C3to C8cycloalkyl, -OC1to C8alkyl, -F, -Cl, -Br, and -I. 51. The peptide modified polymer according to any one of clauses 1-50 and 213 wherein each R5is independently selected from -C1to C8alkyl. 52. The peptide modified polymer according to any one of clauses 1-51 and 213 wherein L1is selected from: optionally substituted aliphatic (e.g. alkylene, alkenylene, or alkynylene), optionally substituted heteroaliphatic (e.g. heteroalkylene), optionally substituted carbocyclylene, optionally substituted heterocyclylene, optionally substituted arylene, optionally substituted heteroarylene, and a combination thereof. 53. The peptide modified polymer according to any one of clauses 1-52 and 213 wherein L1is selected from: substituted aliphatic, unsubstituted aliphatic, substituted heteroaliphatic, unsubstituted heteroaliphatic, substituted arylene, unsubstituted arylene, substituted heteroarylene, unsubstituted heteroarylene, and a combination thereof. 54. The peptide modified polymer according to any one of clauses 1-53 and 213 wherein L1is optionally substituted aliphatic (e.g. alkylene, alkenylene, or alkynylene). 55. The peptide modified polymer according to any one of clauses 1-54 and 213 wherein L1is optionally substituted alkylene. 56. The peptide modified polymer according to any one of clauses 1-55 and 213 wherein L1is alkylene. 57. The peptide modified polymer according to any one of clauses 1-56 and 213 wherein L1is –(CH2)m- wherein m is from 1 to 500, 1 to 400, 1 to 300, 1 to 200, 1 to 190, 1 to 180, 1 to 170, 1 to 160, 1 to 150, 1 to 140, 1 to 130, 1 to 120, 1 to 110, 1 to 100, 1 to 95, 1 to 90, 1 to 85, 1 to 80, 1 to 75, 1 to 70, 1 to 65, 1 to 60, 1 to 55, 1 to 50, 1 to 45, 1 to 40, 1 to 35, 1 to 30, 1 to 25, 1 to 20, 1 to 15, 1 to 10, or 1 to 5. 58. The peptide modified polymer according to any one of clauses 1-57 and 213 wherein L1is selected from: , , and . 59. The peptide modified polymer according to any one of clauses 1-51 and 213 wherein 60. The peptide modified polymer according to any one of clauses 1-59 and 213 wherein is selected from: , , wherein each R2is -H. 61. The peptide modified polymer according to any one of clauses 1-53 and 213 wherein L1is a hydrophilic linker, e.g. a heteroalkylene or a PEG linker. 62. The peptide modified polymer according to any one of clauses 1-53, 61, and 213 wherein L1is optionally substituted heteroalkylene. 63. The peptide modified polymer according to any one of clauses 1-53, 61, 62, and 213 wherein L1is heteroalkylene. 64. The peptide modified polymer according to any one of clauses 1-53, 61-63, and 213 wherein L1is heteroalkylene and R2is H. 65. The peptide modified polymer according to any one of clauses 1-53, 61-64, and 213 wherein L1is heteroalkylene wherein the carbon chain length is from 1 to 500, 1 to 400, 1 to 300, 1 to 200, 1 to 190, 1 to 180, 1 to 170, 1 to 160, 1 to 150, 1 to 140, 1 to 130, 1 to 120, 1 to 110, 1 to 100, 1 to 95, 1 to 90, 1 to 85, 1 to 80, 1 to 75, 1 to 70, 1 to 65, 1 to 60, 1 to 55, 1 to 50, 1 to 45, 1 to 40, 1 to 35, 1 to 30, 1 to 25, 1 to 20, 1 to 15, 1 to 10, or 1 to 5 carbon atoms. 66. The peptide modified polymer according to any one of clauses 1-53, 61-65, and 213 wherein L1is ; wherein n is an integer selected from 0 to 250, for example n is 0 or 2. 67. The peptide modified polymer according to clause 66 wherein n is an integer selected from 0 to 250, 0 to 225, 0 to 200, 0 to 190, 0 to 180, 0 to 170, 0 to 160, 0 to 150, 0 to 140, 0 to 130, 0 to 120, 0 to 110, 0 to 100, 0 to 95, 0 to 90, 0 to 85, 0 to 80, 0 to 75, 0 to 70, 0 to 65, 0 to 60, 0 to 55, 0 to 50, 0 to 45, 0 to 40, 0 to 35, 0 to 30, 0 to 25, 0 to 20, 0 to 15, 0 to 10, or 0 to 5. 68. The peptide modified polymer according to clause 66 or 67 wherein n is selected from 0, 2, and 13. 69. The peptide modified polymer according to any one of clauses 1-53, 61-68, and 213 wherein 70. The peptide modified polymer according to any one of clauses 1-69 and 213 wherein the number average molecular weight (Mn) of L1is about 5000, about 4000, about 3000, about 2000, about 1000, about 950, about 900, about 850, about 800, about 750, about 700, about 650, about 600, about 550, about 500, about 450, about 400, about 350, about 300, about 250, or about 200. 71. The peptide modified polymer according to any one of clauses 1-70 and 213 wherein the number average molecular weight (Mn) of L1is about 558. 72. The peptide modified polymer according to any one of clauses 1-71 and 213 wherein L1is selected from: divalent -C2to C8hydrocarbyl and wherein each R12is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, - OC1to C20alkyl, -NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I; wherein each R13is independently selected from: -H, -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, and - C2to C20alkynyl; and wherein each Z is independently selected from an integer from 0 to 4. 73. The peptide modified polymer according to clause 72 wherein each R12is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, - C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -NHC1to C20alkyl, - N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I. 74. The peptide modified polymer according to clause 72 or clause 73 wherein each R12is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20 cycloalkyl, -C2 to C20 alkenyl, -C2 to C20 alkynyl, -OH, -NH2, -OC1 to C20 alkyl, -F, -Cl, -Br, and -I. 75. The peptide modified polymer according to any one of clauses 72-74 wherein each R12is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -OH, -NH2, -OC1to C20alkyl, -F, -Cl, -Br, and -I. 76. The peptide modified polymer according to any one of clauses 72-75 wherein each R12is independently selected from: -C1 to C20 alkyl, -C1 to C20 haloalkyl, -C3 to C20 cycloalkyl, -OC1to C20alkyl, -F, -Cl, -Br, and -I. 77. The peptide modified polymer according to any one of clauses 72-76 wherein each R12is independently selected from: -C1to C20alkyl, -C3to C20cycloalkyl, -OC1to C20alkyl, -F, -Cl, -Br, and -I. 78. The peptide modified polymer according to any one of clauses 72-77 wherein each R12is independently selected from: -C1to C8alkyl, -C3to C8cycloalkyl, -OC1to C8alkyl, - F, -Cl, -Br, and -I. 79. The peptide modified polymer according to any one of clauses 72-78 wherein each R12is independently selected from: -C1to C8alkyl, -C3to C8cycloalkyl, -OC1to C8alkyl, - F, -Cl, -Br, and -I. 80. The peptide modified polymer according to any one of clauses 72-79 wherein each R12is independently selected from -C1to C8alkyl. 81. The peptide modified polymer according to any one of clauses 72-80 wherein each R13is independently selected from: -H, -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, and -C2to C20alkynyl. 82. The peptide modified polymer according to any one of clauses 72-81 wherein each R13is independently selected from: -H, -C1to C20alkyl, -C1to C20haloalkyl, -C2to C20alkenyl, and -C2to C20alkynyl. 83. The peptide modified polymer according to any one of clauses 72-82 wherein each R13is independently selected from: -H, -C1to C20alkyl, -C2to C20alkenyl, and -C2to C20alkynyl. 84. The peptide modified polymer according to any one of clauses 72-83 wherein each R13is independently selected from: -H, -C1to C20alkyl, and -C2to C20alkenyl. 85. The peptide modified polymer according to any one of clauses 72-84 wherein each R13is independently selected from: -H and -C1to C20alkyl. 86. The peptide modified polymer according to any one of clauses 72-85 wherein each R13is independently selected from: -H and -C1to C8alkyl. 87. The peptide modified polymer according to any one of clauses 72-86 wherein each R13is independently selected from -C1to C8alkyl. 88. The peptide modified polymer according to any one of clauses 72-86 wherein each R13is H. 89. The peptide modified polymer according to any one of clauses 72-88 wherein Z is independently selected from an integer from 0 to 4. 90. The peptide modified polymer according to any one of clauses 72-89 wherein Z is independently selected from an integer from 0 to 4, e.g.0, 1, 2, 3, or 4. 91. The peptide modified polymer according to any one of clauses 72-90 wherein Z is independently selected from an integer from 0 to 3. 92. The peptide modified polymer according to any one of clauses 72-91 wherein Z is independently selected from an integer from 0 to 2. 93. The peptide modified polymer according to any one of clauses 72-92 wherein Z is independently selected from an integer from 0 and 1. 94. The peptide modified polymer according to any one of clauses 72-90 wherein Z is selected from an integer from 0 to 4, e.g.0, 1, 2, 3, or 4. 95. The peptide modified polymer according to any one of clauses 1-94 and 213 wherein each R3is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyloxy, -C1to C20alkylamino, -C6to C14aryl optionally substituted with one or more R6groups, and -C2to C9heteroaryl optionally substituted with one or more R6groups; wherein said -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyloxy, or -C1to C20alkylamino group is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl-C3to C20cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C1to C20alkyloxy, -C1to C20alkylamino, -OH, -OR7, -NH2, -NHR7, - NR72, -C(O)OH, -C(O)OR7, -C(O)NH2, -C(O)NHR7, -C(O)NR72, -O(CO)H, -O(CO)R7, - NH(CO)H, -NH(CO)R7, -NR7(CO)H, -NR7(CO)R7, -SH, -SR7, -SO2H, -SO2R7, -SO3R7, - SO3H, -SiR73, -NO2, -CN, -F, -Cl, -Br, -I, -C6to C14aryl optionally substituted with one or more R8groups, and -C2to C9heteroaryl optionally substituted with one or more R8groups. 96. The peptide modified polymer according to any one of clauses 1-95 and 213 wherein each R3is independently selected from: -C1to C20alkyl, -C3to C20cycloalkyl, -C3 to C20 heterocycloalkyl, -C1 to C20 alkyloxy, -C1 to C20 alkylamino, -C6 to C14 aryl optionally substituted with one or more R6groups, and -C2to C9heteroaryl optionally substituted with one or more R6groups; wherein said -C1to C20alkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C1to C20alkyloxy, or -C1to C20alkylamino group is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20 alkynyl, -C1 to C20 alkyl-C6 to C14 aryl, -C1 to C20 alkyl-C2 to C9 heteroaryl, -C1 to C20 alkyl-C3to C20cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C1to C20alkyloxy, - C1to C20alkylamino, -OH, -OR7, -NH2, -NHR7, -NR72, -C(O)OH, -C(O)OR7, -C(O)NH2, - C(O)NHR7, -C(O)NR72, -O(CO)H, -O(CO)R7, -NH(CO)H, -NH(CO)R7, -NR7(CO)H, - NR7(CO)R7, -SH, -SR7, -SO2H, -SO2R7, -SO3R7, -SO3H, -SiR73, -NO2, -CN, -F, -Cl, -Br, -I, -C6to C14aryl optionally substituted with one or more R8groups, and -C2to C9heteroaryl optionally substituted with one or more R8groups. 97. The peptide modified polymer according to any one of clauses 1-96 and 213 wherein each R3is independently selected from: -C1to C20alkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C1to C20alkyloxy, and -C1to C20alkylamino; wherein said -C1to C20alkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C1to C20alkyloxy, or -C1to C20alkylamino group is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl-C3to C20cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C1to C20alkyloxy, -C1to C20alkylamino, -OH, -OR7, -NH2, -NHR7, - NR72, -C(O)OH, -C(O)OR7, -C(O)NH2, -C(O)NHR7, -C(O)NR72, -O(CO)H, -O(CO)R7, - NH(CO)H, -NH(CO)R7, -NR7(CO)H, -NR7(CO)R7, -SH, -SR7, -SO2H, -SO2R7, -SO3R7, - SO3H, -SiR73, -NO2, -CN, -F, -Cl, -Br, -I, -C6to C14aryl optionally substituted with one or more R8groups, and -C2to C9heteroaryl optionally substituted with one or more R8groups. 98. The peptide modified polymer according to any one of clauses 1-97 and 213 wherein each R3is independently selected from: -C1to C20alkyl and -C3to C20heterocycloalkyl; wherein said -C1to C20alkyl and -C3to C20heterocycloalkyl group is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C3to C20heterocycloalkyl, -OH, -OR7, -NH2, -NHR7, -NR72, -C(O)OH, -C(O)OR7, - C(O)NH2, -C(O)NHR7, -C(O)NR72, -O(CO)H, -O(CO)R7, -NH(CO)H, -NH(CO)R7, - NR7(CO)H, -NR7(CO)R7, -SH, -SR7, -SO2H, -SO2R7, -SO3R7, -SO3H, -SiR73, -NO2, -CN, - F, -Cl, -Br, -I, -C6 to C14 aryl optionally substituted with one or more R8groups, and -C2 to C9heteroaryl optionally substituted with one or more R8groups. 99. The peptide modified polymer according to any one of clauses 1-98 and 213 wherein each R3is independently selected from: -C1to C20alkyl and -C3to C20heterocycloalkyl; wherein said -C1to C20alkyl and -C3to C20heterocycloalkyl group is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C3 to C20 heterocycloalkyl, -OH, -OR7, -NH2, -NHR7, and -NR72. 100. The peptide modified polymer according to any one of clauses 1-99 and 213 wherein each R3is independently selected from: -C1to C20alkyl and -C3to C20heterocycloalkyl; wherein said -C1to C20alkyl and -C3to C20heterocycloalkyl group is optionally substituted with one or more group independently selected from: -OH. 101. The peptide modified polymer according to any one of clauses 1-100 and 213 wherein each R3is independently selected from: -C1to C8alkyl and -C3to C8heterocycloalkyl; wherein said -C1to C20alkyl and -C3to C20heterocycloalkyl group is optionally substituted with one or more group independently selected from: -OH. 102. The peptide modified polymer according to any one of clauses 1-101 and 213 wherein each R3is independently selected from: -C1to C8alkyl; wherein said -C1to C20alkyl group is optionally substituted with one or more group independently selected from: -OH. 103. The peptide modified polymer according to any one of clauses 1-101 and 213 wherein each R3is independently selected from: -C3to C8heterocycloalkyl. 104. The peptide modified polymer according to any one of clauses 1-102 and 213wherein R3 is selected from: , , and . 105. The peptide modified polymer according to any one of clauses 1-101 and 213wherein R3 is selected from: 106. The peptide modified polymer according to any one of clauses 1-96 and 213 wherein each R6is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3 to C20 cycloalkyl, -C2 to C20 alkenyl, -C2 to C20 alkynyl, -OH, -NH2, -OC1 to C20 alkyl, -NHC1 to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I. 107. The peptide modified polymer according to any one of clauses 1-96, 106, and 213 wherein each R6is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -F, - Cl, -Br, and -I. 108. The peptide modified polymer according to any one of clauses 1-96, 106, 107, and 213, wherein each R6is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -OH, -NH2, -OC1to C20alkyl, -F, -Cl, -Br, and -I. 109. The peptide modified polymer according to any one of clauses 1-96, 106-108, and 213 wherein each R6is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -OC1to C20alkyl, -F, -Cl, -Br, and -I. 110. The peptide modified polymer according to any one of clauses 1-96, 106-109, and 213, wherein each R6is independently selected from: -C1to C20alkyl, -C3to C20cycloalkyl, -OC1to C20alkyl, -F, -Cl, -Br, and -I. 111. The peptide modified polymer according to any one of clauses 1-96, 106-110, and 213, wherein each R6is independently selected from: -C1to C8alkyl, -C3to C8cycloalkyl, -OC1to C8alkyl, -F, -Cl, -Br, and -I. 112. The peptide modified polymer according to any one of clauses 1-96, 106-111, and 213, wherein each R6is independently selected from: -C1to C8alkyl, -C3to C8cycloalkyl, -OC1to C8alkyl, -F, -Cl, -Br, and -I. 113. The peptide modified polymer according to any one of clauses 1-96, 106-112, and 213, wherein each R6is independently selected from -C1to C8alkyl. 114. The peptide modified polymer according to any one of clauses 1-99, 106-113, and 213, wherein each R7is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl-C3to C10cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C1to C20alkoxy, -C1to C20alkylamino, -C6to C14aryl, and -C2to C9heteroaryl. 115. The peptide modified polymer according to any one of clauses 1-99, 106-114, and 213, wherein each R7is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl-C3to C10cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C6to C14aryl, and -C2to C9heteroaryl. 116. The peptide modified polymer according to any one of clauses 1-99, 106-115, and 213, wherein each R7is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C6to C14aryl, and - C2to C9heteroaryl. 117. The peptide modified polymer according to any one of clauses 1-99, 106-116, and 213, wherein each R7is independently selected from: -C1to C20alkyl, C3to C20cycloalkyl, -C3 to C20 heterocycloalkyl, -C2 to C20 alkenyl, -C6 to C14 aryl, and -C2 to C9 heteroaryl. 118. The peptide modified polymer according to any one of clauses 1-99, 106-117, and 213, wherein each R7is independently selected from: -C1to C20alkyl and -C2to C20alkenyl. 119. The peptide modified polymer according to any one of clauses 1-99, 106-118, and 213, wherein each R7is independently selected from -C1to C20alkyl. 120. The peptide modified polymer according to any one of clauses 1-99, 106-119, and 213, wherein each R7is independently selected from -C1to C8alkyl. 121. The peptide modified polymer according to any one of clauses 1-99, 106-120, and 213, wherein each R8is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, - NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I. 122. The peptide modified polymer according to any one of clauses 1-99, 106-121, and 213, wherein each R8is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, - F, -Cl, -Br, and -I. 123. The peptide modified polymer according to any one of clauses 1-99, 106-122, and 213, wherein each R8is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -OH, -NH2, -OC1to C20alkyl, -F, -Cl, -Br, and -I. 124. The peptide modified polymer according to any one of clauses 1-99, 106-123, and 213, wherein each R8is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -OC1to C20alkyl, -F, -Cl, -Br, and -I. 125. The peptide modified polymer according to any one of clauses 1-99, 106-124, and 213, wherein each R8is independently selected from: -C1to C20alkyl, -C3to C20cycloalkyl, -OC1to C20alkyl, -F, -Cl, -Br, and -I. 126. The peptide modified polymer according to any one of clauses 1-99, 106-125, and 213, wherein each R8is independently selected from: -C1to C8alkyl, -C3to C8cycloalkyl, -OC1to C8alkyl, -F, -Cl, -Br, and -I. 127. The peptide modified polymer according to any one of clauses 1-99, 106-126, and 213, wherein each R8is independently selected from: -C1to C8alkyl, -C3to C8cycloalkyl, -OC1to C8alkyl, -F, -Cl, -Br, and -I. 128. The peptide modified polymer according to any one of clauses 1-99, 106-127, and 213, wherein each R8is independently selected from -C1to C8alkyl. 129. The peptide modified polymer according to any one of clauses 2-128, wherein the radical species of Formula (D) is defined by Formula (D-I): wherein R9and L2are as defined herein. 130. The peptide modified polymer according to any one of clauses 2-129 wherein each R9is independently selected from: -H, -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, and -C2to C20alkynyl. 131. The peptide modified polymer according to any one of clauses 2-130 wherein each R9is independently selected from: -H, -C1to C20alkyl, -C1to C20haloalkyl, -C2to C20alkenyl, and -C2to C20alkynyl. 132. The peptide modified polymer according to any one of clauses 2-131 wherein each R9is independently selected from: -H, -C1to C8alkyl, -C1to C8haloalkyl, -C3to C8cycloalkyl, -C3to C8heterocycloalkyl, -C2to C8alkenyl, and -C2to C8alkynyl. 133. The peptide modified polymer according to any one of clauses 2-132 wherein each R9is independently selected from: -H, -C1to C20alkyl, -C2to C20alkenyl, and -C2to C20alkynyl. 134. The peptide modified polymer according to any one of clauses 2-133 wherein each R9is independently selected from: -H, -C1to C20alkyl, and -C2to C20alkenyl. 135. The peptide modified polymer according to any one of clauses 2-134 wherein each R9is independently selected from: -H and -C1to C20alkyl. 136. The peptide modified polymer according to any one of clauses 2-135 wherein each R9is independently selected from: -H and -C1to C8alkyl. 137. The peptide modified polymer according to any one of clauses 2-136 wherein each R9is independently selected from -C1to C8alkyl. 138. The peptide modified polymer according to any one of clauses 2-136 wherein each R9is H. 139. The peptide modified polymer according to any one of clauses 2-137 wherein each R9is not H. 140. The peptide modified polymer according to any one of clauses 2-137 and 139, wherein each R9is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, and -C2to C20alkynyl. 141. The peptide modified polymer according to any one of clauses 2-137, 139 and 140, wherein each R9is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C2to C20alkenyl, and -C2to C20alkynyl. 142. The peptide modified polymer according to any one of clauses 2-137 and 139-141, wherein each R9is independently selected from: -C1to C20alkyl, -C2to C20alkenyl, and - C2to C20alkynyl. 143. The peptide modified polymer according to any one of clauses 2-137 and 139-142, wherein each R9is independently selected from: -C1to C20alkyl, and -C2to C20alkenyl. 144. The peptide modified polymer according to any one of clauses 2-137 and 139-143, wherein each R9is independently selected from -C1to C20alkyl. 145. The peptide modified polymer according to any one of clauses 2-137 and 139-144, wherein each R9is independently selected from -C1to C8alkyl. 146. The peptide modified polymer according to any one of clauses 2-145 wherein L2is selected from: optionally substituted aliphatic (e.g. alkylene, alkenylene, or alkynylene), optionally substituted heteroaliphatic (e.g. heteroalkylene), optionally substituted carbocyclylene, optionally substituted heterocyclylene, optionally substituted arylene, optionally substituted heteroarylene, and a combination thereof. 147. The peptide modified polymer according to any one of clauses 2-146 wherein L2is selected from: substituted aliphatic, unsubstituted aliphatic, substituted heteroaliphatic, unsubstituted heteroaliphatic, substituted arylene, unsubstituted arylene, substituted heteroarylene, unsubstituted heteroarylene, and a combination thereof. 148. The peptide modified polymer according to any one of clauses 2-147 wherein L2is optionally substituted aliphatic (e.g. alkylene, alkenylene, or alkynylene). 149. The peptide modified polymer according to any one of clauses 2-148 wherein L2is optionally substituted alkylene. 150. The peptide modified polymer according to any one of clauses 2-149, wherein L2is alkylene. 151. The peptide modified polymer according to any one of clauses 2-150 wherein L2is alkylene wherein the carbon chain length is from 1 to 500, 1 to 400, 1 to 300, 1 to 200, 1 to 190, 1 to 180, 1 to 170, 1 to 160, 1 to 150, 1 to 140, 1 to 130, 1 to 120, 1 to 110, 1 to 100, 1 to 95, 1 to 90, 1 to 85, 1 to 80, 1 to 75, 1 to 70, 1 to 65, 1 to 60, 1 to 55, 1 to 50, 1 to 45, 1 to 40, 1 to 35, 1 to 30, 1 to 25, 1 to 20, 1 to 15, 1 to 10, or 1 to 5 carbon atoms. 152. The peptide modified polymer according to any one of clauses 2-151 wherein L2is –(CH2)m- and wherein m is from 1 to 500, 1 to 400, 1 to 300, 1 to 200, 1 to 190, 1 to 180, 1 to 170, 1 to 160, 1 to 150, 1 to 140, 1 to 130, 1 to 120, 1 to 110, 1 to 100, 1 to 95, 1 to 90, 1 to 85, 1 to 80, 1 to 75, 1 to 70, 1 to 65, 1 to 60, 1 to 55, 1 to 50, 1 to 45, 1 to 40, 1 to 35, 1 to 30, 1 to 25, 1 to 20, 1 to 15, 1 to 10, or 1 to 5. 153. The peptide modified polymer according to any one of clauses 2-152 wherein L2is , 154. The peptide modified polymer according to any one of clauses 2-153 wherein L2is divalent -C2to C8alkylene, for example . 155. The peptide modified polymer according to any one of clauses 2-154 wherein L2is a hydrophobic linker. 156. The peptide modified polymer according to any one of clauses 2-149 wherein L2is a hydrophilic linker e.g. a heteroalkylene or a PEG linker. 157. The peptide modified polymer according to any one of clauses 2-149 and 156, wherein L2is optionally substituted heteroalkylene. 158. The peptide modified polymer according to any one of clauses 2-149, 156, and 157, wherein L2is heteroalkylene. 159. The peptide modified polymer according to any one of clauses 2-137, 139-149, and 156-158, wherein L2is heteroalkylene and R9is not H. 160. The peptide modified polymer according to any one of clauses 2-137, 139-149, and 156-159, wherein L2is heteroalkylene wherein the chain length is from 1 to 500, 1 to 400, 1 to 300, 1 to 200, 1 to 190, 1 to 180, 1 to 170, 1 to 160, 1 to 150, 1 to 140, 1 to 130, 1 to 120, 1 to 110, 1 to 100, 1 to 95, 1 to 90, 1 to 85, 1 to 80, 1 to 75, 1 to 70, 1 to 65, 1 to 60, 1 to 55, 1 to 50, 1 to 45, 1 to 40, 1 to 35, 1 to 30, 1 to 25, 1 to 20, 1 to 15, 1 to 10, or 1 to 5 atoms. 161. The peptide modified polymer according to any one of clauses 2-137, 139-149, and 156-160 wherein ; wherein z is an integer selected from 0 to 250, for example z is 0 or 2. 162. The peptide modified polymer according to clause 161 wherein z is an integer selected from 0 to 250, 0 to 225, 0 to 200, 0 to 190, 0 to 180, 0 to 170, 0 to 160, 0 to 150, 0 to 140, 0 to 130, 0 to 120, 0 to 110, 0 to 100, 0 to 95, 0 to 90, 0 to 85, 0 to 80, 0 to 75, 0 to 70, 0 to 65, 0 to 60, 0 to 55, 0 to 50, 0 to 45, 0 to 40, 0 to 35, 0 to 30, 0 to 25, 0 to 20, 0 to 15, 0 to 10, or 0 to 5. 163. The peptide modified polymer according to any one of clauses 2-162 wherein the number average molecular weight (Mn) of L2is about 5000, about 4000, about 3000, about 2000, about 1000, about 950, about 900, about 850, about 800, about 750, about 700, about 650, about 600, about 550, about 500, about 450, about 400, about 350, about 300, about 250, about 200, about 150, about 100, about 80, about 60, about 40, or about 20. 164. The peptide modified polymer according to clause 154 wherein each R9is methyl, 165. The peptide modified polymer according to any one of clauses 2-164 wherein each R10is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl-C3to C10cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C1to C20alkoxy, -C1to C20alkylamino, -C6to C14aryl, and -C2to C9heteroaryl. 166. The peptide modified polymer according to any one of clauses 2-165 wherein each R10is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C1to C20alkyl-C6to C14aryl, - C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl-C3to C10cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C6to C14aryl, and -C2to C9heteroaryl. 167. The peptide modified polymer according to any one of clauses 2-166 wherein each R10is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C6to C14aryl, and -C2to C9heteroaryl. 168. The peptide modified polymer according to any one of clauses 2-167 wherein each R10is independently selected from: -C1to C20alkyl, C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C6to C14aryl, and -C2to C9heteroaryl. 169. The peptide modified polymer according to any one of clauses 2-168 wherein each R10is independently selected from: -C1to C20alkyl and -C2to C20alkenyl. 170. The peptide modified polymer according to any one of clauses 2-169 wherein each R10is independently selected from -C1to C20alkyl. 171. The peptide modified polymer according to any one of clauses 2-170 wherein each R10is independently selected from -C1to C8alkyl. 172. The peptide modified polymer according to any one of clauses 2-171 wherein each R11is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20 cycloalkyl, -C2 to C20 alkenyl, -C2 to C20 alkynyl, -OH, -NH2, -OC1 to C20 alkyl, -NHC1 to C20 alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I. 173. The peptide modified polymer according to any one of clauses 2-172 wherein each R11is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -F, -Cl, -Br, and -I. 174. The peptide modified polymer according to any one of clauses 2-173 wherein each R11is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -OH, -NH2, -OC1to C20alkyl, -F, -Cl, -Br, and -I. 175. The peptide modified polymer according to any one of clauses 2-174 wherein each R11is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -OC1to C20alkyl, -F, -Cl, -Br, and -I. 176. The peptide modified polymer according to any one of clauses 2-175 wherein each R11is independently selected from: -C1to C20alkyl, -C3to C20cycloalkyl, -OC1to C20alkyl, -F, -Cl, -Br, and -I. 177. The peptide modified polymer according to any one of clauses 2-176 wherein each R11is independently selected from: -C1to C8alkyl, -C3to C8cycloalkyl, -OC1to C8alkyl, - F, -Cl, -Br, and -I. 178. The peptide modified polymer according to any one of clauses 2-177 wherein each R11is independently selected from -C1to C8alkyl. 179. The peptide modified polymer according to any one of clauses 1-178 and 213 wherein R1consists of a peptide radical containing less than or equal to 50 amino acids; less than or equal to 40 amino acids, less than or equal to 30 amino acids, less than or equal to 28 amino acids, less than or equal to 26 amino acids, less than or equal to 24 amino acids, less than or equal to 22 amino acids, less than or equal to 20 amino acids, less than or equal to 18 amino acids, less than or equal to 16 amino acids, less than or equal to 14 amino acids, less than or equal to 12 amino acids, less than or equal to 10 amino acids, less than or equal to 9 amino acids, less than or equal to 8 amino acids, less than or equal to 7 amino acids, less than or equal to 6 amino acids, less than or equal to 5 amino acids, less than or equal to 4 amino acids, less than or equal to 3 amino acids, less than or equal to 2 amino acids, or 1 amino acid. 180. The peptide modified polymer according to any one of clauses 1-179 and 213 wherein R1consists of a peptide radical containing greater than or equal to 2 amino acids. It will readily be appreciated that this embodiment may be combined with the above embodiment to form ranges e.g. greater than or equal to 2 and less than or equal to 50 etc. 181. The peptide modified polymer according to any one of clauses 1-180 and 213 wherein the peptide radical is a linear or branched peptide radical. 182. The peptide modified polymer according to any one of clauses 1-181 and 213 wherein the peptide radical is a cyclic peptide radical. 183. The peptide modified polymer according to any one of clauses 1-182 and 213 wherein R1comprises natural and unnatural amino acids. 184. The peptide modified polymer according to any one of clauses 1-182 and 213 wherein R1consists of only natural amino acids. 185. The peptide modified polymer according to any one of clauses 1-183 and 213 wherein R1comprises at least one unnatural amino acid. 186. The peptide modified polymer according to any one of clauses 1-183, 185 and 213 wherein R1consists of only unnatural amino acids. 187. The peptide modified polymer according to any one of clauses 1-185 and 213 wherein R1comprises one or more amino acids selected from: Ala, Cys, Arg, Asp, Ser, Glu, Gln, Lys, Gly, His, and Sar. 188. The peptide modified polymer according to any one of clauses 1-181, 184, 187, and 213, wherein the radical of Formula (A) has the structure selected from:

[0002] . 189. The peptide modified polymer according to any one of clauses 1-181, 184, 187, and 213, wherein the radical of Formula (A) has the structure selected from:

[0003] . 190. The peptide modified polymer according to any one of clauses 1-188, and 213 wherein the radical of Formula (A) has a structure that is an epimer of a structure defined in clause 189. 191. The peptide modified polymer according to any one of clauses 1-188, and 213 wherein the radical of Formula (A) has a structure that is a diastereomer of a structure defined in clause 189. 192. The peptide modified polymer according to any one of clauses 1-188, and 213 wherein the radical of Formula (A) has a structure that is an enantiomer of a structures defined in any one of clauses 190 and 191. 193. The peptide modified polymer according to any one of clauses 1-188, and 213 wherein the radical of Formula (A) has a structure that is a diastereomer of a structure defined in clause 189, wherein two stereocentres have been inverted. 194. The peptide modified polymer according to any one of clauses 1-187, and 213 wherein the radical of Formula (A) is an N-terminus peptide nitrogen radical. 195. The peptide modified polymer according to any one of clauses 1-187, and 213 wherein the radical of Formula (A) is a C-terminus peptide carbon radical. 196. The peptide modified polymer according to any one of clauses 1-195, and 213 wherein each R1is a peptide radical defined by the structure: ; wherein each RXis a dipeptide or tripeptide radical; wherein each RYis a peptide diradical or is absent. 197. The peptide modified polymer according to clause 196 wherein each RXis a dipeptide radical. 198. The peptide modified polymer according to clause 196 wherein each RXis a tripeptide radical. 199. The peptide modified polymer according to any one of clauses 196-198 wherein each RYis a peptide diradical. 200. The peptide modified polymer according to any one of clauses 196-198 wherein each RYis absent such that the radical of Formula (A) having the structure of , is a radical of RX. 201. The peptide modified polymer according to any one of clauses 196-200 wherein RXconsists of only natural amino acids. 202. The peptide modified polymer according to any one of clauses 196-199 and 201, wherein RYconsists of only natural amino acids. 203. The peptide modified polymer according to any one of clauses 196-200 and 202 wherein RXconsists of only unnatural amino acids. 204. The peptide modified polymer according to any one of clauses 196-199, 201, and 203, wherein RYconsists of only unnatural amino acids. 205. The peptide modified polymer according to any one of clauses 196-200, 202, and 204, wherein RXcomprises natural and unnatural amino acids. 206. The peptide modified polymer according to any one of clauses 196-201, 203, and 205, wherein RYcomprises natural and unnatural amino acids. 207. The peptide modified polymer according to any one of clauses 196-200 and 202- 206, wherein RXcomprises at least one unnatural amino acid. 208. The peptide modified polymer according to any one of clauses 196-201 and 203- 207, wherein RYcomprises at least one unnatural amino acid. 209. The peptide modified polymer according to any one of clauses 196-202 and 205- 208, wherein each RXand each RYcomprise one or more amino acids selected from: Ala, Cys, Arg, Asp, Ser, Glu, Gln, Lys, Gly, His, and Sar. 210. The peptide modified polymer according to clause 209 wherein RYcomprises or consists of a peptide diradical selected from: and wherein * denotes the point of attachment to the radical of RX. 211. The peptide modified polymer according to clause 209 wherein each RXradical is

[0004] . 212. The peptide modified polymer according to clause 211 wherein each RXradical is

[0005] . 213. A peptide modified polymer for nucleic acid delivery comprising: a radical of Formula (A) having the structure: a diradical of Formula (B) having the structure: a diradical of Formula (C) having the structure: wherein: each radical of Formula (A) has one point of attachment to a diradical of Formula (B); each diradical of Formula (B) has two points of attachment to separate radicals independently selected from: Formula (A) and Formula (C); each diradical of Formula (C) has two points of attachment, each to a separate diradical of Formula (B); wherein each X is independently selected from: -O-, -S-, and -NRw-; wherein each Y is independently selected from: =O, =S, and -OH; wherein L1is a hydrocarbyl linker comprising 1 to 500 carbon atoms; wherein R1comprises a peptide radical; wherein each R2is independently selected from: -H, -C1to C20alkyl; -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, and -C2to C20alkynyl; wherein said -C1to C20alkyl; -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, or -C2to C20alkynyl group is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -OR4, -NH2, -NHR4, -NR42, -C(O)OH, -C(O)OR4, -C(O)NH2, -C(O)NHR4, -C(O)NR42, - O(CO)H, -O(CO)R4, -NH(CO)H, -NH(CO)R4, -NR4(CO)H, -NR4(CO)R4, -SH, -SR4, -SO2H, -SO2R4, -SO3R4, -SO3H, -SiR43, -NO2, -CN, -F, -Cl, -Br, -I, -C6to C14aryl optionally substituted with one or more R5groups, and -C2to C9heteroaryl optionally substituted with one or more R5groups; wherein each R3is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyloxy, -C1to C20alkylamino, -C6to C14aryl optionally substituted with one or more R6groups, and -C2to C9heteroaryl optionally substituted with one or more R6groups; wherein said -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyloxy, or -C1to C20alkylamino group is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl-C3to C20cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C1to C20alkyloxy, -C1to C20alkylamino, -OH, -OR7, -NH2, -NHR7, - NR72, -C(O)OH, -C(O)OR7, -C(O)NH2, -C(O)NHR7, -C(O)NR72, -O(CO)H, -O(CO)R7, - NH(CO)H, -NH(CO)R7, -NR7(CO)H, -NR7(CO)R7, -SH, -SR7, -SO2H, -SO2R7, -SO3R7, - SO3H, -SiR73, -NO2, -CN, -F, -Cl, -Br, -I, -C6to C14aryl optionally substituted with one or more R8groups, and -C2 to C9 heteroaryl optionally substituted with one or more R8groups; wherein each R4is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl- C3to C10cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C1to C20alkoxy, -C1to C20 alkylamino, -C6 to C14 aryl, and -C2 to C9 heteroaryl; wherein each R5is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I; wherein each R6is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I; wherein each R7is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl- C3to C10cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C1to C20alkoxy, -C1to C20alkylamino, -C6to C14aryl, and -C2to C9heteroaryl; wherein each R8is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I; and wherein each Rwis independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, and -C2to C20alkenyl. 214. The peptide modified polymer according to any one of clauses 1-178 and 213 wherein R1comprises a peptide radical containing less than or equal to 50 amino acids; less than or equal to 40 amino acids, less than or equal to 30 amino acids, less than or equal to 28 amino acids, less than or equal to 26 amino acids, less than or equal to 24 amino acids, less than or equal to 22 amino acids, less than or equal to 20 amino acids, less than or equal to 18 amino acids, less than or equal to 16 amino acids, less than or equal to 14 amino acids, less than or equal to 12 amino acids, less than or equal to 10 amino acids, less than or equal to 9 amino acids, less than or equal to 8 amino acids, less than or equal to 7 amino acids, less than or equal to 6 amino acids, less than or equal to 5 amino acids, less than or equal to 4 amino acids, less than or equal to 3 amino acids, less than or equal to 2 amino acids, or 1 amino acid. 215. The peptide modified polymer according to any one of clauses 1-178, 213, and 214 wherein R1comprises a peptide radical containing greater than or equal to 2 amino acids. It will readily be appreciated that this embodiment may be combined with the above embodiment to form ranges e.g. greater than or equal to 2 and less than or equal to 50 etc. 216. The peptide modified polymer according to any one of clauses 1-178 and 213-215 wherein R1comprises a linear or branched peptide radical. 217. The peptide modified polymer according to any one of clauses 1-178 and 213-216 wherein R1comprises a cyclic peptide radical. 218. The peptide modified polymer according to any one of clauses 1-178 and 213-217 wherein R1comprises natural and unnatural amino acids. 219. The peptide modified polymer according to any one of clauses 1-178 and 213-217 wherein R1comprises only natural amino acids. 220. The peptide modified polymer according to any one of clauses 1-178 and 213-218 wherein R1comprises at least one unnatural amino acid. 221. The peptide modified polymer according to any one of clauses 1-178, 220 and 213- 218 wherein R1comprises only unnatural amino acids. 222. The peptide modified polymer according to any one of clauses 1-178 and 213-220 wherein R1comprises one or more amino acids selected from: Ala (A), Cys (C), Arg (R), Asp (D), Ser (S), Glu (E), Gln (Q), Lys (K), Gly (G), His (H), and Sar. 223. The peptide modified polymer according to any one of clauses 1-178, 213-216, 219, and 222, wherein the radical of Formula (A) comprises the structure selected from:

[0006] . 224. The peptide modified polymer according to any one of clauses 1-178, 213-216, 219, and 222, wherein the radical of Formula (A) comprises the structure selected from:

[0007] . 225. The peptide modified polymer according to any one of clauses 1-178, and 213-223 wherein the radical of Formula (A) comprises a structure that is an epimer of a structure defined in clause 224. 226. The peptide modified polymer according to any one of clauses 1-178, and 213-223 wherein the radical of Formula (A) comprises a structure that is a diastereomer of a structure defined in clause 224. 227. The peptide modified polymer according to any one of clauses 1-178, and 213-223 wherein the radical of Formula (A) comprises a structure that is an enantiomer of a structures defined in any one of clauses 225 and 226. 228. The peptide modified polymer according to any one of clauses 1-178, and 213-223 wherein the radical of Formula (A) comprises a structure that is a diastereomer of a structure defined in clause 224, wherein two stereocentres have been inverted. 229. The peptide modified polymer according to any one of clauses 1-178, and 213-222 wherein the radical of Formula (A) comprises an N-terminus peptide nitrogen radical. 230. The peptide modified polymer according to any one of clauses 1-178, and 213-222 wherein the radical of Formula (A) comprises a C-terminus peptide carbon radical. 231. The peptide modified polymer according to any one of clauses 1-178 and 213-230, wherein each R1is a radical defined by the structure: ; wherein each RXis a dipeptide or tripeptide radical; wherein each RYis a peptide diradical or is absent; and wherein each L3is a hydrocarbyl linker comprising 1 to 100 carbon atoms, for example 1 to 20 carbon atoms, such as 1 to 10 carbon atoms. 232. The peptide modified polymer according to clause 231 wherein each RXis a dipeptide radical. 233. The peptide modified polymer according to clause 231 wherein each RXis a tripeptide radical. 234. The peptide modified polymer according to any one of clauses 231-233 wherein each RYis a peptide diradical. 235. The peptide modified polymer according to any one of clauses 231-233 wherein each RYis absent such that the radical of Formula (A) having the structure of , is a radical of RX-L3-. 236. The peptide modified polymer according to any one of clauses 231-235 wherein RXconsists of only natural amino acids. 237. The peptide modified polymer according to any one of clauses 231-234 and 236, wherein RYconsists of only natural amino acids. 238. The peptide modified polymer according to any one of clauses 231-235 and 237 wherein RXconsists of only unnatural amino acids. 239. The peptide modified polymer according to any one of clauses 231-234, 236, and 238, wherein RYconsists of only unnatural amino acids. 240. The peptide modified polymer according to any one of clauses 231-235, 237, and 239, wherein RXcomprises natural and unnatural amino acids. 241. The peptide modified polymer according to any one of clauses 231-236, 238, and 240, wherein RYcomprises natural and unnatural amino acids. 242. The peptide modified polymer according to any one of clauses 231-235 and 237- 241, wherein RXcomprises at least one unnatural amino acid. 243. The peptide modified polymer according to any one of clauses 231-236 and 238- 242, wherein RYcomprises at least one unnatural amino acid. 244. The peptide modified polymer according to any one of clauses 231-237 and 240- 243, wherein each RXand each RYcomprise one or more amino acids selected from: Ala, Cys, Arg, Asp, Ser, Glu, Gln, Lys, Gly, His, and Sar. 245. The peptide modified polymer according to clause 244 wherein RYcomprises or consists of a peptide diradical selected from:

[0008] and wherein * denotes the point of attachment to the radical of RX. 246. The peptide modified polymer according to clause 244 wherein each RXradical is

[0009] . 247. The peptide modified polymer according to clause 246 wherein each RXradical is selected from: , 248. The peptide modified polymer according to any one of clauses 231-247, wherein L3is a diradical defined wherein denotes the point of attachment to the radical of RY(if RYis present) or RX(if RYis absent). 249. The peptide modified polymer according to any one of clauses 231-248, wherein each RXand each RYcomprise one or more amino acids selected from: Ala (A), Cys (C), Arg (R), Asp (D), Ser (S), Glu (E), Gln (Q), Lys (K), Gly (G), His (H), and Sar, for example wherein each RXand / or each RYcomprise one or more Cys (C); or wherein RYis absent. 250. The peptide modified polymer according to any one of clauses 231-249, wherein each selected from: DGRCG-NH2(RGD), DGRGGCG-NH2(G2RGD), DGRGGGGCG-NH2(G4RGD), DGRGGGGGGCG-NH2(G6RGD), DGRGGGGGGGGCG-NH2(G8RGD), DGRAACG-NH2(A2RGD), DGRAAAACG-NH2(A4RGD), DGRAAAAAACG-NH2(A6RGD), DGRAAAAAAAACG-NH2(A8RGD), DGRKECG-NH2(EK2RGD), DGRKEKECG-NH2(EK4RGD), DGRKEKEKECG-NH2(EK6RGD), DGRKEKEKEKECG-NH2 (EK8RGD), GDRCG-NH2 (RDG), EGRCG-NH2 (RGE), GDRKECG-NH2(EKRDG), and EGRKECG-NH2(EKRGE). 251. The peptide modified polymer according to any one of clauses 231-249, wherein the point of attachment of RYto L3is via a Cys (C) sulfur atom. In one aspect, the present invention provides a peptide modified polymer for nucleic acid delivery comprising: a radical of Formula (A) having the structure: a diradical of Formula (B) having the structure: a diradical of Formula (C) having the structure: wherein: each radical of Formula (A) has one point of attachment to a diradical of Formula (B); each diradical of Formula (B) has two points of attachment to separate radicals independently selected from: Formula (A) and Formula (C); each diradical of Formula (C) has two points of attachment, each to a separate diradical of Formula (B); wherein each X is independently selected from: -O-, -S-, and -NRw-; wherein each Y is independently selected from: =O, =S, and -OH; wherein L1is a hydrocarbyl linker comprising 1 to 500 carbon atoms; wherein R1comprises a peptide radical; wherein each R2is independently selected from: -H, -C1to C20alkyl; -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, and -C2to C20alkynyl; wherein said -C1to C20alkyl; -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, or -C2to C20alkynyl group is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -OR4, -NH2, -NHR4, -NR42, -C(O)OH, -C(O)OR4, -C(O)NH2, -C(O)NHR4, -C(O)NR42, - O(CO)H, -O(CO)R4, -NH(CO)H, -NH(CO)R4, -NR4(CO)H, -NR4(CO)R4, -SH, -SR4, -SO2H, -SO2R4, -SO3R4, -SO3H, -SiR43, -NO2, -CN, -F, -Cl, -Br, -I, -C6to C14aryl optionally substituted with one or more R5groups, and -C2to C9heteroaryl optionally substituted with one or more R5groups; wherein each R3is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyloxy, -C1to C20alkylamino, -C6to C14aryl optionally substituted with one or more R6groups, and -C2to C9heteroaryl optionally substituted with one or more R6groups; wherein said -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyloxy, or -C1to C20alkylamino group is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl-C3to C20cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C1to C20alkyloxy, -C1to C20alkylamino, -OH, -OR7, -NH2, -NHR7, - NR72, -C(O)OH, -C(O)OR7, -C(O)NH2, -C(O)NHR7, -C(O)NR72, -O(CO)H, -O(CO)R7, - NH(CO)H, -NH(CO)R7, -NR7(CO)H, -NR7(CO)R7, -SH, -SR7, -SO2H, -SO2R7, -SO3R7, - SO3H, -SiR73, -NO2, -CN, -F, -Cl, -Br, -I, -C6to C14aryl optionally substituted with one or more R8groups, and -C2 to C9 heteroaryl optionally substituted with one or more R8groups; wherein each R4is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl- C3to C10cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C1to C20alkoxy, -C1to C20 alkylamino, -C6 to C14 aryl, and -C2 to C9 heteroaryl; wherein each R5is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I; wherein each R6is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I; wherein each R7is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl- C3to C10cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C1to C20alkoxy, -C1to C20alkylamino, -C6to C14aryl, and -C2to C9heteroaryl; wherein each R8is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I; and wherein each Rwis independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, and -C2to C20alkenyl. The present invention provides a peptide modified polymer for nucleic acid delivery comprising: a radical of Formula (A) having the structure: a diradical of Formula (B) having the structure: a diradical of Formula (C) having the structure: wherein: each radical of Formula (A) has one point of attachment to a diradical of Formula (B); each diradical of Formula (B) has two points of attachment to separate radicals independently selected from: Formula (A) and Formula (C); each diradical of Formula (C) has two points of attachment, each to a separate diradical of Formula (B); wherein each X is independently selected from: -O-, -S-, and -NRw-; wherein each Y is independently selected from: =O, =S, and -OH; wherein L1is a hydrocarbyl linker comprising 1 to 500 carbon atoms; wherein R1is a peptide radical; wherein each R2is independently selected from: -H, -C1to C20alkyl; -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, and -C2to C20alkynyl; wherein said -C1to C20alkyl; -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, or -C2to C20alkynyl group is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -OR4, -NH2, -NHR4, -NR42, -C(O)OH, -C(O)OR4, -C(O)NH2, -C(O)NHR4, -C(O)NR42, - O(CO)H, -O(CO)R4, -NH(CO)H, -NH(CO)R4, -NR4(CO)H, -NR4(CO)R4, -SH, -SR4, -SO2H, -SO2R4, -SO3R4, -SO3H, -SiR43, -NO2, -CN, -F, -Cl, -Br, -I, -C6to C14aryl optionally substituted with one or more R5groups, and -C2to C9heteroaryl optionally substituted with one or more R5groups; wherein each R3is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyloxy, -C1to C20alkylamino, -C6to C14aryl optionally substituted with one or more R6groups, and -C2to C9heteroaryl optionally substituted with one or more R6groups; wherein said -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20 heterocycloalkyl, -C2 to C20 alkenyl, -C2 to C20 alkynyl, -C1 to C20 alkyloxy, or -C1 to C20 alkylamino group is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl-C3to C20cycloalkyl, -C1to C20alkyl-C3to C10 heterocycloalkyl, -C1 to C20 alkyloxy, -C1 to C20 alkylamino, -OH, -OR7, -NH2, -NHR7, - NR72, -C(O)OH, -C(O)OR7, -C(O)NH2, -C(O)NHR7, -C(O)NR72, -O(CO)H, -O(CO)R7, - NH(CO)H, -NH(CO)R7, -NR7(CO)H, -NR7(CO)R7, -SH, -SR7, -SO2H, -SO2R7, -SO3R7, - SO3H, -SiR73, -NO2, -CN, -F, -Cl, -Br, -I, -C6to C14aryl optionally substituted with one or more R8groups, and -C2to C9heteroaryl optionally substituted with one or more R8groups; wherein each R4is independently selected from: -C1 to C20 alkyl, -C1 to C20 haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl- C3to C10cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C1to C20alkoxy, -C1to C20alkylamino, -C6to C14aryl, and -C2to C9heteroaryl; wherein each R5is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I; wherein each R6is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I; wherein each R7is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl- C3to C10cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C1to C20alkoxy, -C1to C20alkylamino, -C6to C14aryl, and -C2to C9heteroaryl; wherein each R8is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I; and wherein each Rwis independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, and -C2to C20alkenyl. In another aspect the present invention provides a composition comprising a peptide modified polymer as defined herein in addition to a polynucleotide, or a nanoparticle composition as defined herein; and a pharmaceutically acceptable excipient. In another aspect the present invention provides a nasal spray comprising the composition as defined herein. In another aspect the present invention provides an in vitro method of delivering polynucleotides to cells, the method comprising contacting the composition as defined herein, or the nasal spray as defined herein, with said cells. In another aspect the present invention provides a composition as defined herein, or a nasal spray as defined herein, for use in treating a disease or disorder. In another aspect the present invention provides a method for preparing a peptide modified polymer as defined herein, the method comprising the steps of: (i) contacting an amine having the structure of Formula (I): H2N-R3, with an alkene having the structure of Formula (II): in an organic solvent; (ii) agitating and optionally heating the solution of step (i); (iii) contacting the reaction mixture with a peptide of Formula (VI): R1-H; and (iv) agitating the reaction mixture; to thereby prepare the peptide modified polymer; wherein each R1, R2, R9, L1, L2, X, and Y are as defined herein. In another aspect the present invention provides a method for preparing a peptide modified polymer as defined herein, the method comprising the steps of: (i) contacting an amine having the structure of Formula (I): H2N-R3, e structure of Formula (II): in an organic solvent; (ii) agitating and optionally heating the solution of step (i); (iii) contacting the reaction mixture with 5-norbornene-2-methylamine; (iv) agitating and optionally heating the solution of step (iii); (v) contacting the product of step (iv) with a photoinitiator and a peptide of Formula (VI): R1-H in an organic solvent, wherein R1is a peptide; (vi) agitating and irradiating the solution of step (v); to thereby prepare the peptide modified polymer; wherein each R1, R2, R9, L1, L2, L3, X, and Y are as defined by any of the preceding claims. In another aspect the present invention provides a method for preparing a nanoparticle composition as defined herein, the method comprising the steps of: (i) providing the peptide modified polymer as defined herein in an organic solvent; (ii) combining the organic solvent with an aqueous buffer; (iii) suspending a polynucleotide in water or an aqueous buffer, for example a sodium citrate buffer or phosphate-buffered saline (PBS); (iv) combining the mixture produced by step (ii) with the mixture produced by step (iii); to thereby prepare the nanoparticle composition. BRIEF DESCRIPTION OF THE DRAWINGS FIG.1 shows the proton NMR spectra of a) an uncapped acrylate-mine adduct “Uncapped A24” used in the preparation of peptide modified polymers, and b) a peptide modified polymer “A24-GlySar”. FIG.2 shows the proton NMR spectra of a) a peptide modified polymer “DD90- GlySar” and b) a peptide modified polymer “DD90-AlaLys”. FIG.3 shows the proton NMR spectra of uncapped DD90 (acrylate terminated). FIG. 4 shows a) mRNA movement during electrophoresis, and b) a ribogreen assay showing encapsulation efficiency. FIG.5 shows a) SLC15A2 gene expression in primary human bronchial epithelial cells cultured submerged or at air liquid interface, b) PEPT2 protein expression in KRT5+ primary HBECS cultured in submerged conditions, or c) at the apical surface of air liquid interface culture, and d) AMCA-AlaLys uptake is greater at air-liquid interface compared to submerged cultures. FIG.6 shows a) peptide modified polymer complexed with firefly luciferase mRNA and delivered apically to primary HBECs cultured at ALI for a) 7 days, and b) 14 days. FIG. 6 also shows cytotoxicity of transfection as assessed by lactate dehydrogenase release was minimal at both c) 7 days, and d) 14 days. FIG.7 shows a) comparison of free peptides formulated with uncapped DD90 (+) and peptide conjugated-DD90, and d) immortalised HBEC cultured at air-liquid interface for 14 days and transfected apically with mRNA encoding firefly luciferase complexed with peptide or amine end-capped PBAE. FIG.8 shows DD90-GlySar : mRNA data: (a) size expressed as z-average mean diameter, and (b) ζ-potential. FIG.9 shows DD90-AlaLys : mRNA data: (a) size expressed as z-average mean diameter, and (b) ζ-potential. FIG.10 shows bDD90-118 : A24-GlySar : saRNA data: (a) size expressed as z- average mean diameter, and (b) ζ-potential. FIG.11 shows a schematic for Peptide-PBAE synthesis using DD90 backbone and cysteine containing peptide. H1NMR spectrum of DD90 backbone (to), norbornene end capped DD90-Nb (middle) and peptide (GCRGD) end capped DD90-peptide (bottom). Polymer was dissolved in DMSO-d6 at 10 mg / mL and analysed by proton NMR. The results show effective conjugation of norbornene to DD90-Ac backbone by confirming absence of ‘Ha’ peaks and presence of Hb peaks. Conjugation of the peptide to DD90-Nb is confirmed in the last panel showing absence of Hb peaks after addition of peptide, photoinitiator and UV. FIG.12 shows flow cytometry assessment of Cy5 tagged GFP mRNA uptake and translation in Jurkat cells using DD90-peptide compared to blank control and non-modified DD90-Nb control. Peptide ID in table 1. Polymer was complexed with mRNA at 50:1 mass ratio and 50 ng of mRNA transferred to each well of a 96 well containing 150,000 cells in 150 uL media. Cells were collected after 24 hours and washed in PBS by centrifugation and assessed by flow cytometry. The data shows the improvement of cell uptake of mRNA (Cy5 signal) is increased when different linkers are used, compared to control RGD with no linker ‘0RGD’ or control uncapped PBAE with norbornene end group ‘Nb’. The identity of optimal linked are not obvious. Linkers with the highest mRNA uptake also tended to have the highest GFP expression (mRNA translation). FIG.13 shows Cy5 tagged GFP mRNA delivery to adherent cells, (A) 16HBE or (B) human bone marrow stem cells (hBMSC). mRNA was complexed with DD90-peptide compared to non-modified DD90-Nb. Polymers were complexed with mRNA at 50:1 mass ratio and 50 ng of mRNA transferred to cells in a 96 well plate. Cells were fixed after 24 hours in paraformaldehyde and DAPI stained. Imaged using 10x objective. As found in FIG. 12, the PBAE with GCEK peptide linker termed ‘DD90-EK2RGD’ achieved higher translation of GFP mRNA compared to DD90 conjugated to RGD with no linker ‘DD90- RGD’. This supports findings that the linker plays an important role in cell uptake of RGD modified PBAEs. DETAILED DESCRIPTION Definitions Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Singleton, et al., DICTIONARY OF MICROBIOLOGY AND MOLECULAR BIOLOGY, 20 ED., John Wiley and Sons, New York (1994), and Hale & Marham, THE HARPER COLLINS DICTIONARY OF BIOLOGY, Harper Perennial, NY (1991) provide the skilled person with a general dictionary of many of the terms used in this disclosure. The meaning and scope of the terms should be clear; however, in the event of any latent ambiguity, definitions provided herein take precedent over any dictionary or extrinsic definition. It should be understood that this invention is not limited to the particular methodology, protocols, and reagents, etc., described herein and as such can vary. This invention is not limited by the exemplary methods and materials disclosed herein, and any methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of this invention. The terminology used herein is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention, which is defined solely by the appended claims. The description of embodiments of the invention is not intended to be exhaustive or to limit the invention to the precise form disclosed. While specific embodiments of, and examples for, the invention are described herein for illustrative purposes, various equivalent modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize. The various embodiments described herein can be combined to provide further embodiments. These and other changes can be made to the invention in the light of the detailed description. All such modifications are intended to be included within the scope of the appended claims. The headings provided herein are not limitations of the various aspects or embodiments of this invention. The term “administering” as used herein as a means of providing a nanoparticle composition comprising a polynucleotide, or a composition thereof, to a subject in a manner that results in the nanoparticle composition comprising a polynucleotide being on or inside the subject’s body. Such an administration can be by any route including, without limitation, oral, transdermal (e.g. vagina, rectum, oral mucosa), by injection (e.g. subcutaneous, intravenous, parenterally, intraperitoneally, into the CNS), or by inhalation (e.g. oral or nasal). Pharmaceutical preparations are, of course, given by forms suitable for each administration route. The term “active agent” as used herein refers to a chemical or biological substance capable of utility in a therapeutic application. In some embodiments the active agent is an active pharmaceutical ingredient, e.g. a polynucleotide. In some embodiments the active agent is a prodrug of an active pharmaceutical ingredient. In some embodiments the active agent is an active pharmaceutical ingredient or a prodrug of an active pharmaceutical ingredient. In the context of therapy, the term “prodrug” as used herein refers to a pharmacological derivative of a parent molecule that requires biotransformation, either spontaneous or enzymatic, within the organism to release the active drug. In the context of agrochemicals, the term “prodrug” as used herein refers to an agrochemical derivative of a parent molecule that requires transformation, for example biotransformation, either spontaneous or enzymatic, either within the organism or on the surface of the organism, to release the active agrochemical ingredient. For example, prodrugs are variations of derivatives of an active pharmaceutical ingredient or an agrochemical ingredient that have groups cleavable under certain conditions, for example metabolic conditions, which when cleaved become the active pharmaceutical ingredient or agrochemical ingredient. In the context of therapy, such prodrugs then are pharmaceutically active in vivo, when they undergo solvolysis under physiological conditions or undergo enzymatic degradation. In the context of agrochemicals, such prodrugs then are agrochemically active in vivo, when they undergo solvolysis under physiological conditions or undergo enzymatic degradation. In the context of agrochemicals, such prodrugs may additionally be active ex vivo, for example on the surface of an organism, for example when applied to a leaf, when they undergo solvolysis or enzymatic degradation. In the context of therapy, prodrugs often offer advantages of solubility, tissue compatibility, or delayed release in the mammalian organism. In the context of agrochemicals, prodrugs often offer advantages of administration, permeability, absorption, and distribution of the agrochemical ingredient. As used herein, the term “ALI” refers to air liquid interface. The term "alkyl" as used herein refers to a monovalent straight- or branched-chain alkyl moiety. Unless specifically indicated otherwise, the term “alkyl” does not include optional substituents. The term "haloalkyl" as used herein refers to an alkyl group substituted with one or more halo atoms. The term "halo" as used herein refers to any of fluorine, chlorine, bromine, or iodine. The term "alkylene," by itself or as part of another substituent, means, unless otherwise stated, a divalent radical derived from an alkyl, as exemplified, but not limited by, -CH2CH2CH2CH2CH2-. A "lower alkyl" or "lower alkylene" is a shorter chain alkyl or alkylene group, generally having eight or fewer carbon atoms. The term "alkenylene" by itself or as part of another substituent, means, unless otherwise stated, a divalent radical derived from an alkene. The term "alkynylene" by itself or as part of another substituent, means, unless otherwise stated, a divalent radical derived from an alkyne. The term "cycloalkyl" as used herein refers to a monovalent saturated aliphatic hydrocarbyl moiety containing at least one ring, wherein said ring has at least 3 ring carbon atoms. The cycloalkyl groups mentioned herein may optionally have alkyl groups attached thereto. Examples of cycloalkyl groups include groups that are monocyclic, polycyclic (e.g., bicyclic) or bridged ring system. Examples of cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and the like. The term "heterocycloalkyl" as used herein refers to a cycloalkyl group wherein the ring contains at least one heteroatom selected from oxygen, nitrogen, and sulphur. Examples of heterocycloalkyl groups include morpholine, piperidine, piperazine and the like. As used herein, the term “comprising” or “comprises” is intended to mean that the compositions and methods include the recited elements, but not excluding others. “Consisting essentially of” when used to define compositions and methods, shall mean excluding other elements of any essential significance to the combination for the stated purpose. Thus, a composition consisting essentially of the elements as defined herein would not exclude trace contaminants from the isolation and purification method and pharmaceutically acceptable carriers, such as phosphate buffered saline, preservatives and the like. “Consisting of” shall mean excluding more than trace elements of other ingredients and substantial method steps for administering the compositions of this invention or process steps to produce a composition or achieve an intended result. Embodiments defined by each of these transition terms are within the scope of this invention. Use of the term “comprising” herein is intended to encompass “consisting essentially of” and “consisting of”. The term “encapsulation efficiency” as used herein is defined as the percentage of the total drug added that was encapsulated in nanoparticles. The term "halo" as used herein refers to any of fluorine, chlorine, bromine, or iodine. The term "heteroalkyl," by itself or in combination with another term, means, unless otherwise stated, a stable straight or branched non-cyclic chain, or combinations thereof, including at least one carbon atom and at least one heteroatom (e.g., selected from the group consisting of O, N, P, Si, and S, and wherein the nitrogen and sulfur atoms may optionally be oxidized, and the nitrogen heteroatom may optionally be quaternised). The heteroatom(s) (e.g., O, N, P, S, and Si) may be placed at any interior position of the heteroalkyl group or at the position at which the alkyl group is attached to the remainder of the molecule. Examples include, but are not limited to: -CH2-CH2-O-CH3,-CH2-CH2-NH- CH3,-CH2-CH2-N(CH3)-CH3, -CH2-S-CH2-CH3,-CH2-CH2, -S(O)-CH3, -CH2-CH2-S(O)2- CH3, -CH=CH-O-CH3, -Si(CH3)3, -CH2-CH=N-OCH3, -CH=CH-N(CH3)-CH3, -O-CH3,-O- CH2-CH3, and -CN. Up to two or three heteroatoms may be consecutive, such as, for example, -CH2-NH-OCH3and ‒CH2-O-Si(CH3)3. The term "heteroalkenyl," by itself or in combination with another term, means, unless otherwise stated, a heteroalkyl including at least one double bond. A heteroalkenyl may optionally include more than one double bond and / or one or more triple bonds in additional to the one or more double bonds. The term "heteroalkynyl" by itself or in combination with another term, means, unless otherwise stated, a heteroalkyl including at least one triple bond. A heteroalkynyl may optionally include more than one triple bond and / or one or more double bonds in additional to the one or more triple bonds. Similarly, the term "heteroalkylene," by itself or as part of another substituent, means, unless otherwise stated, a divalent radical derived from heteroalkyl, as exemplified, but not limited by, -CH2-CH2-O-. For heteroalkylene groups, heteroatoms can also occupy either or both of the chain termini (e.g., alkyleneoxy, alkylenedioxy, alkyleneamino, alkylenediamino, and the like). Still further, for alkylene and heteroalkylene linking groups, no orientation of the linking group is implied by the direction in which the formula of the linking group is written. For example, the formula -C(O)2R'- represents both -C(O)2R'- and -R'C(O)2-. As described above, heteroalkyl groups, as used herein, include those groups that are attached to the remainder of the molecule through a heteroatom, such as -C(O)R', -C(O)NR', -NR'R", -OR', -SR', and / or -SO2R'. Where "heteroalkyl" is recited, followed by recitations of specific heteroalkyl groups, such as -NR'R" or the like, it will be understood that the terms heteroalkyl and -NR'R" are not redundant or mutually exclusive. Rather, the specific heteroalkyl groups are recited to add clarity. Thus, the term "heteroalkyl" should not be interpreted herein as excluding specific heteroalkyl groups, such as -NR'R" or the like. The term "heteroaryl" as used herein refers to an aromatic ring containing the indicated number of atoms (e.g., 5 to 20, 5 to 12, or 5 to 10 membered heteroaryl) made up of one or more heteroatoms (e.g., 1, 2, 3 or 4 heteroatoms) selected from N, O, and S and with the remaining ring atoms being carbon. Heteroaryl groups do not contain adjacent Sand O atoms. In some embodiments, the total number of S and O atoms in the heteroaryl group is not more than 2. In some embodiments, the total number of S and O atoms in the heteroaryl group is not more than 1. Unless otherwise indicated, heteroaryl groups may be bound to the parent structure by a carbon or nitrogen atom, as valency permits. For example, "pyridyl" includes 2-pyridyl, 3-pyridyl and 4-pyridyl groups, and "pyrrolyl" includes 1-pyrrolyl, 2-pyrrolyl and 3-pyrrolyl groups. In some embodiments, a heteroaryl group is monocyclic. Examples include pyrrole, pyrazole, imidazole, triazole ( e.g., 1,2,3-triazole, 1,2,4-triazole, 1,2,4-triazole ), tetrazole, furan, isoxazole, oxazole, oxadiazole (e.g., 1,2,3-oxadiazole, 1,2,4-oxadiazole, 1,3,4- oxadiazole), thiophene, isothiazole, thiazole, thiadiazole (e.g., 1,2,3-thiadiazole, 1,2,4- thiadiazole, 1,3,4-thiadiazole), pyridine, pyridazine, pyrimidine, pyrazine, triazine (e.g., 1,2,4-triazine, 1,3,5-triazine), and tetrazine. In some embodiments, both rings of a polycyclic heteroaryl group are aromatic. Examples include indole, isoindole, indazole, benzoimidazole, benzotriazole, benzofuran, benzoxazole, benzoisoxazole, benzoxadiazole, benzothiophene, benzothiazole, benzoisothiazole, benzothiadiazole, 1H-pyrrolo[2,3-b]pyridine, 1H-pyrazolo[3,4- b]pyridine, 3H-imidazo[4,5-b]pyridine, 3H-[1,2,3]triazolo[4,5-b]pyridine, 1H-pyrrolo[3,2- b]pyridine, 1H-pyrazolo[4,3-b]pyridine, 1H-imidazo[4,5-b]pyridine, 1H-[1,2,3]triazolo[4,5- b]pyridine, 1H-pyrrolo[2,3-c]pyridine, 1H-pyrazolo[3,4-c]pyridine, 3H-imidazo[4,5- c]pyridine, 3H-[1,2,3]triazolo[4,5-c]pyridine, 1H-pyrrolo[3,2-c]pyridine, 1H-pyrazolo[4,3- c]pyridine, 1H-imidazo[4,5-c]pyridine, 1H-[1,2,3]triazolo[4,5-c]pyridine, furo[2,3- b]pyridine, oxazolo[5,4-b]pyridine, isoxazolo[5,4-b]pyridine, [1,2,3]oxadiazolo[5,4- b]pyridine, furo[3,2-b]pyridine, oxazolo[4,5-b]pyridine, isoxazolo[4,5-b]pyridine, [1,2,3]oxadiazolo[4,5-b]pyridine, furo[2,3-c]pyridine, oxazolo[5,4-c]pyridine, isoxazolo[5,4-c]pyridine, [1,2,3]oxadiazolo[5,4-c]pyridine, furo[3,2-c]pyridine, oxazolo[4,5- c]pyridine, isoxazolo[4,5-c]pyridine, [1,2,3]oxadiazolo[4,5-c]pyridine, thieno[2,3- b]pyridine, thiazolo[5,4-b]pyridine, isothiazolo[5,4-b]pyridine, [1,2,3]thiadiazolo[5,4- b]pyridine, thieno[3,2-b]pyridine, thiazolo[4,5-b]pyridine, isothiazolo[4,5-b]pyridine, [1,2,3]thiadiazolo[4,5-b]pyridine, thieno[2,3-c]pyridine, thiazolo[5,4-c]pyridine, isothiazolo[5,4-c]pyridine, [1,2,3]thiadiazolo[5,4-c]pyridine, thieno[3,2-c]pyridine, thiazolo[4,5-c]pyridine, isothiazolo[4,5-c]pyridine, [1,2,3]thiadiazolo[4,5-c]pyridine, quinoline, isoquinoline, cinnoline, quinazoline, quinoxaline, phthalazine, naphthyridine (e.g., 1,8-naphthyridine, 1,7-naphthyridine, 1,6-naphthyridine, 1,5-naphthyridine, 2, 7- naphthyridine, 2,6-naphthyridine), imidazo[1,2-a]pyridine, 1H-pyrazolo[3,4-d]thiazole, 1H- pyrazolo[4,3-d]thiazole, and imidazo[2,1-b]thiazole. The term “hydrocarbyl” as used herein, refers to a monovalent, divalent, or multivalent group, comprising hydrogen and carbon atoms, such as a major proportion (i.e., more than 50 %) of hydrogen and carbon atoms. The hydrocarbyl group may comprise aromatic, saturated aliphatic or unsaturated aliphatic groups. The hydrocarbyl group may be entirely aliphatic or a combination of aliphatic, alicyclic, and aromatic portions. The hydrocarbyl group may include a branched aliphatic chain which is substituted by one or more aromatic groups. Examples of hydrocarbyl groups therefore include acyclic groups, as well as groups that combine one or more acyclic portions and one or more cyclic portions, which may be selected from carbocyclic, aryl and heterocyclyl groups. The hydrocarbyl group includes monovalent groups and polyvalent groups as specified and may, for example, include one or more groups selected from alkyl, alkenyl, alkynyl, carbocyclyl (e.g. cycloalkyl or cycloalkenyl), aryl and heterocyclyl. The hydrocarbyl group may contain one or more heteroatoms, such as oxygen, nitrogen, sulphur, silicon or halogen which may be part of a functional group such as an alcohol, ether, carbonyl, ester, carboxylic acid, carbonate, amide, amine, carbamate, urea, thiol, thioether, thioester, thioacid, thioamide, sulfone, sulfoxide, silane organic halide or heterocycle, the hydrocarbyl linker may contain any combination of the above insofar as it is chemically stable. Furthermore, in some embodiments, halogens may entirely replace the hydrogen component of the hydrocarbyl group (i.e. the carbon-bonded hydrogens) to give the corresponding halo-substituted analogue. A monovalent hydrocarbyl group is typically described as a group, whereas a multivalent hydrocarbyl group (such as a divalent or trivalent hydrocarbyl group) is typically described as a linker. Examples include ethylene glycol and polyethylene glycol (PEG) linkers. The term “molecular weight” (MW) as used herein has its normal meaning in the art. In the context of polymers described herein, the term “molecular weight” refers to the number average molecular weight (Mn), i.e. the total weight of polymer divided by the number of polymer molecules. The molecular weight of a molecule or nanoparticle composition may be presented in units of Da (Daltons). Molecular weight may be measured by size exclusion chromatography methods as will be known by those skilled in the relevant art. For example, size exclusion chromatography may be coupled with differential viscometry detection to determine molecular weight. The term “branched” refers to polymers containing branches that are composed of the same units that make up the linear portion of the main chain. As used herein, the term “hyperbranched” refers to polymers containing branches that are composed of the units that make up the linear portion of the main chain as well as further branch points (e.g., radicals of Formula (D) and Formula (D-I), also referred to as “dendritic units”). Hyperbranched dendritic polymers contain randomly distributed dendritic units and offer a large chemical space for investigation as they can be synthesized with a wide range of monomers using one-pot reaction conditions. Linear segments can be combined with hyperbranched segments to alter the degree of branching (DB), thereby altering properties such as solubility, viscosity, and efficacy as a transfection reagent. The terms “Degree of branching” and “DB” can be defined as the ratio of dendritic units (radicals of Formula (D) and Formula (D-I)) to linear units (radicals of Formulae (A), (B), (B-I), and (C)). DB can be calculated using the equation: DB=(D+T) / (D+T+L), where D is number of dendritic units, T is the number of terminal units (radical of Formula (A)) and L is number of linear units (radicals of Formulae (B), (B-I), and (C)). (See also, Hawker & Fretchet 1991 J. Am. Chem. Soc.113(12)). DB can be controlled as a function of the stoichiometry of Formula (C) to Formula (D) or Formula (D-I). For example, higher DB is obtained by using a molar excess of the monomer corresponding to Formula (C), relative to the monomer corresponding to Formula (D) or (D-I). Linear polymers (DB = 0) are obtained by omitting the monomer corresponding to Formula (D) or (D-I). DB also correlates directly with an increase in terminal peptide groups. Increased density of peptide groups in the peptide modified polymer may influence polymer efficacy as a transfection reagent at various stages during the formulation and transfection process, for example, during nanoparticle formulation when the cationic polymer protects nucleic acid cargo through electrostatic condensation to prevent degradation by nucleases. Peptide groups may comprise primary amines that may advantageously become protonated under physiological pH. The term “nanoparticle” as used herein refers to a particle having a z-average mean diameter from 1 to 1000 nm, as measured by dynamic light scattering. The term "NP" as used herein refers to a nanoparticle. The term "z-average" as used herein refers to the z-average mean diameter, i.e. the intensity weighted mean hydrodynamic size of the ensemble collection of particles of a sample, as determined by dynamic light scattering. References to "z-average" and "z-average mean diameter" as used herein refer to z-average mean diameter as determined by dynamic light scattering. Z-average mean diameter was determined by DLS analysis of aqueous suspensions performed at 25 °C using a Malvern Zetasizer Ultra instrument. Samples were prepared by diluting nanoparticle dispersions 1 in 10 with the appropriate dispersant (1 mL). Measurements were performed using polystyrene cuvettes at 25 °C, measuring the scattered light at an angle of 173°. The term “PBAE” as used herein refers to poly (beta-amino esters). The term "optional" or "optionally" as used herein means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where the event or circumstance occurs and instances in which it does not. For example, "optionally substituted alkyl" encompasses both "alkyl" and "substituted alkyl," as defined herein. It will be understood by those skilled in the art, with respect to any group containing one or more substituents, that such groups are not intended to introduce any substitution or substitution patterns that are sterically impractical, synthetically non- feasible, and / or inherently unstable. It will also be understood that where a group or moiety is optionally substituted, the invention includes both embodiments in which the group or moiety is substituted and embodiments in which the group or moiety is unsubstituted. The term “PEG” as used herein refers to polyethylene glycol. The terms "patient," "individual," and "subject" as used herein refer to an animal, such as a mammal, bird, or fish. In some embodiments, the patient or subject is a mammal. Mammals include, for example, mice, rats, dogs, cats, pigs, sheep, horses, cows and humans. In some embodiments, the patient or subject is a human, for example a human that has been or will be the object of treatment, observation or experiment. In some preferred embodiments, the patient or subject is a paediatric human, preferably a paediatric human that has been or will be the object of treatment, observation or experiment. The compounds, compositions and methods described herein can be useful in both human therapy and veterinary applications. The term "pharmaceutically acceptable carrier" or "pharmaceutically acceptable excipient" as used herein includes any and all solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption delaying agents, and the like. The use of such media and agents for pharmaceutically active substances is well known in the art. Except insofar as any conventional media or agent is incompatible with the active ingredient, its use in pharmaceutical compositions is contemplated. Supplementary active ingredients can also be incorporated into the pharmaceutical compositions. The term “prodrug” as used herein means a pharmacological derivative of a parent drug molecule that requires biotransformation, either spontaneous or enzymatic, within the organism to release the active drug. For example, prodrugs are variations or derivatives of compounds that have groups cleavable under certain metabolic conditions, which when cleaved, become the pharmacologically active form. Such prodrugs then are pharmaceutically active in vivo when they undergo solvolysis under physiological conditions or undergo enzymatic degradation. Prodrug compounds herein may be called single, double, triple, etc., depending on the number of biotransformation steps required to release the active drug within the organism, and the number of functionalities present in a precursor-type form. Prodrug forms often offer advantages of solubility, tissue compatibility, or delayed release in the mammalian organism. Prodrugs commonly known in the art include well-known acid derivatives, such as, for example, esters prepared by reaction of acid compounds with a suitable alcohol, amides prepared by reaction of acid compounds with an amine, and basic groups reacted to form an acylated base derivative. Other prodrug derivatives may be combined with other features disclosed herein to enhance bioavailability. As such, those of skill in the art will appreciate that certain of the presently disclosed compounds having, for example, free amino or hydroxy groups can be converted into prodrugs. Prodrugs include compounds having an amino acid residue, or a polypeptide chain of two or more (e.g. two, three or four) amino acid residues which are covalently joined through peptide bonds to free amino, hydroxy or carboxylic acid groups of the presently disclosed compounds. The amino acid residues include the 20 naturally occurring amino acids commonly designated by three letter symbols and also include 4-hydroxyproline, hydroxylysine, demosine, isodemosine, 3-methylhistidine, norvalin, beta-alanine, gamma-aminobutyric acid, citrulline, homocysteine, homoserine, ornithine and methionine sulfone. Prodrugs also include compounds having a carbonate, carbamate, amide or alkyl ester moiety covalently bonded to any of the above substituents disclosed herein. The term “treatment” (and related terms, such as "treat", "treated", "treating") as used herein includes one or more of: inhibiting a disease or disorder; slowing or arresting the development of clinical symptoms of a disease or disorder; and / or relieving a disease or disorder (i.e., causing relief from or regression of clinical symptoms). The term covers both complete and partial reduction of the condition or disorder, and complete or partial reduction of clinical symptoms of a disease or disorder. Thus, nanoparticle compositions comprising a polynucleotide described and / or disclosed herein may prevent an existing disease or disorder from worsening, assist in the management of the disease or disorder, or reduce or eliminate the disease or disorder. As used in the specification and claims, the singular form “a”, “an” and “the” include plural references unless the context clearly dictates otherwise. For example, the term “a nanoparticle” includes a plurality of nanoparticles, including mixtures thereof. Unless specifically stated or obvious from context, as used herein, the term “or” is understood to be inclusive. The term “including” is used herein to mean, and is used interchangeably with, the phrase “including but not limited to”. Peptide modified polymers The peptide modified polymers of the present invention are poly(beta amino ester) (PBAE) polymers that are end capped with peptide moieties. The peptide modified polymers may be linear i.e. non-branched, or they may be branched. The structure of the peptide modified polymers may be changed to optimise their physical properties such as solubility, viscosity, and efficacy as transfection agents. Such changes to the structure of the peptide modified polymers may, for example, include branching, or incorporate hydrophobic or hydrophilic (e.g. PEG) groups. Linear peptide modified polymers In one aspect, the present invention provides a peptide modified polymer for nucleic acid delivery comprising: a radical of Formula (A) having the structure: ; a diradical of Formula (B) having the structure: a diradical of Formula (C) having the structure: wherein: each radical of Formula (A) has one point of attachment to a diradical of Formula (B); each diradical of Formula (B) has two points of attachment to separate radicals independently selected from: Formula (A) and Formula (C); each diradical of Formula (C) has two points of attachment, each to a separate diradical of Formula (B); wherein each X is independently selected from: -O-, -S-, and -NRw-; wherein each Y is independently selected from: =O, =S, and -OH; wherein L1is a hydrocarbyl linker comprising 1 to 500 carbon atoms; wherein R1comprises a peptide radical; wherein each R2is independently selected from: -H, -C1to C20alkyl; -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, and -C2to C20alkynyl; wherein said -C1to C20alkyl; -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, or -C2to C20alkynyl group is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -OR4, -NH2, -NHR4, -NR42, -C(O)OH, -C(O)OR4, -C(O)NH2, -C(O)NHR4, -C(O)NR42, - O(CO)H, -O(CO)R4, -NH(CO)H, -NH(CO)R4, -NR4(CO)H, -NR4(CO)R4, -SH, -SR4, -SO2H, -SO2R4, -SO3R4, -SO3H, -SiR43, -NO2, -CN, -F, -Cl, -Br, -I, -C6to C14aryl optionally substituted with one or more R5groups, and -C2to C9heteroaryl optionally substituted with one or more R5groups; wherein each R3is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3 to C20 cycloalkyl, -C3 to C20 heterocycloalkyl, -C2 to C20 alkenyl, -C2 to C20 alkynyl, -C1to C20alkyloxy, -C1to C20alkylamino, -C6to C14aryl optionally substituted with one or more R6groups, and -C2to C9heteroaryl optionally substituted with one or more R6groups; wherein said -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyloxy, or -C1to C20alkylamino group is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl-C3to C20cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C1to C20alkyloxy, -C1to C20alkylamino, -OH, -OR7, -NH2, -NHR7, - NR72, -C(O)OH, -C(O)OR7, -C(O)NH2, -C(O)NHR7, -C(O)NR72, -O(CO)H, -O(CO)R7, - NH(CO)H, -NH(CO)R7, -NR7(CO)H, -NR7(CO)R7, -SH, -SR7, -SO2H, -SO2R7, -SO3R7, - SO3H, -SiR73, -NO2, -CN, -F, -Cl, -Br, -I, -C6to C14aryl optionally substituted with one or more R8groups, and -C2to C9heteroaryl optionally substituted with one or more R8groups; wherein each R4is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl- C3to C10cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C1to C20alkoxy, -C1to C20alkylamino, -C6to C14aryl, and -C2to C9heteroaryl; wherein each R5is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I; wherein each R6is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I; wherein each R7is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl- C3 to C10 cycloalkyl, -C1 to C20 alkyl-C3 to C10 heterocycloalkyl, -C1 to C20 alkoxy, -C1 to C20alkylamino, -C6to C14aryl, and -C2to C9heteroaryl; wherein each R8is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I; and wherein each Rwis independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3 to C20 cycloalkyl, and -C2 to C20 alkenyl. In embodiments, R1is a peptide radical. Accordingly, in embodiments, the present invention provides a peptide modified polymer for nucleic acid delivery comprising: a radical of Formula (A) having the structure: ; a diradical of Formula (B) having the structure: a diradical of Formula (C) having the structure: wherein: each radical of Formula (A) has one point of attachment to a diradical of Formula (B); each diradical of Formula (B) has two points of attachment to separate radicals independently selected from: Formula (A) and Formula (C); each diradical of Formula (C) has two points of attachment, each to a separate diradical of Formula (B); wherein each X is independently selected from: -O-, -S-, and -NRw-; wherein each Y is independently selected from: =O, =S, and -OH; wherein L1is a hydrocarbyl linker comprising 1 to 500 carbon atoms; wherein R1is a peptide radical; wherein each R2is independently selected from: -H, -C1to C20alkyl; -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, and -C2to C20alkynyl; wherein said -C1to C20alkyl; -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20 heterocycloalkyl, -C2 to C20 alkenyl, or -C2 to C20 alkynyl group is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -OR4, -NH2, -NHR4, -NR42, -C(O)OH, -C(O)OR4, -C(O)NH2, -C(O)NHR4, -C(O)NR42, - O(CO)H, -O(CO)R4, -NH(CO)H, -NH(CO)R4, -NR4(CO)H, -NR4(CO)R4, -SH, -SR4, -SO2H, -SO2R4, -SO3R4, -SO3H, -SiR43, -NO2, -CN, -F, -Cl, -Br, -I, -C6to C14aryl optionally substituted with one or more R5groups, and -C2 to C9 heteroaryl optionally substituted with one or more R5groups; wherein each R3is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyloxy, -C1to C20alkylamino, -C6to C14aryl optionally substituted with one or more R6groups, and -C2to C9heteroaryl optionally substituted with one or more R6groups; wherein said -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyloxy, or -C1to C20alkylamino group is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl-C3to C20cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C1to C20alkyloxy, -C1to C20alkylamino, -OH, -OR7, -NH2, -NHR7, - NR72, -C(O)OH, -C(O)OR7, -C(O)NH2, -C(O)NHR7, -C(O)NR72, -O(CO)H, -O(CO)R7, - NH(CO)H, -NH(CO)R7, -NR7(CO)H, -NR7(CO)R7, -SH, -SR7, -SO2H, -SO2R7, -SO3R7, - SO3H, -SiR73, -NO2, -CN, -F, -Cl, -Br, -I, -C6to C14aryl optionally substituted with one or more R8groups, and -C2to C9heteroaryl optionally substituted with one or more R8groups; wherein each R4is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl- C3to C10cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C1to C20alkoxy, -C1to C20alkylamino, -C6to C14aryl, and -C2to C9heteroaryl; wherein each R5is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I; wherein each R6is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I; wherein each R7is independently selected from: -C1 to C20 alkyl, -C1 to C20 haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl- C3to C10cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C1to C20alkoxy, -C1to C20alkylamino, -C6to C14aryl, and -C2to C9heteroaryl; wherein each R8is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20 cycloalkyl, -C2 to C20 alkenyl, -C2 to C20 alkynyl, -OH, -NH2, -OC1 to C20 alkyl, -NHC1 to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I; and wherein each Rwis independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, and -C2to C20alkenyl. Accordingly, the peptide modified polymers of the present invention comprise radicals of Formulae (A), (B), and (C) in various orders, molar percentages, and arrangements. Significantly, by changing the molar percentages of these various constituent radicals, the physical properties of the peptide modified polymers may be changed. For the sake of clarity, when it is stated that e.g. “each radical of Formula (A) has one point of attachment to a diradical of Formula (B)”, it is to be understood that a radical of Formula (A) and a diradical of Formula (B) come together to form a covalent bond. The fragment that corresponds to the original diradical of Formula (B) still has a second radical that may form a bond with another species selected from: Formula (A) and Formula (C). In embodiments, the radical of Formula (A) comprises a heteroatom radical. By this it is meant that the radical is e.g. a nitrogen- or oxygen-radical. The peptide modified polymer comprises at least one radical of Formula (C). Accordingly, the peptide modified polymer does not have the structure: . In other words, the peptide modified polymer does not have the structure [Formula (A)]-[Formula (B)]-[Formula (A)]. Branched peptide modified polymers Advantageously, the peptide modified polymers of the present invention may be branched. In particular, the extent to which the peptide modified polymers are branched may be changed in order to optimise their physical properties such as solubility, viscosity, and efficacy as transfection agents. In embodiments the present invention provides a peptide modified polymer for nucleic acid delivery additionally comprising: a radical species of Formula (D) having the structure: wherein: each radical species of Formula (D) has at least two points of attachment to separate diradicals of Formula (B) and each * independently denotes a point of attachment to (i) a separate diradical of Formula (B), or (ii) a substituent R9; wherein L2is a hydrocarbyl linker comprising 1 to 500 carbon atoms; wherein each R9is independently selected from: -H, -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, and -C2to C20alkynyl, wherein said -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, or -C2to C20alkynyl is optionally substituted with one or more group independently selected from: -C1 to C20 alkyl, -C1 to C20 haloalkyl, -C3 to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, - OR10, -NH2, -NHR10, -NR102, -C(O)OR10, -C(O)NH2, -C(O)NHR10, -C(O)NR102, -O(CO)H, - O(CO)R10, -NH(CO)H, -NH(CO)R10, -NR10(CO)H, -NR10(CO)R10, -SR10, -NO2, -CN, -F, - Cl, -Br, -I, -C6to C14aryl optionally substituted with one or more R11groups, and -C2to C9heteroaryl optionally substituted with one or more R11groups; wherein each R10is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl- C3to C10cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C1to C20alkoxy, -C1to C20alkylamino, -C6to C14aryl, and -C2to C9heteroaryl; and wherein each R11is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3 to C20 cycloalkyl, -C2 to C20 alkenyl, -C2 to C20 alkynyl, -OH, -NH2, -OC1 to C20alkyl, -NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I. Accordingly, the peptide modified polymers of the present invention comprise radicals of Formulae (A), (B), (C), and (D) in various orders, molar percentages, and arrangements. Significantly, by changing the molar percentages of these various constituent radicals, the physical properties of the peptide modified polymers may be changed. Peptide modified polymer formulae In this specification, embodiments defining the nature of various substituent groups are presented. The order in which they are presented is simply for ease of reading, and merely because they are presented in close proximity to a certain formula, this is not to be interpreted as being limiting in any way. Formula (B) Formula (B) is a diradical comprising a hydrocarbyl linker. Diradicals of Formula (B) have two points of attachment to separate radicals independently selected from: Formula (A) and Formula (C). A diradical of Formula (B) has the structure: wherein R2, X, and L1are as defined herein. In embodiments, each X is independently selected from: -O-, -S-, and -NRw-. In embodiments, each X is -NRw-. In embodiments, each Rwis independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, and -C2to C20alkenyl. In embodiments, each Rwis independently selected from: -C1to C20alkyl and -C3to C20cycloalkyl. In embodiments, each Rwis independently selected from: -C1to C8alkyl and -C3to C8cycloalkyl. In embodiments, each Rwis independently selected from: -C1to C8alkyl. In embodiments, each X is -S-. In embodiments, each X is -O-. In embodiments, each Y is independently selected from: =O, =S, and -OH. In embodiments, each Y is =S. In embodiments, each Y is =O. In embodiments, each Y is -OH. In embodiments, each X is -S-, and each Y is =O. In embodiments, each X is -S-, and each Y is =S. In embodiments, each X is -S-, and each Y is -OH. In embodiments, each X is -NRw-, and each Y is =O. In embodiments, each X is - NRw-, and each Y is =S. In embodiments, each X is -NRw-, and each Y is -OH. In embodiments, each X is -O-, and each Y is =O. In embodiments, each X is -O-, and each Y is =S. In embodiments, each X is -O-, and each Y is -OH. In embodiments wherein each X is -O-, and each Y is =O, the diradical of Formula (B) is defined by Formula (B-I): wherein each R2and L1are as defined herein. In embodiments, each R2is independently selected from: -H, -C1to C20alkyl; -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, and - C2to C20alkynyl; wherein said -C1to C20alkyl; -C1to C20haloalkyl, -C3to C20cycloalkyl, - C3to C20heterocycloalkyl, -C2to C20alkenyl, or -C2to C20alkynyl group is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -OR4, -NH2, -NHR4, -NR42, -C(O)OH, -C(O)OR4, -C(O)NH2, -C(O)NHR4, -C(O)NR42, -O(CO)H, -O(CO)R4, -NH(CO)H, -NH(CO)R4, -NR4(CO)H, -NR4(CO)R4, -SH, -SR4, -SO2H, -SO2R4, -SO3R4, -SO3H, -SiR43, -NO2, -CN, -F, -Cl, -Br, -I, -C6to C14aryl optionally substituted with one or more R5groups, and -C2to C9heteroaryl optionally substituted with one or more R5groups. In embodiments, each R2is independently selected from: -H, -C1to C20alkyl; -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, and -C2to C20alkynyl; wherein said -C1to C20alkyl; -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, or -C2to C20alkynyl group is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -OR4, -NH2, -NHR4, -NR42, -C(O)OR4, -C(O)NH2, -C(O)NHR4, -C(O)NR42, -O(CO)R4, -NH(CO)R4, -NR4(CO)R4, -SH, -SR4, -SO2R4, -SO3R4, -SiR43, -NO2, -CN, -F, -Cl, -Br, -I, -C6to C14aryl optionally substituted with one or more R5groups, and -C2to C9heteroaryl optionally substituted with one or more R5groups. In embodiments, each R2is independently selected from: -H, -C1to C20alkyl; -C1to C20haloalkyl, and -C2to C20alkenyl; wherein said -C1to C20alkyl; -C1to C20haloalkyl, or -C2to C20alkenyl is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -OH, -OR4, -NH2, -NHR4, -NR42, -C(O)OR4, -C(O)NH2, -C(O)NHR4, -C(O)NR42, -O(CO)R4, -NH(CO)R4, -NR4(CO)R4, -SH, -SR4, -NO2, -CN, -F, - Cl, -Br, -I, -C6to C14aryl optionally substituted with one or more R5groups, and -C2to C9heteroaryl optionally substituted with one or more R5groups. In embodiments, each R2is independently selected from: -H, -C1to C20alkyl; -C1to C20haloalkyl, and -C2to C20alkenyl; wherein said -C1to C20alkyl; -C1to C20haloalkyl, or -C2 to C20 alkenyl is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C2to C20alkenyl, -OH, -OR4, -NH2, -NHR4, -NR42, - C(O)OR4, -C(O)NH2, -C(O)NHR4, -C(O)NR42, -O(CO)R4, -NH(CO)R4, -NR4(CO)R4, -SH, - C6to C14aryl optionally substituted with one or more R5groups, and -C2to C9heteroaryl optionally substituted with one or more R5groups. In embodiments, each R2is independently selected from: -H and -C1to C20alkyl; wherein said -C1 to C20 alkyl is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C2to C20alkenyl, -OH, -OR4, -NH2, -NHR4, -NR42, - C(O)OR4, -C(O)NH2, -C(O)NHR4, -C(O)NR42, -O(CO)R4, -NH(CO)R4, -NR4(CO)R4, -SH, - C6to C14aryl optionally substituted with one or more R5groups, and -C2to C9heteroaryl optionally substituted with one or more R5groups. In embodiments, each R2is independently selected from: -H and -C1to C20alkyl; wherein said -C1to C20alkyl is optionally substituted with one or more group independently selected from: -C1to C8alkyl, -C2to C8alkenyl, -OR4, -NR42, -C(O)OR4, -C(O)NR42, - O(CO)R4, -NH(CO)R4, -NR4(CO)R4, -C6to C14aryl optionally substituted with one or more R5groups, and -C2to C9heteroaryl optionally substituted with one or more R5groups. In embodiments, each R2is independently selected from: -H and -C1to C8alkyl; wherein said -C1to C8alkyl is optionally substituted with one or more group independently selected from: -C1to C8alkyl, -C2to C8alkenyl, -OR4, -NR42, -C(O)OR4, -C(O)NR42, - O(CO)R4, -NH(CO)R4, -NR4(CO)R4, -C6to C14aryl optionally substituted with one or more R5groups, and -C2to C9heteroaryl optionally substituted with one or more R5groups. In embodiments, each R2is independently selected from: -H and -C1to C8alkyl; wherein said -C1to C8alkyl is optionally substituted with one or more group independently selected from: -C1to C8alkyl, -C2to C8alkenyl, -OR4, -NR42, -C(O)OR4, -C(O)NR42, - O(CO)R4, -NH(CO)R4, and -NR4(CO)R4. In embodiments, each R2is independently selected from: -H and -C1to C20alkyl. In embodiments, each R2is independently selected from: -H and -C1to C8alkyl. In embodiments, each R2is independently selected from -C1to C8alkyl. In embodiments, each R2is -H. In embodiments, each R4is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl-C3to C10cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C1to C20alkoxy, -C1to C20alkylamino, -C6to C14aryl, and -C2to C9heteroaryl. In embodiments, each R4is independently selected from: -C1 to C20 alkyl, -C1 to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl-C3to C10cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C6to C14aryl, and -C2to C9heteroaryl. In embodiments, each R4is independently selected from: -C1to C20alkyl, -C1to C20 haloalkyl, -C3 to C20 cycloalkyl, -C3 to C20 heterocycloalkyl, -C2 to C20 alkenyl, -C6 to C14aryl, and -C2to C9heteroaryl. In embodiments, each R4is independently selected from: -C1to C20alkyl, C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C6to C14aryl, and -C2to C9heteroaryl. In embodiments, each R4is independently selected from: -C1to C20alkyl and -C2to C20alkenyl. In embodiments, each R4is independently selected from -C1to C20alkyl. In embodiments, each R4is independently selected from -C1to C8alkyl. In embodiments, each R5is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I. In embodiments, each R5is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -F, -Cl, -Br, and -I. In embodiments, each R5is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -OH, -NH2, -OC1to C20alkyl, -F, -Cl, -Br, and -I. In embodiments, each R5is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -OC1to C20alkyl, -F, -Cl, -Br, and -I. In embodiments, each R5is independently selected from: -C1to C20alkyl, -C3to C20cycloalkyl, -OC1to C20alkyl, -F, -Cl, -Br, and -I. In embodiments, each R5is independently selected from: -C1to C8alkyl, -C3to C8cycloalkyl, -OC1to C8alkyl, -F, -Cl, -Br, and -I. In embodiments, each R5is independently selected from: -C1to C8alkyl, -C3to C8cycloalkyl, -OC1to C8alkyl, -F, -Cl, -Br, and -I. In embodiments, each R5is independently selected from -C1to C8alkyl. In embodiments, L1is selected from: optionally substituted aliphatic (e.g. alkylene, alkenylene, or alkynylene), optionally substituted heteroaliphatic (e.g. heteroalkylene), optionally substituted carbocyclylene, optionally substituted heterocyclylene, optionally substituted arylene, optionally substituted heteroarylene, and a combination thereof. In embodiments, L1is selected from: substituted aliphatic, unsubstituted aliphatic, substituted heteroaliphatic, unsubstituted heteroaliphatic, substituted arylene, unsubstituted arylene, substituted heteroarylene, unsubstituted heteroarylene, and a combination thereof. In embodiments, L1is optionally substituted aliphatic (e.g. alkylene, alkenylene, or alkynylene). In embodiments, L1is optionally substituted alkylene. In embodiments, L1is alkylene. In embodiments, L1is alkylene wherein the carbon chain length is from 1 to 500, 1 to 400, 1 to 300, 1 to 200, 1 to 190, 1 to 180, 1 to 170, 1 to 160, 1 to 150, 1 to 140, 1 to 130, 1 to 120, 1 to 110, 1 to 100, 1 to 95, 1 to 90, 1 to 85, 1 to 80, 1 to 75, 1 to 70, 1 to 65, 1 to 60, 1 to 55, 1 to 50, 1 to 45, 1 to 40, 1 to 35, 1 to 30, 1 to 25, 1 to 20, 1 to 15, 1 to 10, or 1 to 5 carbon atoms. In embodiments, L1is –(CH2)m- wherein m is from 1 to 500, 1 to 400, 1 to 300, 1 to 200, 1 to 190, 1 to 180, 1 to 170, 1 to 160, 1 to 150, 1 to 140, 1 to 130, 1 to 120, 1 to 110, 1 to 100, 1 to 95, 1 to 90, 1 to 85, 1 to 80, 1 to 75, 1 to 70, 1 to 65, 1 to 60, 1 to 55, 1 to 50, 1 to 45, 1 to 40, 1 to 35, 1 to 30, 1 to 25, 1 to 20, 1 to 15, 1 to 10, or 1 to 5. In embodiments, L1is selected from: , , and wherein each R2is -H. In embodiments, L1is a hydrophobic linker. In embodiments, L1is a hydrophilic linker. Examples of hydrophilic linkers include heteroalkylene and PEG linkers. It can be advantageous to use hydrophilic linkers for L1in the peptide modified polymers of the invention because this can result in increased aqueous solubility. A person of ordinary skill in the art will appreciate that this is an important property in the context of in vivo delivery of polynucleotides to cells. In embodiments, L1is optionally substituted heteroalkylene. In embodiments, L1is heteroalkylene. In embodiments, L1is heteroalkylene and R2is H. In embodiments, L1is heteroalkylene wherein the carbon chain length is from 1 to 500, 1 to 400, 1 to 300, 1 to 200, 1 to 190, 1 to 180, 1 to 170, 1 to 160, 1 to 150, 1 to 140, 1 to 130, 1 to 120, 1 to 110, 1 to 100, 1 to 95, 1 to 90, 1 to 85, 1 to 80, 1 to 75, 1 to 70, 1 to 65, 1 to 60, 1 to 55, 1 to 50, 1 to 45, 1 to 40, 1 to 35, 1 to 30, 1 to 25, 1 to 20, 1 to 15, 1 to 10, or 1 to 5 carbon atoms. In embodiments, L1is wherein n is an integer selected from 0 to 250, for example n is 0 or 2. In embodiments, n is an integer selected from 0 to 250, 0 to 225, 0 to 200, 0 to 190, 0 to 180, 0 to 170, 0 to 160, 0 to 150, 0 to 140, 0 to 130, 0 to 120, 0 to 110, 0 to 100, 0 to 95, 0 to 90, 0 to 85, 0 to 80, 0 to 75, 0 to 70, 0 to 65, 0 to 60, 0 to 55, 0 to 50, 0 to 45, 0 to 40, 0 to 35, 0 to 30, 0 to 25, 0 to 20, 0 to 15, 0 to 10, or 0 to 5. In embodiments, n is 0. In embodiments, n is 2. In embodiments, n is 13. In embodiments, As one of ordinary skill in the art will appreciate, peptide modified polymers of the invention in which L1is a heteroalkylene chain such as will often be prepared from commercial sources such as polyethylene glycols in which there is a distribution of different chain lengths. Accordingly, it will be appreciated that n may vary, and in some cases it may be more appropriate to define the linker using the number average molecular weight (Mn), i.e. the total weight of polymer divided by the number of polymer molecules. In embodiments, the number average molecular weight (Mn) of L1is about 5000, about 4000, about 3000, about 2000, about 1000, about 950, about 900, about 850, about 800, about 750, about 700, about 650, about 600, about 550, about 500, about 450, about 400, about 350, about 300, about 250, or about 200. In embodiments, the number average molecular weight (Mn) of L1is about 558. In embodiments, L1is selected from: divalent -C2to C8hydrocarbyl and wherein each R12is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, - OC1to C20alkyl, -NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I; wherein each R13is independently selected from: -H, -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, and - C2to C20alkynyl; and wherein each Z is independently selected from an integer from 0 to 4. In embodiments, each R12is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I. In embodiments, each R12is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -F, -Cl, -Br, and -I. In embodiments, each R12is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -OH, -NH2, -OC1to C20alkyl, -F, -Cl, -Br, and -I. In embodiments, each R12is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -OC1to C20alkyl, -F, -Cl, -Br, and -I. In embodiments, each R12is independently selected from: -C1to C20alkyl, -C3to C20cycloalkyl, -OC1to C20alkyl, -F, -Cl, -Br, and -I. In embodiments, each R12is independently selected from: -C1to C8alkyl, -C3to C8cycloalkyl, -OC1to C8alkyl, -F, -Cl, -Br, and -I. In embodiments, each R12is independently selected from: -C1to C8alkyl, -C3to C8cycloalkyl, -OC1to C8alkyl, -F, -Cl, -Br, and -I. In embodiments, each R12is independently selected from -C1to C8alkyl. In embodiments, each R13is independently selected from: -H, -C1 to C20 alkyl, -C1 to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, and - C2to C20alkynyl. In embodiments, each R13is independently selected from: -H, -C1to C20alkyl, -C1to C20haloalkyl, -C2to C20alkenyl, and -C2to C20alkynyl. In embodiments, each R13is independently selected from: -H, -C1to C20alkyl, -C2to C20 alkenyl, and -C2 to C20 alkynyl. In embodiments, each R13is independently selected from: -H, -C1to C20alkyl, and -C2to C20alkenyl. In embodiments, each R13is independently selected from: -H and -C1to C20alkyl. In embodiments, each R13is independently selected from: -H and -C1to C8alkyl. In embodiments, each R13is independently selected from -C1to C8alkyl. In embodiments, each R13is H. In embodiments, Z is independently selected from an integer from 0 to 4. In embodiments, Z is independently selected from an integer from 0 to 4, e.g.0, 1, 2, 3, or 4. In embodiments, Z is independently selected from an integer from 0 to 3. In embodiments, Z is independently selected from an integer from 0 to 2. In embodiments, Z is independently selected from an integer from 0 and 1. In embodiments, Z is selected from an integer from 0 to 4, e.g.0, 1, 2, 3, or 4. In embodiments, Z is 0. In embodiments, Z is 1. In embodiments, Z is 2. In embodiments, Z is 3. In embodiments, Z is 4. Formula (C) Each diradical of Formula (C) has two points of attachment, each to a separate diradical of Formula (B). One of ordinary skill in the art will appreciate that this means that two separate covalent bonds are formed from a diradical of Formula (C) to two separate diradicals of Formula (B). For the avoidance of any doubt, a diradical of Formula (C) is not attached to a radical of Formula (A), nor a radical species of Formula (D). A diradical of Formula (C) has the structure: wherein R3is defined herein. In embodiments, each R3is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyloxy, -C1to C20alkylamino, -C6to C14aryl optionally substituted with one or more R6groups, and -C2 to C9 heteroaryl optionally substituted with one or more R6groups; wherein said -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, - C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyloxy, or -C1to C20alkylamino group is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyl-C6to C14aryl, -C1to C20 alkyl-C2 to C9 heteroaryl, -C1 to C20 alkyl-C3 to C20 cycloalkyl, -C1 to C20 alkyl-C3 to C10heterocycloalkyl, -C1to C20alkyloxy, -C1to C20alkylamino, -OH, -OR7, -NH2, -NHR7, - NR72, -C(O)OH, -C(O)OR7, -C(O)NH2, -C(O)NHR7, -C(O)NR72, -O(CO)H, -O(CO)R7, - NH(CO)H, -NH(CO)R7, -NR7(CO)H, -NR7(CO)R7, -SH, -SR7, -SO2H, -SO2R7, -SO3R7, - SO3H, -SiR73, -NO2, -CN, -F, -Cl, -Br, -I, -C6to C14aryl optionally substituted with one or more R8groups, and -C2to C9heteroaryl optionally substituted with one or more R8groups. In embodiments, each R3is independently selected from: -C1to C20alkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C1to C20alkyloxy, -C1to C20alkylamino, -C6to C14aryl optionally substituted with one or more R6groups, and -C2to C9heteroaryl optionally substituted with one or more R6groups; wherein said -C1to C20alkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C1to C20alkyloxy, or -C1to C20alkylamino group is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl-C3to C20cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C1to C20alkyloxy, -C1to C20alkylamino, -OH, -OR7, -NH2, -NHR7, -NR72, -C(O)OH, -C(O)OR7, - C(O)NH2, -C(O)NHR7, -C(O)NR72, -O(CO)H, -O(CO)R7, -NH(CO)H, -NH(CO)R7, - NR7(CO)H, -NR7(CO)R7, -SH, -SR7, -SO2H, -SO2R7, -SO3R7, -SO3H, -SiR73, -NO2, -CN, - F, -Cl, -Br, -I, -C6to C14aryl optionally substituted with one or more R8groups, and -C2to C9heteroaryl optionally substituted with one or more R8groups. In embodiments, each R3is independently selected from: -C1to C20alkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C1to C20alkyloxy, and -C1to C20alkylamino; wherein said -C1to C20alkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C1to C20alkyloxy, or -C1to C20alkylamino group is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, - C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl-C3to C20cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C1to C20alkyloxy, -C1to C20alkylamino, -OH, -OR7, - NH2, -NHR7, -NR72, -C(O)OH, -C(O)OR7, -C(O)NH2, -C(O)NHR7, -C(O)NR72, -O(CO)H, - O(CO)R7, -NH(CO)H, -NH(CO)R7, -NR7(CO)H, -NR7(CO)R7, -SH, -SR7, -SO2H, -SO2R7, - SO3R7, -SO3H, -SiR73, -NO2, -CN, -F, -Cl, -Br, -I, -C6to C14aryl optionally substituted with one or more R8groups, and -C2to C9heteroaryl optionally substituted with one or more R8groups. In embodiments, each R3is independently selected from: -C1to C20alkyl and -C3to C20 heterocycloalkyl; wherein said -C1 to C20 alkyl and -C3 to C20 heterocycloalkyl group is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C3to C20heterocycloalkyl, -OH, -OR7, -NH2, -NHR7, -NR72, -C(O)OH, -C(O)OR7, - C(O)NH2, -C(O)NHR7, -C(O)NR72, -O(CO)H, -O(CO)R7, -NH(CO)H, -NH(CO)R7, - NR7(CO)H, -NR7(CO)R7, -SH, -SR7, -SO2H, -SO2R7, -SO3R7, -SO3H, -SiR73, -NO2, -CN, - F, -Cl, -Br, -I, -C6to C14aryl optionally substituted with one or more R8groups, and -C2to C9heteroaryl optionally substituted with one or more R8groups. In embodiments, each R3is independently selected from: -C1to C20alkyl and -C3to C20heterocycloalkyl; wherein said -C1to C20alkyl and -C3to C20heterocycloalkyl group is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C3to C20heterocycloalkyl, -OH, -OR7, -NH2, -NHR7, and -NR72. In embodiments, each R3is independently selected from: -C1to C20alkyl and -C3to C20heterocycloalkyl; wherein said -C1to C20alkyl and -C3to C20heterocycloalkyl group is optionally substituted with one or more group independently selected from: -OH. In embodiments, each R3is independently selected from: -C1to C8alkyl and -C3to C8heterocycloalkyl; wherein said -C1to C20alkyl and -C3to C20heterocycloalkyl group is optionally substituted with one or more group independently selected from: -OH. In embodiments, each R3is independently selected from: -C1to C8alkyl; wherein said -C1to C20alkyl group is optionally substituted with one or more group independently selected from: -OH. In embodiments, each R3is independently selected from: -C3to C8heterocycloalkyl. In embodiments, R3 is selected from: , In embodiments, each R6is independently selected from: -C1 to C20 alkyl, -C1 to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I. In embodiments, each R6is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -F, -Cl, -Br, and -I. In embodiments, each R6is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -OH, -NH2, -OC1to C20alkyl, -F, -Cl, -Br, and -I. In embodiments, each R6is independently selected from: -C1to C20alkyl, -C1to C20 haloalkyl, -C3 to C20 cycloalkyl, -OC1 to C20 alkyl, -F, -Cl, -Br, and -I. In embodiments, each R6is independently selected from: -C1to C20alkyl, -C3to C20cycloalkyl, -OC1to C20alkyl, -F, -Cl, -Br, and -I. In embodiments, each R6is independently selected from: -C1to C8alkyl, -C3to C8cycloalkyl, -OC1to C8alkyl, -F, -Cl, -Br, and -I. In embodiments, each R6is independently selected from: -C1to C8alkyl, -C3to C8cycloalkyl, -OC1to C8alkyl, -F, -Cl, -Br, and -I. In embodiments, each R6is independently selected from -C1to C8alkyl. In embodiments, each R7is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl-C3to C10cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C1to C20alkoxy, -C1to C20alkylamino, -C6to C14aryl, and -C2to C9heteroaryl. In embodiments, each R7is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl-C3to C10cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C6to C14aryl, and -C2to C9heteroaryl. In embodiments, each R7is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C6to C14aryl, and -C2to C9heteroaryl. In embodiments, each R7is independently selected from: -C1 to C20 alkyl, C3 to C20 cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C6to C14aryl, and -C2to C9heteroaryl. In embodiments, each R7is independently selected from: -C1to C20alkyl and -C2to C20alkenyl. In embodiments, each R7is independently selected from -C1to C20alkyl. In embodiments, each R7is independently selected from -C1 to C8 alkyl. In embodiments, each R8is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I. In embodiments, each R8is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -F, -Cl, -Br, and -I. In embodiments, each R8is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -OH, -NH2, -OC1to C20alkyl, -F, -Cl, -Br, and -I. In embodiments, each R8is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -OC1to C20alkyl, -F, -Cl, -Br, and -I. In embodiments, each R8is independently selected from: -C1to C20alkyl, -C3to C20cycloalkyl, -OC1to C20alkyl, -F, -Cl, -Br, and -I. In embodiments, each R8is independently selected from: -C1to C8alkyl, -C3to C8cycloalkyl, -OC1to C8alkyl, -F, -Cl, -Br, and -I. In embodiments, each R8is independently selected from: -C1to C8alkyl, -C3to C8cycloalkyl, -OC1to C8alkyl, -F, -Cl, -Br, and -I. In embodiments, each R8is independently selected from -C1to C8alkyl. Formula (D-I) In embodiments, wherein each X is -O-, and each Y is =O, the radical species of Formula (D) is defined by Formula (D-I): wherein each R9and L2are as defined herein. In embodiments, each R9is independently selected from: -H, -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, and - C2to C20alkynyl. In embodiments, each R9is independently selected from: -H, -C1 to C20 alkyl, -C1 to C20haloalkyl, -C2to C20alkenyl, and -C2to C20alkynyl. In embodiments, each R9is independently selected from: -H, -C1to C8alkyl, -C1to C8haloalkyl, -C3to C8cycloalkyl, -C3to C8heterocycloalkyl, -C2to C8alkenyl, and -C2to C8alkynyl. In embodiments, each R9is independently selected from: -H, -C1to C20alkyl, -C2to C20 alkenyl, and -C2 to C20 alkynyl. In embodiments, each R9is independently selected from: -H, -C1to C20alkyl, and -C2to C20alkenyl. In embodiments, each R9is independently selected from: -H and -C1to C20alkyl. In embodiments, each R9is independently selected from: -H and -C1to C8alkyl. In embodiments, each R9is independently selected from -C1to C8alkyl. In embodiments, each R9is H. In other embodiments, each R9is not H. In embodiments, each R9is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, and -C2to C20alkynyl. In embodiments, each R9is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C2to C20alkenyl, and -C2to C20alkynyl. In embodiments, each R9is independently selected from: -C1to C20alkyl, -C2to C20alkenyl, and -C2to C20alkynyl. In embodiments, each R9is independently selected from: -C1to C20alkyl, and -C2to C20alkenyl. In embodiments, each R9is independently selected from -C1to C20alkyl. In embodiments, each R9is independently selected from -C1to C8alkyl. In embodiments, L2is selected from: optionally substituted aliphatic (e.g. alkylene, alkenylene, or alkynylene), optionally substituted heteroaliphatic (e.g. heteroalkylene), optionally substituted carbocyclylene, optionally substituted heterocyclylene, optionally substituted arylene, optionally substituted heteroarylene, and a combination thereof. In embodiments, L2is selected from: substituted aliphatic, unsubstituted aliphatic, substituted heteroaliphatic, unsubstituted heteroaliphatic, substituted arylene, unsubstituted arylene, substituted heteroarylene, unsubstituted heteroarylene, and a combination thereof. In embodiments, L2is optionally substituted aliphatic (e.g. alkylene, alkenylene, or alkynylene). In embodiments, L2is optionally substituted alkylene. In embodiments, L2is alkylene. In embodiments, L2is alkylene wherein the carbon chain length is from 1 to 500, 1 to 400, 1 to 300, 1 to 200, 1 to 190, 1 to 180, 1 to 170, 1 to 160, 1 to 150, 1 to 140, 1 to 130, 1 to 120, 1 to 110, 1 to 100, 1 to 95, 1 to 90, 1 to 85, 1 to 80, 1 to 75, 1 to 70, 1 to 65, 1 to 60, 1 to 55, 1 to 50, 1 to 45, 1 to 40, 1 to 35, 1 to 30, 1 to 25, 1 to 20, 1 to 15, 1 to 10, or 1 to 5 carbon atoms. In embodiments, L2is –(CH2)m- wherein m is from 1 to 500, 1 to 400, 1 to 300, 1 to 200, 1 to 190, 1 to 180, 1 to 170, 1 to 160, 1 to 150, 1 to 140, 1 to 130, 1 to 120, 1 to 110, 1 to 100, 1 to 95, 1 to 90, 1 to 85, 1 to 80, 1 to 75, 1 to 70, 1 to 65, 1 to 60, 1 to 55, 1 to 50, 1 to 45, 1 to 40, 1 to 35, 1 to 30, 1 to 25, 1 to 20, 1 to 15, 1 to 10, or 1 to 5. In embodiments, L2is selected from: , , , embodiments, L2 In embodiments, L2is divalent -C2to C8alkylene, for example . It is to be appreciated that the terms “alkylene” and “divalent alkylene” are used interchangeably herein. In embodiments, L2is a hydrophobic linker. In embodiments, L2is a hydrophilic linker. Examples of hydrophilic linkers include heteroalkylene and PEG linkers. It can be advantageous to use hydrophilic linkers for L2in the peptide modified polymers of the invention because this can result in increased aqueous solubility. A person of ordinary skill in the art will appreciate that this is an important property in the context of in vivo delivery of polynucleotides to cells. In embodiments, L2is optionally substituted heteroalkylene. In embodiments, L2is heteroalkylene. In embodiments, L2is heteroalkylene and R9is not H. In embodiments, L2is heteroalkylene wherein the chain length is from 1 to 500, 1 to 400, 1 to 300, 1 to 200, 1 to 190, 1 to 180, 1 to 170, 1 to 160, 1 to 150, 1 to 140, 1 to 130, 1 to 120, 1 to 110, 1 to 100, 1 to 95, 1 to 90, 1 to 85, 1 to 80, 1 to 75, 1 to 70, 1 to 65, 1 to 60, 1 to 55, 1 to 50, 1 to 45, 1 to 40, 1 to 35, 1 to 30, 1 to 25, 1 to 20, 1 to 15, 1 to 10, or 1 to 5 atoms. In embodiments, L2is ; wherein z is an integer selected from 0 to 250, for example z is 0 or 2. In embodiments, z is an integer selected from 0 to 250, 0 to 225, 0 to 200, 0 to 190, 0 to 180, 0 to 170, 0 to 160, 0 to 150, 0 to 140, 0 to 130, 0 to 120, 0 to 110, 0 to 100, 0 to 95, 0 to 90, 0 to 85, 0 to 80, 0 to 75, 0 to 70, 0 to 65, 0 to 60, 0 to 55, 0 to 50, 0 to 45, 0 to 40, 0 to 35, 0 to 30, 0 to 25, 0 to 20, 0 to 15, 0 to 10, or 0 to 5. As one of ordinary skill in the art will appreciate, peptide modified polymers of the invention in which L2is a heteroalkylene chain such as will often be prepared from commercial sources such as polyethylene glycols in which there is a distribution of different chain lengths. Accordingly, it will be appreciated that n may vary, and in some cases it may be more appropriate to define the linker using the number average molecular weight (Mn), i.e. the total weight of polymer divided by the number of polymer molecules. In embodiments, the number average molecular weight (Mn) of L2is about 5000, about 4000, about 3000, about 2000, about 1000, about 950, about 900, about 850, about 800, about 750, about 700, about 650, about 600, about 550, about 500, about 450, about 400, about 350, about 300, about 250, about 200, about 150, about 100, about 80, about 60, about 40, or about 20. In embodiments, each R9is methyl, and . In embodiments, each R10is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl-C3to C10cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C1to C20alkoxy, -C1to C20alkylamino, -C6to C14aryl, and -C2to C9heteroaryl. In embodiments, each R10is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl-C3to C10cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C6to C14aryl, and -C2to C9heteroaryl. In embodiments, each R10is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C6to C14aryl, and -C2to C9heteroaryl. In embodiments, each R10is independently selected from: -C1 to C20 alkyl, C3 to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C6to C14aryl, and -C2to C9heteroaryl. In embodiments, each R10is independently selected from: -C1to C20alkyl and -C2to C20alkenyl. In embodiments, each R10is independently selected from -C1to C20alkyl. In embodiments, each R10is independently selected from -C1 to C8 alkyl. In embodiments, each R11is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I. In embodiments, each R11is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -F, -Cl, -Br, and -I. In embodiments, each R11is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -OH, -NH2, -OC1to C20alkyl, -F, -Cl, -Br, and -I. In embodiments, each R11is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -OC1to C20alkyl, -F, -Cl, -Br, and -I. In embodiments, each R11is independently selected from: -C1to C20alkyl, -C3to C20cycloalkyl, -OC1to C20alkyl, -F, -Cl, -Br, and -I. In embodiments, each R11is independently selected from: -C1to C8alkyl, -C3to C8cycloalkyl, -OC1to C8alkyl, -F, -Cl, -Br, and -I. In embodiments, each R11is independently selected from -C1to C8alkyl. Formula (A) A radical of Formula (A) has the structure: wherein R1comprises a peptide radical. In embodiments, a radical of Formula (A) has the structure: wherein R1is a peptide radical. In embodiments, R1comprises a peptide radical containing less than or equal to 50 amino acids; less than or equal to 40 amino acids, less than or equal to 30 amino acids, less than or equal to 28 amino acids, less than or equal to 26 amino acids, less than or equal to 24 amino acids, less than or equal to 22 amino acids, less than or equal to 20 amino acids, less than or equal to 18 amino acids, less than or equal to 16 amino acids, less than or equal to 14 amino acids, less than or equal to 12 amino acids, less than or equal to 10 amino acids, less than or equal to 9 amino acids, less than or equal to 8 amino acids, less than or equal to 7 amino acids, less than or equal to 6 amino acids, less than or equal to 5 amino acids, less than or equal to 4 amino acids, less than or equal to 3 amino acids, less than or equal to 2 amino acids, or 1 amino acid. In embodiments, R1consists of a peptide radical containing less than or equal to 50 amino acids; less than or equal to 40 amino acids, less than or equal to 30 amino acids, less than or equal to 28 amino acids, less than or equal to 26 amino acids, less than or equal to 24 amino acids, less than or equal to 22 amino acids, less than or equal to 20 amino acids, less than or equal to 18 amino acids, less than or equal to 16 amino acids, less than or equal to 14 amino acids, less than or equal to 12 amino acids, less than or equal to 10 amino acids, less than or equal to 9 amino acids, less than or equal to 8 amino acids, less than or equal to 7 amino acids, less than or equal to 6 amino acids, less than or equal to 5 amino acids, less than or equal to 4 amino acids, less than or equal to 3 amino acids, less than or equal to 2 amino acids, or 1 amino acid. In embodiments, R1comprises a peptide radical containing greater than or equal to 2 amino acids. It will readily be appreciated that this embodiment may be combined with the above embodiment to form ranges e.g. greater than or equal to 2 and less than or equal to 50 etc. In embodiments, R1consists of a peptide radical containing greater than or equal to 2 amino acids. It will readily be appreciated that this embodiment may be combined with the above embodiment to form ranges e.g. greater than or equal to 2 and less than or equal to 50 etc. In embodiments, R1comprises a linear or branched peptide radical. In other embodiments, the R1comprises a cyclic peptide radical. In embodiments, the peptide radical is a linear or branched peptide radical. In other embodiments, the peptide radical is a cyclic peptide radical. In embodiments, R1comprises only natural amino acids. In embodiments, R1consists of only natural amino acids. In embodiments, R1comprises only unnatural amino acids. In embodiments, R1consists of only unnatural amino acids. In embodiments, R1comprises natural and unnatural amino acids. In embodiments, R1comprises at least one unnatural amino acid. In embodiments, R1comprises one or more amino acids selected from: Ala (A), Cys (C), Arg (R), Asp (D), Ser (S), Glu (E), Gln (Q), Lys (K), Gly (G), His (H), and Sar. In embodiments, the radical of Formula (A) comprises the structure selected from:

[0010] . In embodiments, the radical of Formula (A) has the structure selected from:

[0011] . In embodiments, the radical of Formula (A) comprises the structure selected from:

[0012] . In embodiments, the radical of Formula (A) has the structure selected from:

[0013] . In embodiments, the radical of Formula (A) comprises a structure that is an epimer of any of the structures defined herein. In embodiments, the radical of Formula (A) has a structure that is an epimer of any of the structures defined herein. In embodiments, the radical of Formula (A) comprises a structure that is a diastereomer of any of the structures defined herein. In embodiments, the radical of Formula (A) has a structure that is a diastereomer of any of the structures defined herein. In embodiments, the radical of Formula (A) comprises a structure that is an enantiomer of any of the structures defined herein. In embodiments, the radical of Formula (A) has a structure that is an enantiomer of any of the structures defined herein. In embodiments, the radical of Formula (A) comprises a structure that is a diastereomer of any of the structures defined herein, wherein two stereocentres have been inverted. In embodiments, the radical of Formula (A) has a structure that is a diastereomer of any of the structures defined herein, wherein two stereocentres have been inverted. In embodiments, the radical of Formula (A) comprises an N-terminus peptide nitrogen radical. In embodiments, the radical of Formula (A) is an N-terminus peptide nitrogen radical. In embodiments, the radical of Formula (A) comprises a C-terminus peptide carbon radical. In embodiments, the radical of Formula (A) is a C-terminus peptide carbon radical. In embodiments, each R1is a peptide radical defined by the structure: ; wherein each RXis a dipeptide or tripeptide radical; wherein each RYis a peptide diradical or is absent. In embodiments, each R1is defined by the structure: ; wherein each RXis a dipeptide or tripeptide radical; wherein each RYis a peptide diradical or is absent; and wherein each L3is a hydrocarbyl linker comprising 1 to 100 carbon atoms, for example 1 to 20 carbon atoms, such as 1 to 10 carbon atoms. In embodiments, each RXis a dipeptide radical. In embodiments, each RXis a tripeptide radical In embodiments, each RYis a peptide diradical. In embodiments, each RYis absent. In these embodiments, it will be apparent to a person of ordinary skill in the art that the radical of Formula (A) having the structure of , will be a radical of RX. It will be apparent that this will be the case for instances in which each R1is a peptide radical defined by the structure: . In embodiments in which each R1is a radical defined by the structure: , and each RYis absent, it will be apparent to a person of ordinary skill in the art that the radical of Formula (A) having the structure of , will be a radical of RX- L3-. In embodiments, RXcomprises only natural amino acids. In embodiments, RXconsists of only natural amino acids. In embodiments, RYcomprises only natural amino acids. In embodiments, RYconsists of only natural amino acids. In embodiments, RXcomprises only unnatural amino acids. In embodiments, RXconsists of only unnatural amino acids. In embodiments, RYcomprises only unnatural amino acids. In embodiments, RYconsists of only unnatural amino acids. In embodiments, RXcomprises natural and unnatural amino acids. In embodiments, RYcomprises natural and unnatural amino acids. In embodiments, RXcomprises at least one unnatural amino acid. In embodiments, RYcomprises at least one unnatural amino acid. In embodiments, each RXand each RYcomprise one or more amino acids selected from: Ala (A), Cys (C), Arg (R), Asp (D), Ser (S), Glu (E), Gln (Q), Lys (K), Gly (G), His (H), and Sar. In embodiments, RYcomprises or consists of a peptide diradical selected from: and wherein * denotes the point of attachment to the radical of RX. In embodiments, each RXradical is selected from: ,

[0014] . L3is a hydrocarbyl linker comprising 1 to 100 carbon atoms, for example 1 to 20 carbon atoms, such as 1 to 10 carbon atoms. In embodiments, L3comprises from 1 to 100 carbon atoms, from 1 to 90 carbon atoms, from 1 to 80 carbon atoms, from 1 to 70 carbon atoms, from 1 to 60 carbon atoms, from 1 to 50 carbon atoms, from 1 to 40 carbon atoms, from 1 to 30 carbon atoms, from 1 to 20 carbon atoms, from 1 to 10 carbon atoms, or from 1 to 8 carbon atoms. In embodiments, L3comprises a carbocyclyl group such as a cyclohexyl group. In embodiments, L3comprises a norbornyl group. In embodiments, L3comprises at one nitrogen atom, for example a terminal nitrogen radical. In embodiments, the terminal nitrogen radical is attached to a diradical of Formula (B). In embodiments, L3comprises a terminal nitrogen radical and a norbornyl group. In embodiments, L3is a diradical defined wherein denotes the point of attachment to the radical of RY(if RYis present) or RX(if RYis absent). In embodiments, L3is a diradical defined wherein denotes the point of attachment to the radical of RY(if RYis present) or RX(if RYis absent). In embodiments, each RXand each RYcomprise one or more amino acids selected from: Ala (A), Cys (C), Arg (R), Asp (D), Ser (S), Glu (E), Gln (Q), Lys (K), Gly (G), His (H), and Sar, for example wherein each RXand / or each RYcomprise one or more Cys (C); or wherein RYis absent. RXRYIn embodiments, each is selected from the amino acid sequences listed in Table 1, below: of different ways in which the above peptides could be attached to L3(i.e. when R1is a RXRYL3radical defined by the structure: ). It is particularly advantgeous when the point of attachment of RYto L3is via a Cys (C) sulfur atom. In embodiments, the peptide modified polymer is selected from:

[0015] ,

[0016] . In embodiments, the peptide modified polymer is selected from:

[0017] ; wherein p is an integer selected from 0 to 1000, q is an integer selected from 0 to 1000, and r is an integer selected from 0 to 1000. In embodiments, the peptide modified polymer is selected from: ,

[0018] šnd ; wherein p is an integer selected from 0 to 1000, q is an integer selected from 0 to 1000, and r is an integer selected from 0 to 1000. In embodiments, p is an integer selected from 0 to 1000, 0 to 800, 0 to 600, 0 to 400, 0 to 200, 0 to 190, 0 to 180, 0 to 170, 0 to 160, 0 to 150, 0 to 140, 0 to 130, 0 to 120, 0 to 110, 0 to 100, 0 to 95, 0 to 90, 0 to 85, 0 to 80, 0 to 75, 0 to 70, 0 to 65, 0 to 60, 0 to 55, 0 to 50, 0 to 45, 0 to 40, 0 to 35, 0 to 30, 0 to 25, 0 to 20, 0 to 15, 0 to 10, or 0 to 5. In embodiments, p is 1. In embodiments, q is an integer selected from 0 to 1000, 0 to 800, 0 to 600, 0 to 400, 0 to 200, 0 to 190, 0 to 180, 0 to 170, 0 to 160, 0 to 150, 0 to 140, 0 to 130, 0 to 120, 0 to 110, 0 to 100, 0 to 95, 0 to 90, 0 to 85, 0 to 80, 0 to 75, 0 to 70, 0 to 65, 0 to 60, 0 to 55, 0 to 50, 0 to 45, 0 to 40, 0 to 35, 0 to 30, 0 to 25, 0 to 20, 0 to 15, 0 to 10, or 0 to 5. In embodiments, q is 0. In embodiments, r is an integer selected from 0 to 1000, 0 to 800, 0 to 600, 0 to 400, 0 to 200, 0 to 190, 0 to 180, 0 to 170, 0 to 160, 0 to 150, 0 to 140, 0 to 130, 0 to 120, 0 to 110, 0 to 100, 0 to 95, 0 to 90, 0 to 85, 0 to 80, 0 to 75, 0 to 70, 0 to 65, 0 to 60, 0 to 55, 0 to 50, 0 to 45, 0 to 40, 0 to 35, 0 to 30, 0 to 25, 0 to 20, 0 to 15, 0 to 10, or 0 to 5. In embodiments, r is 0. In embodiments, p is 1, q is 0, and r is 0. Properties In embodiments, the peptide modified polymers are linear. In embodiments, the peptide modified polymers are branched or hyperbranched. DB influences properties such as intrinsic viscosity, solubility, and transfection efficacy. In embodiments, the peptide modified polymer has a degree of branching (DB) from 0.0-1.0. In embodiments, the peptide modified polymer has a degree of branching (DB) from 0.0-0.5. In embodiments, the peptide modified polymer has a degree of branching that is 0.0, about 0.1, about 0.2, about 0.3, about 0.4, about 0.5, about 0.6, or about 0.7. In embodiments, the peptide modified polymers are soluble in an aqueous solution. The aqueous solvent may comprise of 50-100% water by volume. In embodiments, the aqueous solvent comprises at least 90%, at least 92%, at least 94%, at least 96%, at least 98% or at least 99% water by volume. In embodiments, the pH of the aqueous solvent is in the range of about 5 to about 7.5 (e.g., about 5.2 to about 7.4). In embodiments, the aqueous solvent pH is a physiological pH. In embodiments, the temperature of the aqueous solution is in the range of about 25° C. to about 37° C. An aqueous solution may further comprise an organic solvent such as dimethylsulfoxide, dimethylformamide, acetic acid, or an alcohol (e.g., methanol, ethanol or isopropanol). In embodiments, the peptide modified polymers have a solubility in aqueous solution of at least about 30, at least about 10, at least about 5, at least about 2, or at least about 1 mg / mL. In embodiments, the peptide modified polymers have a solubility in an aqueous solution of at least about 1.6 mg / mL at about pH 7.4. In embodiments, the polymers of the invention are biodegradable or biocompatible. This represents a significant advantage when the peptide modified polymers are intended to be used in pharmaceutical applications. As used herein, “biodegradable” peptide modified polymers are those that, when introduced into cells, are broken down by the cellular machinery or by hydrolysis into components that the cells can either reuse or dispose of without significant toxic effect on the cells (i.e., fewer than about 20% of the cells are killed when the components are added to cells in vitro). In certain embodiments, the chemical reactions relied upon to break down the biodegradable polymers are uncatalysed. Biodegradability is a particular advantage of these peptide modified polymers delivery vectors, particularly for repeat administration where non-degradable vectors like PEI may accumulate or be difficult for the body to metabolise. The term “biocompatible,” as used herein is intended to describe compounds that are not toxic to cells. Polymers are “biocompatible” if their addition to cells in vitro results in less than or equal to 20% cell death, and their administration in vivo does not induce inflammation or other such adverse effects. In embodiments, the peptide modified polymer has a molecular weight (MW) of 1 kDa to 400 kDa, 2 kDa to 200 kDa, 3 kDa to 100 kDa, 4 kDa to 90 kDa, 5 kDa to 80 kDa, 6 kDa to 70 kDa, 7 kDa to 60 kDa, 8 kDa to 50 kDa, 1 kDa to 45 kDa, or 10 kDa to 40 kDa. In embodiments, the peptide modified polymer has a molecular weight (MW) of 1 kDa to 100 kDa, preferably 5 kDa to 50 kDa, more preferably 10 kDa to 40 kDa. The peptide modified polymers, nanoparticle compositions, and compositions thereof, provided by the present invention have low polydispersity (PI) parameters. A low PI means that the peptide modified polymers are highly uniform in size. Therefore, the low PI is advantageous when the peptide modified polymers are used in methods to prepare nanoparticle compositions, particularly those comprising a polynucleotide because each nanoparticle comprising said agent will have similar properties. As a consequence of this, there is a greater degree of control over the properties of the nanoparticle compositions of the present invention. This is particularly advantageous in pharmaceutical applications. In some embodiments, the polydispersity of the peptide modified polymer is less than 0.4, less than 0.35, preferably less than 0.3, more preferably less than 0.25, most preferably less than 0.2. Nanoparticle compositions The peptide modified polymers of the present invention may be used to prepare nanoparticle compositions and nanoparticle compositions comprising a polynucleotide. Accordingly, in embodiments, provided is a nanoparticle composition comprising the peptide modified polymer as defined herein, and a polynucleotide. In embodiments, the nanoparticle composition comprises one or more peptide modified polymers as defined herein, and a polynucleotide. In embodiments, the nanoparticle composition comprises one or more peptide modified polymers as defined herein, and one or more polynucleotides. The nanoparticle compositions of the present invention may comprise a broad range of different polynucleotides. It is also possible for the nanoparticle compositions to comprise one or more polynucleotides. The one or more polynucleotides may be adsorbed or encapsulated by the nanoparticles. Alternatively, one or more polynucleotides may be encapsulated by the nanoparticles, and one or more polynucleotides may also be adsorbed by the same nanoparticles. There may be mixtures of nanoparticles comprising one or more polynucleotides as described previously, with other nanoparticles comprising one or more polynucleotides, wherein the other nanoparticles comprising one or more polynucleotides comprise one or more polynucleotides that are different to the first. Alternatively, the other nanoparticles comprising one or more polynucleotides may comprise either the same or different polynucleotides, but the other nanoparticles comprising one or more polynucleotides have a different structure to the first nanoparticles comprising one or more polynucleotides. The nanoparticle compositions comprising one or more peptide modified polymers of the present invention are particularly useful when they comprise a polynucleotide because the peptide end caps of the peptide modified polymers enable binding to the peptide transporters PEPT1 (SLC15A1) and PEPT2 (SLC15A2), unlike traditional amine end caps. PEPT2 is a high-affinity transporter, and binding of the peptide modified polymers to this receptor enables receptor mediated cellular uptake of the polynucleotides in addition to increased polynucleotide endocytosis. Cellular uptake of the polynucleotide and polynucleotide endocytosis are increased due to the decreased proximity between the peptide modified polymer and the cell upon binding of the peptide end caps to PEPT2. The present invention allows the skilled person to fine tune and control the physical properties of the nanoparticles. For example, both the molecular weight and z-average mean diameter of the nanoparticles may be controlled. The molecular weight and z- average mean diameter of the nanoparticles are influenced by both the structure of the specific peptide based polymers used to prepare the nanoparticles, and the conditions used in the process. In many cases, the properties of the nanoparticles are dependent on their molecular weight and z-average mean diameter. In embodiments where the nanoparticle composition comprises a polynucleotide, the ability of the polynucleotide to be taken up by cells e.g. by endocytosis, will increase the efficacy of the therapeutic treatment. In addition, it is well known in the art that nanoparticles below a certain z-average mean diameter, for example 10 nm, are readily filtered from the blood by the kidneys and excreted. In embodiments where the nanoparticle composition comprises a polynucleotide, the therapeutic effect of the polynucleotide will not be experienced by a patient if the nanoparticles are readily excreted. Therefore, another advantage of the present invention is that nanoparticles may be designed to be larger than 10 nm to avoid this issue. In embodiments, the nanoparticle molecular weight (MW) of the nanoparticle composition is ≤5000 kDa. In embodiments, the nanoparticle molecular weight (MW) of the nanoparticle composition is ≤4000 kDa. In embodiments, the nanoparticle molecular weight (MW) of the nanoparticle composition is ≤3000 kDa. In embodiments, the nanoparticle molecular weight (MW) of the nanoparticle composition is ≤2000 kDa. In embodiments, the nanoparticle molecular weight (MW) of the nanoparticle composition is ≤1000 kDa. In embodiments, the nanoparticle molecular weight (MW) of the nanoparticle composition is ≤800 kDa. In embodiments, the nanoparticle molecular weight (MW) of the nanoparticle composition is ≤600 kDa. In embodiments, the nanoparticle molecular weight (MW) of the nanoparticle composition is ≤500 kDa. In embodiments, the nanoparticle molecular weight (MW) of the nanoparticle composition is ≥500 kDa and ≤4000 kDa. In embodiments, the z-average mean diameter of the nanoparticles is from 1 to 1000 nm, as measured by dynamic light scattering. In embodiments, the z-average mean diameter of the nanoparticles is from 5 to 900 nm, as measured by dynamic light scattering. In embodiments, the z-average mean diameter of the nanoparticles is from 10 to 700 nm, as measured by dynamic light scattering. In embodiments, the z-average mean diameter of the nanoparticles is from 20 to 600 nm, as measured by dynamic light scattering. In embodiments, the z-average mean diameter of the nanoparticles is from 30 to 500 nm, as measured by dynamic light scattering. In embodiments, the z-average mean diameter of the nanoparticles is from 40 to 400 nm, as measured by dynamic light scattering. In embodiments, the z-average mean diameter of the nanoparticles is from 50 to 300 nm, as measured by dynamic light scattering. In embodiments, the z-average mean diameter of the nanoparticles is from 100 to 250 nm, as measured by dynamic light scattering. In embodiments, the z-average mean diameter of the nanoparticles is from 10 to 500 nm, preferably from 100 to 250 nm, as measured by dynamic light scattering. In embodiments, the nanoparticles comprise a peptide modified polymer wherein the peptide modified polymer is DD90-GlySar and the z-average mean diameter of the nanoparticles is from 10 to 1000 nm, as measured by dynamic light scattering. In embodiments, the z-average mean diameter of the nanoparticles is from 20 to 500 nm, as measured by dynamic light scattering. In embodiments, the z-average mean diameter of the nanoparticles is from 50 to 400 nm, as measured by dynamic light scattering. In embodiments, the z-average mean diameter of the nanoparticles is from 100 to 300 nm, as measured by dynamic light scattering. In embodiments, the z-average mean diameter of the nanoparticles is from 120 to 280 nm, as measured by dynamic light scattering. In embodiments, the z-average mean diameter of the nanoparticles is from 140 to 260 nm, as measured by dynamic light scattering. In embodiments, the z-average mean diameter of the nanoparticles is from 160 to 240 nm, as measured by dynamic light scattering. In embodiments, the z-average mean diameter of the nanoparticles is from 180 to 220 nm, as measured by dynamic light scattering. In embodiments, the z-average mean diameter of the nanoparticles is from 190 to 210 nm, as measured by dynamic light scattering. In embodiments, the z-average mean diameter of the nanoparticles is from 195 to 205 nm, as measured by dynamic light scattering, e.g.201 nm. In embodiments, the ratio of peptide modified polymer to polynucleotide in the nanoparticle composition is about 50 to about 1, and the z-average mean diameter of the nanoparticles is from 195 to 205 nm, as measured by dynamic light scattering, e.g.201 nm. In embodiments, the nanoparticles comprise a peptide modified polymer wherein the peptide modified polymer is DD90-AlaLys and the z-average mean diameter of the nanoparticles is from 10 to 1000 nm, as measured by dynamic light scattering. In embodiments, the z-average mean diameter of the nanoparticles is from 20 to 900 nm, as measured by dynamic light scattering. In embodiments, the z-average mean diameter of the nanoparticles is from 30 to 800 nm, as measured by dynamic light scattering. In embodiments, the z-average mean diameter of the nanoparticles is from 40 to 700 nm, as measured by dynamic light scattering. In embodiments, the z-average mean diameter of the nanoparticles is from 50 to 600 nm, as measured by dynamic light scattering. In embodiments, the z-average mean diameter of the nanoparticles is from 60 to 500 nm, as measured by dynamic light scattering. In embodiments, the z-average mean diameter of the nanoparticles is from 70 to 400 nm, as measured by dynamic light scattering. In embodiments, the z-average mean diameter of the nanoparticles is from 80 to 300 nm, as measured by dynamic light scattering. In embodiments, the z-average mean diameter of the nanoparticles is from 90 to 200 nm, as measured by dynamic light scattering. In embodiments, the z-average mean diameter of the nanoparticles is from 100 to 150 nm, as measured by dynamic light scattering. In embodiments, the z-average mean diameter of the nanoparticles is from 110 to 140 nm, as measured by dynamic light scattering. In embodiments, the z-average mean diameter of the nanoparticles is from 120 to 130 nm, as measured by dynamic light scattering, e.g.125 nm. In embodiments, the ratio of peptide modified polymer to polynucleotide in the nanoparticle composition is about 50 to about 1, and the z-average mean diameter of the nanoparticles is from 120 to 130 nm, as measured by dynamic light scattering, e.g.125 nm. The nanoparticle compositions of the present invention are particularly useful because they have a spherical shape. The spherical shape of the nanoparticles of the present invention is a significant advantage because this allows for maximum interaction at the cell surface, so increases cellular uptake of polynucleotides by endocytosis. Spherical nanoparticles have many different applications due to their high surface area to volume ratio. The spherical shape of the nanoparticles of the present invention is also a significant advantage because in embodiments where the nanoparticle compositions comprise a polynucleotide, the spherical shape means that a greater proportion of the polynucleotide is encapsulated by the nanoparticles. Therefore, the encapsulation efficiency of the compositions is high. A high encapsulation efficiency is beneficial because this results in a stronger therapeutic effect with reduced side effects. In embodiments, the encapsulation efficiency of the nanoparticle composition comprising a polynucleotide is at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 98%, or at least 99%. In embodiments, the encapsulation efficiency is at least 99%. In embodiments, the encapsulation efficiency of the nanoparticle composition comprising a polynucleotide is at least about 95%, e.g. about 98%, and the nanoparticle composition comprises the peptide modified polymer DD90-AlaLys. In embodiments, the encapsulation efficiency of the nanoparticle composition comprising a polynucleotide is at least about 95%, e.g. about 99%, and the nanoparticle composition comprises the peptide modified polymer is DD90-GlySar. The encapsulation efficiency of DD90 is about 67%, and the encapsulation efficiency of DD90-118 is about 99%. The spherical shape of the nanoparticles of the present invention is also advantageous because this results in homogenous intramolecular interactions, for example hydrogen bonding, electrostatic interactions, and Van der Waals’ forces, between a polynucleotide that is encapsulated by or adsorbed onto the surface of the nanoparticle compositions, and the nanoparticle compositions themselves. In preferred embodiments the nanoparticle composition comprises nanospheres. In preferred embodiments the nanoparticle composition comprises nanospheres. Following the methods of the present invention that are described herein, nanospheres are formed spontaneously. The spontaneous formation of nanospheres is particularly important when the nanoparticle compositions of the present invention comprise a polynucleotide because the spontaneous formation of nanospheres results in a high encapsulation efficiency – the nanospheres spontaneously encapsulate the polynucleotide in the methods of the present invention. These reliable methods to produce nanospheres and nanospheres comprising a polynucleotide are a significant advantage of the present invention. The nanoparticle compositions provided by the present invention have low polydispersity (PI) parameters. A low PI means that the nanoparticles are highly uniform in size. Therefore, the low PI is advantageous when the nanoparticle compositions of the present invention comprise a polynucleotide because each nanoparticle comprising said agent will have similar properties. As a consequence of this, there is a greater degree of control over the properties of the nanoparticle compositions of the present invention. This is particularly advantageous in pharmaceutical applications. In some embodiments, the polydispersity of the nanoparticle composition is less than 0.4, less than 0.35, preferably less than 0.3, more preferably less than 0.25, most preferably less than 0.2. The nanoparticle compositions provided by the present invention may conveniently have positive ζ-potentials. Positive ζ-potentials are an advantageous property of the nanoparticle compositions of the present invention because in general, polynucleotides (which are often negatively charged) are more likely to adsorb onto the surface of the nanoparticle or be encapsulated by the nanoparticles. As one of ordinary skill in the art will appreciate, it is not desirable for nanoparticle compositions to have too positive a ζ- potential because this can result in undesired aggregation and solidification. Additionally, nanoparticle compositions that have too positive a ζ-potential can be toxic to cells and / or be cleared quicker in vivo due to surface adsorption of serum proteins. Advantageously, in embodiments, the nanoparticle compositions of the present invention have positive ζ- potentials that are low enough to avoid undesired aggregation and solidification. The positive charge of the peptide modified polymer backbone enables complexation with polynucleotides, but does not result in undesired aggregation and solidification. The nanoparticle compositions of the present invention may be formulated to further optimise the stability of these compositions. In embodiments, the ζ-potential of the nanoparticle composition is from about 0 mV to about +60 mV, about +1 mV to about +50 mV, about +10 mV to about +45 mV, about +20 mV to about +40 mV, about +22 mV to about +38 mV, about +22 mV to about +34 mV, about +24 mV to about +32 mV, or about +26 mV to about +30 mV. In embodiments, the ζ-potential of the nanoparticle composition is from about +26 mV to about +30 mV. In embodiments, the nanoparticle composition comprises a peptide modified polymer wherein the peptide modified polymer is DD90-GlySar and the ζ-potential of the nanoparticle composition is about +27 mV. In embodiments, the nanoparticle composition comprises a peptide modified polymer wherein the peptide modified polymer is DD90-AlaLys and the ζ-potential of the nanoparticle composition is about +28 mV. In embodiments, the nanoparticle composition comprises a polynucleotide, wherein the polynucleotide is stable in aqueous solution at temperatures up to 60 °C, preferably up to 70 °C, more preferably up to 80 °C. It may be the case that being adsorbed onto the surface of, or encapsulated by the nanoparticle provides an additional stabilising effect to the polynucleotide and this makes it more resistant to degradation. “Stable” in this context may be used to refer to the proportion of the polynucleotide that has degraded. As one of ordinary skill in the art will be aware, a number of analytical techniques may be used to determine the purity of a sample. These analytical techniques include, but are not limited to: NMR, for example1H NMR and19F NMR; HPLC; SFC; GC; LC-MS; colourimetry; titration; and IR. For example, in embodiments, the amount of polynucleotide that has degraded in aqueous solution at a given temperature is <30%. In embodiments, the amount of polynucleotide that has degraded in aqueous solution at a given temperature is <20%. In embodiments, the amount of polynucleotide that has degraded in aqueous solution at a given temperature is <10%. In embodiments, the amount of polynucleotide that has degraded in aqueous solution at a given temperature is <5%. In embodiments, the amount of polynucleotide that has degraded in aqueous solution at a given temperature is <1%. Pharmaceutical compositions As will be understood by the skilled person, the peptide modified polymers and nanoparticle compositions defined herein may be formulated into pharmaceutical compositions. In embodiments, the pharmaceutical compositions comprise a polynucleotide. Accordingly, in an aspect are compositions comprising a peptide modified polymer as defined herein in addition to a polynucleotide, or a nanoparticle composition as defined herein; and a pharmaceutically acceptable excipient. In embodiments, the polynucleotide is DNA. In embodiments, the polynucleotide is RNA. In embodiments, the RNA is mRNA, ssRNA, circRNA, dsRNA, saRNA, siRNA, shRNA, or miRNA. In embodiments, the RNA is mRNA. In embodiments, the polynucleotide is selected from an antisense oligonucleotide (ASO) and a CRISPR oligonucleotide. The compositions may be used according to the methods disclosed herein. The pharmaceutically acceptable excipient can be any such excipient known in the art including those described in, for example, Remington's Pharmaceutical Sciences, Mack Publishing Co. (A. R. Gennaro edit. 1985). Pharmaceutical compositions of the nanoparticle compositions comprising a polynucleotide presently disclosed may be prepared by conventional means known in the art including, for example, mixing at least one presently disclosed nanoparticle composition comprising a peptide modified polymer in addition to a polynucleotide, or a nanoparticle composition as defined herein; with a pharmaceutically acceptable excipient. Thus, in embodiments, the present invention provides a pharmaceutical dosage form comprising a peptide modified polymer in addition to a polynucleotide, or a nanoparticle composition as defined herein, and a pharmaceutically acceptable excipient, wherein the dosage form is formulated to provide, when administered (e.g. when administered orally), an amount of said peptide modified polymer in addition to a polynucleotide, or a nanoparticle composition as defined herein, comprising a polynucleotide sufficient to treat a disease or disorder as described herein. A pharmaceutical composition or dosage form of the invention can include an agent e.g. a polynucleotide, and another carrier, e.g. compound or composition, inert or active, such as a detectable agent, label, adjuvant, diluent, binder, stabilizer, buffers, salts, lipophilic solvents, preservative, adjuvant or the like. Carriers also include pharmaceutical excipients and additives, for example, proteins, peptides, amino acids, lipids, and carbohydrates (e.g. sugars, including monosaccharides, di-, tri-, tetra-, and oligosaccharides; derivatized sugars such as alditols, aldonic acids, esterified sugars and the like; and polysaccharides or sugar polymers), which can be present singly or in combination, comprising alone or in combination 1 to 99.99% by weight or volume. Exemplary protein excipients include serum albumin such as human serum albumin (HSA), recombinant human albumin (rHA), gelatin, casein, and the like. Representative amino acid / antibody components, which can also function in a buffering capacity, include alanine, glycine, arginine, betaine, histidine, glutamic acid, aspartic acid, cysteine, lysine, leucine, isoleucine, valine, methionine, phenylalanine, aspartame, and the like. Carbohydrate excipients are also intended within the scope of this invention, examples of which include but are not limited to monosaccharides such as fructose, maltose, galactose, glucose, D-mannose, sorbose, and the like; disaccharides, such as lactose, sucrose, trehalose, cellobiose, and the like; polysaccharides, such as raffinose, melezitose, maltodextrins, dextrans, starches, and the like; and alditols, such as mannitol, xylitol, maltitol, lactitol, xylitol sorbitol (glucitol) and myoinositol. Carriers which may be used include a buffer or a pH adjusting agent; typically, the buffer is a salt prepared from an organic acid or base. Representative buffers include organic acid salts such as salts of citric acid, ascorbic acid, gluconic acid, carbonic acid, tartaric acid, succinic acid, acetic acid, or phthalic acid; Tris, tromethamine hydrochloride, or phosphate buffers. Additional carriers include polymeric excipients / additives such as polyvinylpyrrolidones, ficolls (a polymeric sugar), dextrates (e.g. cyclodextrins, such as 2- hydroxypropyl-β-cyclodextrin), polyethylene glycols, flavoring agents, antimicrobial agents, sweeteners, antioxidants, antistatic agents, surfactants (e.g. polysorbates such as “TWEEN 20” and “TWEEN 80”), lipids (e.g. phospholipids, fatty acids), steroids (e.g. cholesterol), and chelating agents (e.g. EDTA). In embodiments, the excipient is a hydrophilic polymer. In embodiments, the hydrophilic polymer is “A24-121”, which is a polymer formed from di(ethylene glycol) diacrylate (“A”), (±)-3-amino-1,2-propanediol (“24”), and 2,2′- (ethylenedioxy)bis(ethylamine) (“121”) . The structure of this polymer is shown below: In embodiments, the excipient is A24-121 and the composition comprises about 0.1%, about 1%, about 2%, about 3%, about 4%, about 5%, about 6%, about 7%, about 8%, about 9%, about 10%, about 15%, about 20%, about 30%, about 40%, or about 50% of said excipient. In embodiments, the excipient is A24-121 and the composition comprises about 2%, about 7%, or about 10% of said excipient. Advantageously, A24-121 may provide a biodegradable alternative to non- degradable PEGs that are commonly included in non-viral vector formulation. PEG is conjugated to a lipid to enable hydrophobic inclusion into the LNP. “A24-121” is a cationic, hydrophilic polymer that would complex by electrostatic interactions with nucleic acids. In embodiments, the excipient is DMSO and the composition comprises about 0.1%, about 0.5%, about 1%, about 2%, about 3%, about 4%, about 5%, about 6%, about 7%, about 8%, about 9%, or about 10% of said excipient. In embodiments, the excipient is DMSO and the composition comprises about 0.5%, about 1%, about 2%, about 3%, about 4%, or about 5% of said excipient. In embodiments, the excipient is DMSO and the composition comprises about 0.5% to about 5% of said excipient. In embodiments, the excipient is selected from: PEG, lipids (e.g. cholesterol), solute and osmolarity regulators such as sugars (glucose) and buffers (saline). The present invention also provides pharmaceutical compositions, and kits comprising said compositions, which contain at least one nanoparticle composition comprising a polynucleotide and at least one further pharmaceutically-active agent. These pharmaceutical compositions and kits may be adapted to allow simultaneous, subsequent and / or separate administration of the nanoparticle composition comprising a polynucleotide and the further active agent. For example, the nanoparticle composition comprising a polynucleotide and the further active agent may be formulated in separate dosage forms, e.g. in separate tablets, capsules, lyophilizates, suspensions or liquids, or they may be formulated in the same dosage form, e.g. in the same tablet, capsule, lyophilizate, suspension or liquid. Where the nanoparticle composition comprising a polynucleotide and the further active agent are formulated in the same dosage form, the nanoparticle composition comprising a polynucleotide and the further active agent may be present substantially in admixture, e.g. within the core of a tablet or capsule, or they may be present substantially in discrete regions of the dosage form, e.g. in separate layers or areas of the same tablet or capsule. In one embodiment, the pharmaceutical dosage form comprises a further agent which is capable of treating a disease or condition as described herein. In further embodiments, the present invention provides a pharmaceutical composition comprising: (i) a nanoparticle composition comprising a polynucleotide as described herein; (ii) a further active agent; and (iii) a pharmaceutically acceptable excipient. In embodiments, the further active agent is an agent which is capable of treating or preventing a disease or condition, as described herein, for example, when administered orally to a subject. In embodiments, the further active agent is an agent which is capable of treating or preventing a disease or condition, as described herein, for example, when administered intravenously to a subject. The presently disclosed nanoparticle compositions comprising a polynucleotide and pharmaceutical compositions can be used in an animal or human. Thus, a presently disclosed compound can be formulated as a pharmaceutical composition for oral, buccal, parenteral (e.g. intravenous, intramuscular or subcutaneous), topical, rectal or intranasal administration or in a form suitable for administration by inhalation or insufflation. In particular embodiments, the nanoparticle composition comprising a polynucleotide or pharmaceutical composition is formulated for systemic administration, e.g. via a non- parenteral route. In one embodiment, the nanoparticle composition comprising a polynucleotide or pharmaceutical composition is formulated for oral administration, e.g. in solid, liquid or suspension form. Such modes of administration and the methods for preparing appropriate pharmaceutical compositions are described, for example, in Gibaldi’s Drug Delivery Systems in Pharmaceutical Care (1st ed., American Society of Health-System Pharmacists 2007). In embodiments, the composition is packaged in a non-viral delivery system. In embodiments, the non-viral delivery system is selected from: (i) a nanoparticle, for example a lipid nanoparticle, a polypeptide nanoparticle, a silica nanoparticle, a gold nanoparticle, a polymeric nanoparticle; (ii) a microparticle; or (iii) a micelle, a lipoplex, a liposome, a dendrimer, a cationic nano emulsion, an inorganic carrier (such as CaP), a polymer and a lipid hybrid carrier. The pharmaceutical compositions can be formulated so as to provide an extended release of the active ingredient therein using, for example, hydroxypropyl methyl cellulose in varying proportions to provide the desired release profile, other polymer matrices, liposomes and / or microspheres. The pharmaceutical compositions can also optionally contain opacifying agents and may be of a composition that releases the active ingredient(s) only, or preferentially, in a certain portion of the gastrointestinal tract, optionally, in a delayed manner, e.g. by using an enteric coating. Examples of embedding compositions include polymeric substances and waxes. The nanoparticle composition comprising a polynucleotide can also be in micro-encapsulated form, if appropriate, with one or more pharmaceutically acceptable carriers, excipients, or diluents well known in the art (see, e.g., Remington’s). The nanoparticle compositions comprising a polynucleotide presently disclosed may be formulated for sustained delivery according to methods well known to those of ordinary skill in the art. Examples of such formulations can be found in United States Patents 3,119,742; 3,492,397; 3,538,214; 4,060,598; and 4,173,626. In solid dosage forms for oral administration (e.g. capsules, tablets, pills, dragees, powders, granules and the like), the nanoparticle composition comprising a polynucleotide is mixed with one or more pharmaceutically acceptable carriers, excipients, or diluents, such as sodium citrate or dicalcium phosphate, and / or any of the following: (1) fillers or extenders, such as starches, lactose, sucrose, glucose, mannitol, microcrystalline cellulose, calcium phosphate and / or silicic acid; (2) binders, such as, for example, carboxymethylcellulose, alginates, gelatin, pregelatinized maize starch, polyvinyl pyrrolidone, hydroxypropyl methylcellulose, sucrose and / or acacia; (3) humectants, such as glycerol; (4) disintegrating agents, such as agar-agar, calcium carbonate, sodium starch glycolate, potato or tapioca starch, alginic acid, certain silicates, and sodium carbonate; (5) solution retarding agents, such as paraffin; (6) absorption accelerators, such as quaternary ammonium compounds; (7) wetting agents, such as, for example, sodium lauryl sulphate, acetyl alcohol and glycerol monostearate; (8) absorbents, such as kaolin and bentonite clay; (9) lubricants, such as talc, silica, calcium stearate, magnesium stearate, solid polyethylene glycols, sodium lauryl sulfate, and mixtures thereof; and (10) coloring agents. In the case of capsules, tablets, and pills, the pharmaceutical compositions can also comprise buffering agents. Solid compositions of a similar type can also be prepared using fillers in soft and hard-filled gelatin capsules, and excipients such as lactose or milk sugars, as well as high molecular weight polyethylene glycols and the like. A tablet can be made by compression or molding, optionally with one or more accessory ingredients. Compressed tablets can be prepared using binders (for example, gelatin or hydroxypropyl methyl cellulose), lubricants, inert diluents, preservatives, disintegrants (for example, sodium starch glycolate or cross-linked sodium carboxymethyl cellulose), surface-actives, and / or dispersing agents. Molded tablets can be made by molding in a suitable machine a mixture of the powdered nanoparticle composition comprising an active agent moistened with an inert liquid diluent. The tablets and other solid dosage forms, such as dragees, capsules, pills, and granules, can optionally be scored or prepared with coatings and shells, such as enteric coatings and other coatings well known in the art. In embodiments, the pharmaceutical compositions are administered orally in a liquid form. Liquid dosage forms for oral administration of a nanoparticle composition comprising an active agent include pharmaceutically acceptable emulsions, microemulsions, solutions, suspensions, syrups, and elixirs. Liquid preparations for oral administration may be presented as a dry product for constitution with water or other suitable vehicle before use. In addition to the nanoparticle composition comprising a polynucleotide, the liquid dosage forms can contain inert diluents commonly used in the art, such as, for example, water or other solvents, solubilizing agents and emulsifiers, such as ethyl alcohol, isopropyl alcohol, ethyl carbonate, ethyl acetate, benzyl alcohol, benzyl benzoate, propylene glycol, 1,3-butylene glycol, oils (e.g. cottonseed, groundnut, corn, germ, olive, castor and sesame oils), glycerol, tetrahydrofuryl alcohol, polyethylene glycols and fatty acid esters of sorbitan, and mixtures thereof. In addition to inert diluents, the liquid pharmaceutical compositions can include adjuvants such as wetting agents, emulsifying and suspending agents, sweetening, flavoring, coloring, perfuming and preservative agents, and the like. Suspensions, in addition to the nanoparticle composition comprising a polynucleotide can contain suspending agents such as, but not limited to, ethoxylated isostearyl alcohols, polyoxyethylene sorbitol and sorbitan esters, microcrystalline cellulose, aluminum metahydroxide, bentonite, agar-agar and tragacanth, and mixtures thereof. Suitable liquid preparations may be prepared by conventional means with a pharmaceutically acceptable additive(s) such as a suspending agent (e.g. sorbitol syrup, methyl cellulose or hydrogenated edible fats); emulsifying agent (e.g. lecithin or acacia); non-aqueous vehicle (e.g. almond oil, oily esters or ethyl alcohol); and / or preservative (e.g. methyl or propyl p-hydroxybenzoates or sorbic acid). The nanoparticle compositions comprising a polynucleotide can also be administered as a bolus, electuary, or paste. For buccal administration, the composition may take the form of tablets or lozenges formulated in a conventional manner. In some embodiments the pharmaceutical compositions are administered by non- oral means such as by topical application, transdermal application, injection, eye drops, aerosol, and the like. In related embodiments, the pharmaceutical compositions are administered parenterally by injection, infusion, or implantation (e.g. intravenous, intramuscular, intra-arterial, subcutaneous, and the like). Presently disclosed nanoparticle compositions comprising a polynucleotide may be formulated for parenteral administration by injection, including using conventional catheterization techniques or infusion. Formulations for injection may be presented in unit dosage form, e.g. in ampules or in multi-dose containers, with an added preservative. The compositions may take such forms as suspensions, solutions or emulsions in oily or aqueous vehicles, and may contain a formulating agent such as a suspending, stabilizing and / or dispersing agent recognized by those of skill in the art. Alternatively, the nanoparticle composition comprising a polynucleotide may be in powder form for reconstitution with a suitable vehicle, e.g. sterile pyrogen-free water, before use. The pharmaceutical compositions may be administered directly to the central nervous system. Accordingly, in certain embodiments the compositions are administered directly to the central nervous system so as to avoid the blood brain barrier. In some embodiments, the composition can be administered via direct spinal cord injection. In embodiments, the composition is administered by intrathecal injection. In some embodiments, the composition is administered via intracerebroventricular injection. In embodiments, the composition is administered into a cerebral lateral ventricle. In embodiments, the composition is administered into both cerebral lateral ventricles. In additional embodiments, the composition is administered via intrahippocampal injection. The compositions may be administered in one injection or in multiple injections. In other embodiments, the composition is administered to more than one location (e.g. to two sites in the central nervous system). The pharmaceutical compositions can be in the form of sterile injections. The pharmaceutical compositions can be sterilized by, for example, filtration through a bacteria-retaining filter, or by incorporating sterilizing agents in the form of sterile solid compositions which can be dissolved in sterile water, or some other sterile injectable medium immediately before use. To prepare such a composition, the nanoparticle composition comprising a polynucleotide is dissolved or suspended in a parenterally acceptable liquid vehicle. Exemplary vehicles and solvents include, but are not limited to, water, water adjusted to a suitable pH by addition of an appropriate amount of hydrochloric acid, sodium hydroxide or a suitable buffer, 1,3-butanediol, Ringer’s solution and isotonic sodium chloride solution. The pharmaceutical composition can also contain one or more preservatives, for example, methyl, ethyl or n-propyl p-hydroxybenzoate. To improve solubility, a dissolution enhancing or solubilizing agent can be added or the solvent can contain 10-60% w / w of propylene glycol or the like. The pharmaceutical compositions can contain one or more pharmaceutically acceptable sterile isotonic aqueous or nonaqueous solutions, dispersions, suspensions or emulsions, or sterile powders, which can be reconstituted into sterile injectable solutions or dispersions just prior to use. Such pharmaceutical compositions can contain antioxidants; buffers; bacteriostats; solutes, which render the formulation isotonic with the blood of the intended recipient; suspending agents; thickening agents; preservatives; and the like. Examples of suitable aqueous and nonaqueous carriers, which can be employed in the pharmaceutical compositions of the invention include water, ethanol, polyols (such as glycerol, propylene glycol, polyethylene glycol, and the like), and suitable mixtures thereof, vegetable oils, such as olive oil, and injectable organic esters, such as ethyl oleate. Proper fluidity can be maintained, for example, by the use of coating materials, such as lecithin, by the maintenance of the required particle size in the case of dispersions, and by the use of surfactants. Controlled release parenteral compositions can be in form of aqueous suspensions, nanoparticle composition comprising a polynucleotide in microspheres, nanoparticle composition comprising a polynucleotide in microcapsules, nanoparticle composition comprising a polynucleotide in magnetic microspheres, oil solutions, oil suspensions, emulsions, or the nanoparticle composition comprising a polynucleotide can be incorporated in biocompatible carrier(s), nanoparticles, implants or infusion devices. Materials for use in the preparation of microspheres and / or microcapsules include, but are not limited to, biodegradable / bioerodible polymers such as polyglactin, poly-(isobutyl cyanoacrylate), poly(2-hydroxyethyl-L-glutamine) and poly(lactic acid). Biocompatible carriers which can be used when formulating a controlled release parenteral formulation include carbohydrates such as dextrans, proteins such as albumin, lipoproteins or antibodies. Materials for use in implants can be non-biodegradable, e.g. polydimethylsiloxane, or biodegradable such as, e.g., poly(caprolactone), poly(lactic acid), poly(glycolic acid) or poly(ortho esters). For topical administration, a presently disclosed nanoparticle composition comprising an active agent may be formulated as an ointment or cream. Presently disclosed nanoparticle compositions comprising a polynucleotide may also be formulated in rectal compositions such as suppositories or retention enemas, e.g. containing conventional suppository bases such as cocoa butter or other glycerides. For intranasal administration or administration by inhalation, presently disclosed nanoparticle compositions comprising a polynucleotide may be conveniently delivered in the form of a solution or suspension from a pump spray container that is squeezed or pumped by the patient or as an aerosol spray presentation from a pressurized container or a nebulizer, with the use of a suitable propellant, e.g. dichlorodifluoromethane, trichlorofluoromethane, dichlorotetrafluoroethane, carbon dioxide or other suitable gas. In the case of a pressurized aerosol, the dosage unit may be determined by providing a valve to deliver a metered amount. The pressurized container or nebulizer may contain a solution or suspension of the presently disclosed nanoparticle composition comprising an active agent. Capsules and cartridges (made, for example, from gelatin) for use in an inhaler or insufflator may be formulated containing a powder mix of a presently disclosed nanoparticle composition comprising a polynucleotide and a suitable powder base such as lactose or starch. In embodiments, the composition is formulated for nebulisation, aerosol delivery, or intranasal delivery. In an aspect the present invention provides a nasal spray comprising the composition defined herein. Generally, the nanoparticle composition comprising a polynucleotide and pharmaceutical compositions thereof described herein are administered in an effective amount or quantity sufficient to treat or prevent a disease or condition in a subject in need thereof. Typically, the dose can be adjusted within this range based on, e.g., age, physical condition, body weight, sex, diet, time of administration, and other clinical factors. Determination of an effective amount is well within the capability of those skilled in the art. Medical uses In another aspect the present invention provides an in vitro method of delivering polynucleotides to cells, the method comprising contacting the composition as defined herein, or the nasal spray as defined herein, with said cells. Advantageously, the nanoparticle compositions provided by the present invention are suitable for use as transfection agents to deliver polynucleotides to cells. The peptide modified polymers comprised by the nanoparticle compositions provided by the present invention comprise amine groups that may conveniently be positively charged under physiological conditions. The positive charge is particularly advantageous because it means that the compositions are suitable for use as transfection agents to deliver (negatively charged) polynucleotides to cells. Advantageously, the peptide end caps of the peptide modified polymers of the present invention enable binding to the peptide transporters PEPT1 (SLC15A1) and PEPT2 (SLC15A2). PEPT2 is a high-affinity transporter that is predominantly expressed in various cells including those of the kidney, lung, nasal epithelium, spleen and eye. This makes them suitable for use as transfection agents. As stated above, the nanoparticle compositions provided by the present invention are particularly useful because they may further comprise a polynucleotide. The polynucleotide may be incorporated within the structure of the peptide modified polymer or nanoparticle composition, for example it may be encapsulated, or adsorbed onto its surface. As a consequence of this, the nanoparticle compositions comprising a polynucleotide, and nasal sprays comprising the same, are particularly useful in in vitro methods of delivering polynucleotides to cells. In another aspect the present invention provides a composition as defined herein, or a nasal spray as defined herein, for use in treating a disease or disorder. The peptide modified polymers and nanoparticle compositions, and nasal sprays comprising said peptide modified polymers and nanoparticle compositions provided by the present invention are particularly useful as transfection agents. The polynucleotide may be pharmaceutically active, so the peptide modified polymers and nanoparticle compositions comprising a polynucleotide, and nasal sprays comprising the same, are particularly useful in therapy. The peptide modified polymers and nanoparticle compositions comprising the same may be formulated as sprays, e.g. nasal sprays. Nasal sprays are particularly useful for treating patients suffering from diseases or disorders associated with the lungs. Accordingly, in embodiments, provided is a composition or nasal spray for use as defined herein, wherein the disease or disorder is a lung disease or disorder. As a person skilled in the art will appreciate, there are many medical indications for which it is necessary to transfect cells using polynucleotides. The epithelial layer functions as a protective barrier against external agents and surrounds major organs such as the lung, eye and skin. However, despite remaining a highly desirable route for advanced therapeutics such as nucleic acid therapies, the epithelial layer is difficult to transfect using conventional transfection agents. Advantageously, the peptide modified polymers and nanoparticle compositions of the present invention are effective in transfecting cells using polynucleotides. Accordingly, the peptide modified polymers and nanoparticle compositions of the present invention are particularly useful in treating lung diseases or disorders. In embodiments, the disease or disorder is selected from: abnormal diffusion, abnormal perfusion, abnormal ventilation, accelerated silicosis, actinomycosis, acute air space pneumonia (acute bacterial pneumonia), acute bronchiolitis, acute congestion, acute infections of the lung, acute interstitial pneumonia, acute necrotizing viral pneumonia, acute organic dust toxic syndrome, acute pneumonia, acute radiation pneumonitis, acute rheumatic fever, acute silicosis, adenocarcinoma, adenoid cystic carcinoma, adenosquamous carcinoma, adenovirus, adult respiratory distress syndrome (shock lung), agenesis, AIDS, air embolism, allergic bronchopulmonary mycosis, allergic granulomatosis and angiitis (Churg-Strauss), allograft rejection, aluminium pneumoconiosis, alveolar microlithiasis, alveolar proteinosis, amoebic lung abscess, amniotic fluid embolism, amyloidosis of the lung, acute tracheobronchitis, anomalies of pulmonary vasculature, anomalous pulmonary venous return, apiration pneumonia, aplasia, asbestosis, asbestos-related diseases, aspergillosis, asthma, atelectasis, atriovenous fistulas, atypical mycobacterial infection, bacteremia, bacterial pneumonia, benign clear cell tumor, benign epithelial tumors, benign fibrous mesothelioma, berylliosis, blastomycosis, bromchial atresia, bronchial asthma, bronchial carcinoid tumor, bronchial isomerism, bronchial obstruction, bronchial stenosis, bronchiectasis, bronchiolalveolar carcinoma, bronchiolitis, bronchiolitis obliterans-organizing pneumonia, bronchocentric granulomatosis, bronchogenic cyst, bronchopneumonia, bronchopulmonary dysplasia, bronchopulmonary sequestration, bullae, bullous emphysema, cancer, carcinoid tumors, carcinoma of the lung (bronchogenic carcinoma), central (bronchogenic) carcinoma, central cyanosis, centriacinar emphysema, cetrilobular emphysema, chest pain, Chlamydial pneumonia, chondroid hamartoma, chronic airflow obstruction, chronic bronchitis, chronic diffuse interstitial lung disease, chronic idiopathic pulmonary fibrosis, chronic lung abscess, chronic radiation pneumonitis, chronic obstructive pulmonary diseases, chronic silicosis, chylothorax, ciliary dyskinesia, coal worker's pneumoconiosis (anthracosis), coccidioidomycosis, collagen-vascular diseases, common cold, compensatory emphysema, congenital acinar dysplasia, congenital alveolar capillary dysplasia, congenital bronchobiliary fistula, congenital bronchoesophageal fistula, congenital cystic adenomatoid malformation, congenital pulmonary lymphangiectasis, congenital pulmonary overinflation (congenital emphysema), congestion, cough, cryptococcosis, cyanosis, cystic fibrosis, cysticercosis, cytomegalovirus, desquamative interstitial pneumonitis, destructive lung disease, diatomaceous earth pneumoconiosis, diffuse alveolar damage, diffuse pulmonary haemorrhage, diffuse septal amyloidosis, difuse panbronchiolitis, Dirofilaria immitis, diseases of the pleura, distal acinar (paraceptal) emphysema, drug-induced asthma, drug- induced diffuse alveolar damage, dyspnea, ectopic hormone syndromes, emphysema, empyemma, eosinophilic pneumonias, exercise-induced asthma, extralobar sequestration, extrinsic allergic asthma, fat emboli, focal dust emphysema, follicular bronchiolitis, follicular bronchitis, foreign-body embolism, Fuller's earth pneumoconiosis, functional resistance to arterial flow (vasoconstriction), fungal granulomas of the lung, fungal infections, Goodpasture's syndrome, graphite pneumoconiosis, gray hepatization, hamartomas, hard metal disease, hemoptysis, hemothorax, herniation of lung tissue, herpes simplex, heterotopic tissues, high-altitude pulmonary edema, histoplasmosis, horseshoe lung, humidifier fever, hyaline membrane disease, hydatid cysts, hydrothorax, hypersensitivity pneumonitis (extrinsic allergic alveolitis), hypoxic vascular remodeling, iatrogenic drug-, chemical-, or radiation-induced interstitial fibrosis, idiopathic interstitial pneumonia, idiopathic organizing pneumonia, idiopathic pulmonary fibrosis (fibrosing alveolitis, Hamman-Rich syndrome, acute interstitial pneumonia), idiopathic pulmonary hemosiderosis, immunologic interstitial fibrosis, immunologic interstitial pneumonitis, immunologic lung disease, infections causing chronic granulomatous inflammation, infections causing chronic suppurative inflammation, infections of the air passages, infiltrative lung disease, inflammatory lesions, inflammatory pseudotumors, influenza, interstitial diseases of uncertain etiology, interstitial lung disease, interstitial pneumonitis in connective tissue diseases, intralobar sequestration of the lung (congenital), intrinsic (nonallergic) asthma, invasive pulmonary aspergiUosis, kaolin pneumoconiosis, Kartagner's syndrome, Klebsiella pneumonia, Langerhans' cell histiocytosis (histiocytosis X), large cell undifferentiated carcinoma, larval migration of Ascaris lumbricoides, larval migration of Strongyloides stercoralis, left pulmonary artery "sling", Legionella pneumonia, lipid pneumonia, lobar pneumonia, localized emphysema, long-standing bronchial obstruction, lung abscess, lung collapse, lung fluke, lung transplantation implantation response, lymphangiomyomatosis, lymphocytic interstitial pneumonitis (pseudolymphoma, lymphoma, lymphomatoid granulomatosis, malignant mesothelioma, massive pulmonary hemorrhage in the newborn, measles, meconium aspiration syndrome, mesenchymal cystic hamartomas, mesenchymal tumors, mesothelioma, metal-induced lung diseases, metastatic calcification, metastatic neoplasms, metastatic ossification, mica pneumoconiosis, mixed dust fibrosis, mixed epithelial-mesenchymal tumors, mixed type neoplasms, mucoepidermoid tumor, mucoviscidosis (fibrocystic disease of the pancreas), mycoplasma pneumoniae, necrotizing bacterial pneumonia, necrotizing sarcoid granulomatosis, neonatal respiratory distress syndrome, neoplasms of the pleura, neuromuscular syndromes, nocardiosis, nondestructive lung disease, North American blastomycosis, occupational asthma, organic dust disease, panacinar emphysema, Pancoast's syndrome, paracoccidioidomycosis, parainfluenza, paraneoplastic syndromes, paraseptal emphysema (paracicatricial), parasilicosis syndromes, parasitic infections of the lung, peripheral cyanosis, peripheral lung carcinoma, persistent pulmonary hypertension of the newborn, pleural effusion, pleural diseases, pleural plaques, pneumococcal pneumonia, pneumoconioses (inorganic dust diseases), Pneumocystis carinii pneumonia, pneumocystosis, pneumonitis, pneumothorax, precapillary pulmonary hypertension, primary (childhood) tuberculosis, primary (idiopathic) pulmonary hypertension, primary mesothelial neoplasms, primary pulmonary hypertensions, progressive massive fibrosis, psittacosis, pulmonary actinomycosis, pulmonary air-leak syndromes, pulmonary alveolar proteinosis, pulmonary arteriovenous malformation, pulmonary blastoma, pulmonary capillary hemangiomatosis, pulmonary carcinosarcoma, pulmonary edema, pulmonary embolism, pulmonary eosinophilia, pulmonary fibrosis, pulmonary hypertension, pulmonary hypoplasia, pulmonary infarction, pulmonary infiltration and eosinophilia, pulmonary interstitial air (pulmonary interstitial emphysema), pulmonary lesions, pulmonary nocardiosis, pulmonary parenchymal anomalies, pulmonary thromboembolism, pulmonary tuberculosis, pulmonary vascular disorders, pulmonary vasculitides, pulmonary veno-occlusive disease, pyothorax, radiation pneumonitis, recurrent pulmonary emboli, red hepatization, respiration failure, respiratory syncytial virus, Reye's syndrome, rheumatoid lung disease, Rickettsial pneumonia, rupture of pulmonary arteries, sarcoidosis, scar cancer, scimitar syndrome, scleroderma, sclerosing hemangioma, secondary (adult) tuberculosis, secondary bacterial pneumonia, secondary pleural neoplasms, secondary pulmonary hypertension, senile emphysema, siderosis, silicate pneumoconiosis asbestosis, silicatosis, silicosis, simple nodular silicosis, Sjδgren's syndrome, small airway lesions, small cell carcinoma, small cell undifferentiated (oat cell) carcinoma, spontaneous pneumothorax, sporotrichosis, sputum production, squamous (epidermoid) carcinoma, stannosis, staphlococcal pneumonia, suppuration (abscess formation), systemic lupus erythematosus, talcosis, tension pneumothorax, tracheal agenesis, tracheal stenosis, tracheobronchial amyloidosis, tracheobronchomegaly, tracheoesophageal fistula, transient tachypnea of the newborn (neonatal wet lung), tungsten carbide pneumoconiosis, usual interstitial pneumonia, usual interstitial pneumonitis, varicella, viral pneumonia, visceral pleural thickening, Wegener's granulomatosis, and whooping cough (pertussis). In embodiments, provided is a composition or nasal spray for use as defined herein, wherein the lung disease or disorder is selected from: (i) chronic obstructive pulmonary disease, emphysema, asthma, chronic obstructive pulmonary disease (COPD), chronic bronchitis, emphysema, and pulmonary hypertension, sarcoidosis, influenza, pneumonia, tuberculosis; (ii) pulmonary fibrosis, for example idiopathic pulmonary fibrosis, fibrotic interstitial lung disease, interstitial pneumonia, fibrotic variant of non- specific interstitial pneumonia, cystic fibrosis; and / or (iii) lung cancer and lung cancer asthma. Peptide modified polymer preparation The present invention provides methods for the preparation of the peptide modified polymers provided herein. In these methods, an amine is typically contacted with an alkene (i.e. a dialkene such as a diacrylate). As will be appreciated by one of ordinary skill in the art, it is possible to modify the nature of the amine and alkene freely to prepare a diverse range of peptide modified polymers that are suitable for use in the applications defined above. Preparation of linear peptide modified polymers In an aspect the present invention provides a method for preparing a peptide modified polymer as defined herein, the method comprising the steps of: (i) contacting an amine having the structure of Formula (I): H2N-R3, with an alkene having the structure of Formula (II): in an organic solvent; (ii) agitating and optionally heating the solution of step (i); (iii) contacting the reaction mixture with a peptide of Formula (VI): R1-H; and (iv) agitating the reaction mixture; to thereby prepare the peptide modified polymer; wherein each R1, R2, R9, L1, L2, X, and Y are as defined herein. In step (i), an amine of Formula (I) is contacted with an alkene having the structure of Formula (II), in an organic solvent. By contacted, it is to be understood that the compounds are combined in solution and are able to contact each other through normal movement in the solvent phase. It will be appreciated that the various compounds referred to in step (i) may be added in any order, or even simultaneously e.g. through the use of one or more syringe pumps. The order in which the features of step (i) are presented are therefore illustrative and non-limiting. In embodiments, separate stock solutions of the amine of Formula (I) and the alkene of Formula (II) are prepared. In embodiments, the concentrations of the stock solutions are from about 1 mg / mL to about 1000 mg / mL, from about 10 mg / mL to about 750 mg / mL, from about 25 mg / mL to about 500 mg / mL, from about 50 mg / mL to about 250 mg / mL, from about 100 mg / mL to about 200 mg / mL, from about 125 mg / mL to about 175 mg / mL, or from about 140 mg / mL to about 160 mg / mL. In embodiments, the concentration of the stock solutions are about 150 mg / mL. In embodiments, the stock solutions are combined to afford a solution comprising the amine of Formula (I) and the alkene of Formula (II). The resulting solution will accordingly comprise the alkene of Formula (II) and the amine of Formula (I) in a certain ratio. The ratio may be optimised to afford peptide modified polymers with optimal properties for the desired application as described herein. It will be appreciated that “ratio” in this context is intended to refer to the molar ratio of each component. In embodiments, the ratio of the alkene of Formula (II) to the amine of Formula (I) is about 5.0 to about 1.0, about 4.0 to about 1.0, about 3.0 to about 1.0, about 2.0 to about 1.0, about 1.9 to about 1.0, about 1.8 to about 1.0, about 1.7 to about 1.0, about 1.6 to about 1.0, about 1.5 to about 1.0, about 1.4 to about 1.0, about 1.3 to about 1.0, about 1.2 to about 1.0, about 1.15 to about 1.0, about 1.1 to about 1.0, about 1.09 to about 1.0, about 1.08 to about 1.0, about 1.07 to about 1.0, about 1.06 to about 1.0, about 1.05 to about 1.0, about 1.04 to about 1.0, about 1.03 to about 1.0, about 1.02 to about 1.0, about 1.01 to about 1.0. In embodiments, the ratio of the alkene of Formula (II) to the amine of Formula (I) is about 1.5 to about 1.0, preferably from about 1.2 to about 1.0 or from about 1.05 to about 1.0. In embodiments, the ratio of the alkene of Formula (II) to the amine of Formula (I) is about 1.2 to about 1.0. In embodiments, the ratio of the alkene of Formula (II) to the amine of Formula (I) is about 1.05 to about 1.0. The method conveniently takes place in solution (see e.g. step (iv), above). In embodiments, the solvent is an organic solvent, for example an aprotic organic solvent. In embodiments, the organic solvent is selected from tetrahydrofuran (THF), 2- methyltetrahydrofuran, dioxane, ethyl acetate (EtOAc), acetone, dimethylformamide (DMF), acetonitrile (MeCN), dichloroethane (DCE), dichloromethane (DCM), chloroform, dimethyl sulfoxide (DMSO), and toluene. In embodiments, the organic solvent is selected from: DMSO, DMF, and THF. In embodiments, the reaction mixture of step (ii) is agitated. In embodiments, agitating is achieved using an agitating means. In embodiments, the agitating means is a stirring means. In embodiment the stirring means is selected from: a stirrer plate, a magnetic stirrer, an Ika®hotplate and a mechanical stirrer such as e.g. an overhead stirrer. As one of ordinary skill in the art will appreciate, methods of synthesising peptide modified polymers that are homogeneous are particularly advantageous. The methods of the present invention afford homogenous peptide modified polymers. In embodiments, the stirring means stirs the reaction mixture at a particular rate, e.g. a rate measured in revolutions per minute (rpm). In embodiments, the rate is about 1 rpm to about 5000 rpm, about 100 rpm to about 5000 rpm, about 200 rpm to about 4000 rpm, about 400 rpm to about 2000 rpm, about 600 rpm to about 1000 rpm, about 700 rpm to about 900 rpm, or about 750 rpm to about 850 rpm. In embodiments, the rate is about 800 rpm. It should be understood by a person of ordinary skill in the art that the terms “solution” and “reaction mixture” are to be interpreted as being interchangeable. For example, the above embodiments relating to stirring means and rate apply equally to the organic solvent solution of step (i) as they do to the reaction mixture of step (iv). In embodiments, the reaction mixture of step (ii) is heated. In embodiments, the reaction mixture is heated at about 20 °C to about 190 °C, about 30 °C to about 170 °C, about 40 °C to about 150 °C, about 50 °C to about 130 °C, about 60 °C to about 120 °C, about 70 °C to about 110 °C, or about 80 °C to about 100 °C, e.g. about 90 °C. In embodiments, the reaction mixture of step (ii) is heated at about 90 °C. In embodiments, the reaction mixture of step (ii) is allowed to react for a time period i.e. a reaction time. In embodiments, the time period is about 168 h, about 144 h, about 120 h, about 96 h, about 72 h, about 48 h, about 24 h, about 16 h, about 12 h, about 6 h, about 3 h, or about 1 h. In embodiments, the time period is about 48 h. In embodiments, the reaction mixture of step (ii) is protected from light. In embodiments, the reaction mixture of step (ii) is protected from light while reacting for a time period defined herein. In embodiments, the reaction mixture of step (ii) is protected from light using e.g. foil. In step (iii), the reaction mixture is contacted with a peptide of Formula (VI). The purpose of this step is to end cap the polymer to form a peptide modified polymer. In this step, a conjugate (Michael) addition reaction occurs between the terminal acrylate (alkene) and a nucleophilic moiety of the peptide of Formula (VI). The nucleophilic moiety may conveniently be a nitrogen atom e.g. of the N-terminus of the peptide. This reaction mechanism is similar to that of step (ii) in which the amine of Formula (I) undergoes a conjugate (Michael) addition reaction with the alkene of Formula (II). In embodiments, the reaction mixture of step (ii) is allowed to cool before the peptide of Formula (VI) is added in step (iii). In embodiments, the reaction mixture is allowed to cool to room temperature. In embodiments, the reaction mixture is allowed to cool to the temperature used in step (iii) as defined herein, e.g. room temperature or 30 °C. In step (iii), the peptide of Formula (VI) is added to the reaction mixture. In embodiments, an excess of the peptide of Formula (VI) is added relative to the limiting reagent of step (i). In embodiments, the limiting reagent is the amine of Formula (I). In embodiments, about 10 equivalents, about 9 equivalents, about 8 equivalents, about 7 equivalents, about 6 equivalents, about 5 equivalents, about 4 equivalents, about 3 equivalents, about 2 equivalents, about 1.8 equivalents, about 1.6 equivalents, about 1.4 equivalents, about 1.2 equivalents, about 1.1 equivalents, or about 1.05 equivalents of the peptide of Formula (VI) is used relative to the amount of the amine of Formula (I). In embodiments, about 2 equivalents of the peptide of Formula (VI) is used relative to the amount of the amine of Formula (I). In embodiments, the peptide of Formula (VI) is added neat to the reaction mixture. In other embodiments, the peptide of Formula (VI) is added to the reaction mixture in solution. The solvent may, for example, be any of the organic solvents defined herein. In other embodiments, the solvent is water, e.g. deionised water. In embodiments, the peptide of Formula (VI) is added to the reaction mixture in a solution which comprises more than one solvent. In embodiments, the more than one solvent is DMF and water. In embodiments, the peptide of Formula (VI) is dissolved in a first solvent, e.g. water, and then diluted with a second solvent such as an organic solvent e.g. DMF. In embodiments, the dilution with the second solvent is stopped if precipitation is observed. In step (iv), the reaction mixture is agitated. The reaction mixture may be agitated using any of the agitation means, and any of the stirring rates described above. In embodiments, the reaction mixture of step (iv) is stirred at about 500 rpm. In embodiments, the reaction mixture of step (iv) is heated. In embodiments, the reaction mixture is heated at about 20 °C to about 100 °C, about 20 °C to about 80 °C, about 20 °C to about 60 °C, about 20 °C to about 50 °C, about 25 °C to about 45 °C, about 25 °C to about 40 °C, or about 25 °C to about 35 °C, for example about 30 °C. In embodiments, the reaction mixture of step (iv) is heated at about 20 °C to about 60 °C, preferably about 25 °C to about 40 °C, for example about 30 °C. In embodiments, the reaction mixture is heated at room temperature. In embodiments, the reaction mixture is heated at about 30 °C. In embodiments, the reaction mixture of step (iv) is allowed to react for a time period i.e. a reaction time. In embodiments, the time period is about 168 h, about 144 h, about 120 h, about 96 h, about 72 h, about 48 h, about 24 h, about 16 h, about 12 h, about 6 h, about 3 h, or about 1 h. In embodiments, the time period is about 6 h. Step (iii) is conveniently performed in the presence of a base. In embodiments, the base is an organic base. In embodiments, the organic base is selected from one or more of triethylamine, trimethyl amine, isopropyl ethylamine, diisopropyl amine (iPr2NH), diisopropylethylamine, N-methylpiperidine, piperidine, pyridine, 3-methylpyridine, pyrrole, tributyl amine, 4-dimethylaminopyridine, N-methyl morpholine, N-methylpyrrolidine, pyrrolidine, 1-methylimidazole, imidazole, 3- methylpyrrazole, pyrazole, and 1-methylimidazole (N-methylimidazole). In embodiments, the organic base is selected from one of triethylamine, trimethyl amine, isopropyl ethylamine, diisopropyl amine (iPr2NH), diisopropylethylamine, N-methylpiperidine, piperidine, pyridine, 3-methylpyridine, pyrrole, tributyl amine, 4-dimethylaminopyridine, N- methyl morpholine, N-methylpyrrolidine, pyrrolidine, 1-methylimidazole, imidazole, 3- methylpyrrazole, pyrazole, and 1-methylimidazole (N-methylimidazole). In embodiments, the organic base is selected from one or more of iPr2NH, 1-methylimidazole, and morpholine. In embodiments, the organic base is triethylamine. In embodiments, the base is an inorganic base. In embodiments, the inorganic base is selected from one or more of alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide; alkali metal alkoxides such as sodium tert- butoxide, potassium tert-butoxide; alkali metal carbonates such as sodium carbonate, potassium carbonate; and alkali metal bicarbonates such as sodium bicarbonate and potassium bicarbonate. In an embodiment the inorganic base is selected from alkali metal carbonates such as sodium carbonate, potassium carbonate; and alkali metal bicarbonates such as sodium bicarbonate and potassium bicarbonate. As the skilled person will appreciate, the organic and inorganic bases presented above are not limiting and are simply illustrative of bases that are suitable for use in the methods of the invention. In step (iii), if a base is added then it may be advantageous to use an excess of the base. In embodiments, an excess of base is added relative to the limiting reagent of step (i) . In embodiments, the limiting reagent is the amine of Formula (I). In embodiments, about 10 equivalents, about 9 equivalents, about 8 equivalents, about 7 equivalents, about 6 equivalents, about 5 equivalents, about 4 equivalents, about 3 equivalents, about 2 equivalents, about 1.8 equivalents, about 1.6 equivalents, about 1.4 equivalents, about 1.2 equivalents, about 1.1 equivalents, or about 1.05 equivalents of base is used relative to the amount of the amine of Formula (I). In embodiments, about 2 equivalents of base is used relative to the amount of the amine of Formula (I). Advantageously, the use of a base in step (iii) enables shorter reaction times and increased yields of the peptide modified polymers. Preparation of branched peptide modified polymers As will be appreciated by a person of ordinary skill in the art, it is also possible to synthesise mixed peptide modified polymers in which two or more amines of different structures are contacted with the alkene. If one of those amines is a diamine, then it is possible to form branched peptide modified polymers. Branched peptide modified polymers have many useful properties, for example increased density of peptide end cap groups enable fine tuning of the bulk properties of the polymer. If the peptide modified polymer backbone is hydrophobic but the end cap groups are polar / hydrophilic peptides, this can result in increased solubility in aqueous media useful during formulation. Branching can also result in changes to the viscosity of the peptide modified polymer. Accordingly, methods of producing these polymers are particularly advantageous. In other words, in embodiments, the present invention provides a method as defined herein, the method comprising the steps of: (i) contacting an amine having the structure of Formula (I): H2N-R3, with an alkene having the structure of Formula (II): an amine selected from: Formula (III): , Formula (IV): Formula (V): ; in an organic solvent; (ii) agitating and optionally heating the solution of step (i); (iii) contacting the reaction mixture with a peptide of Formula (VI): R1-H; and (iv) agitating the reaction mixture; to thereby prepare the peptide modified polymer; wherein each R1, R2, R9, L1, L2, X, and Y are as defined herein. One of ordinary skill in the art will appreciate that step (i) to the extent it includes contacting an amine selected from: Formula (III): , Formula (IV): , and Formula (V): with the amine of Formula (I) and the alkene of Formula (III), will result in the formation of peptide modified polymers that have a branched structure. This is because each amine may act as a branching point in the peptide modified polymer. In other embodiments, the amine used in step (i) is NH3. In step (i), an amine of Formula (I) is contacted with an alkene having the structure of Formula (II) and an amine selected from Formula (III), (IV), and (V), in an organic solvent. By contacted, it is to be understood that the compounds are combined in solution and are able to contact each other through normal movement in the solvent phase. It will be appreciated that the various compounds referred to in steps (i) to (iii) may be added in any order, or even simultaneously e.g. through the use of one or more syringe pumps. The order in which the features of step (i) are presented is illustrative and non-limiting. It will be appreciated by a person of ordinary skill in the art that the above embodiments relating without limitation to: stock solutions, concentrations, ratios, solvent, agitation, stirring rate, heating temperature, time period, protection from light, cooling, equivalents of e.g. peptide of Formula (VI), methods of adding the peptide of Formula (VI) to the reaction mixture, use of base, and equivalents, are to be understood as applicable to methods defined herein of making branched peptide modified polymers. In embodiments, the amine having the structure of Formula (I) is selected from: In embodiments, the alkene having the structure of Formula (II) is selected from: ethylene glycol) diacrylate). In embodiments, the amine having the structure of Formula (IV) is In embodiments, the peptide having the structure of Formula (VI) is selected from: In embodiments, the peptide having the structure of Formula (VI) is selected from:

[0019] Preparation of peptide modified polymers comprising an L3linker Peptide modified polymers of the type described herein in which R1is a radical defined by the structure: may be provided by the methods outlined below. Accordingly, provided is a method for preparing a peptide modified polymer as defined herein, the method comprising the steps of: (i) contacting an amine having the structure of Formula (I): H2N-R3, with an alkene having the structure of Formula (II): in an organic solvent; (ii) agitating and optionally heating the solution of step (i); (iii) contacting the reaction mixture with 5-norbornene-2-methylamine; (iv) agitating and optionally heating the solution of step (iii); (v) contacting the product of step (iv) with a photoinitiator and a peptide of Formula (VI): R1-H in an organic solvent, wherein R1is a peptide; (vi) agitating and irradiating the solution of step (v); to thereby prepare the peptide modified polymer; wherein each R1, R2, R9, L1, L2, L3, X, and Y are as defined herein. A person of ordinary skill in the art will appreciate that experimental variables in the above procedure may be varied as described above. For example, order of reagents being contacted with each other, the use of stock solutions (e.g. of particular concentrations), the ratio of the alkene of Formula (II) to the amine of Formula (I), the organic solvent, agitation means, heating, reacting for a time period, the ratio of the peptide of Formula (VI) to the amine of Formula (I), and the solvent. In embodiments, the reaction mixture of step (iv) is allowed to react for a time period. In embodiments, the time period is about 24 h. In embodiments, the reaction mixture of step (iv) is heated. In embodiments, the reaction mixture of step (iv) is heated at about 90 °C. In embodiments, the product of step (iv) is obtained before step (v) is performed, for example by precipitation such as by cold diethyl either. The precipitated product of step (iv) may be re-dissolved in an organic solvent (e.g. DMSO), before being subjected to step (v). In embodiments, the photoinitiator is used at a concentration of 0.1 mol%. In embodiments, the photoinitiator is Irgacure2959, Sigma, 410896. In embodiments, the ratio of the peptide of Formula (VI) to 5-norbornene-2- methylamine is about 1.2 to about 1.0. In embodiments, the irradiating takes place in a plastic tube such as a polypropylene tube. In embodiments, the irradiating is with a UV light source. An example source may be mW / cm2. The reaction mixture may be irradiated for a time period of about 10 minutes, about 8 minutes, about 6 minutes, about 5 minutes, about 4 minutes, or about 3 minutes. The reaction mixture may be irradiated for about 3 minutes. In embodiment, a) R1comprises one or more Cys (C) amino acids; and / or b) the irradiating is with a UV light source. It will be appreciated by one of ordinary skill in the art that any of the radical species formulae defined above, e.g. Formula (A), (B), (C), (D), (B-I), (D-I), substituents thereof, and formulae referring to fragments thereof, are also intended to refer to corresponding compounds that may be used as starting materials in the methods defined herein. Product isolation The peptide modified polymer of any of the methods defined herein may be isolated using a number of means that will be known to those of ordinary skill in the art. In embodiments, ether, e.g. diethyl ether is added to the reaction mixture of step (vii) in order to induce precipitation of the peptide modified polymer. In embodiments, the peptide modified polymer is re-dissolved in an organic solvent e.g. DMF, following precipitation in ether. In embodiments, the re-dissolved product is then filtered through a filter. In embodiments, the filter is a PTFE filter, e.g. a 0.45 micron PTFE filter. In embodiments, further diethyl ether is added to the filtrate to induce precipitation, and the product is collected by centrifuge. In embodiments, the product is dried under vacuum for a time period e.g. about 24 to about 48 h. In embodiments, the isolation procedure comprises one or more of the above steps, for example all of the above. In other embodiments, the reaction mixture of step (vii) is added dropwise to ether, e.g. diethyl ether. In embodiments, 10 volumes of ether are used relative to the volume of the reaction mixture of step (vii). In embodiments, the ether is cooled to below room temperature, e.g. to 0 °C. In embodiments, the ether is spiked with glacial acetic acid, e.g. at a concentration of about 5 µL glacial acetic acid per 100 mg theoretical yield of peptide modified polymer. In embodiments, the resulting solution is vortexed. In embodiments, the solution is decanted from the precipitate (peptide modified polymer product). In embodiments, the product is dried under vacuum for a time period e.g. about 24 to about 48 h. In embodiments, the isolation procedure comprises one or more of the above steps, for example all of the above. Preparation of nanoparticle compositions Advantageously, the peptide modified polymers of the present invention may be used to prepare nanoparticle compositions. These nanoparticle compositions have many useful applications, e.g. they can be used to deliver polynucleotides in vivo. Accordingly, in embodiments, the present invention provides a method for preparing a nanoparticle composition as defined herein, the method comprising the steps of: (i) providing the peptide modified polymer as defined herein in an organic solvent; (ii) combining the organic solvent with an aqueous buffer; (iii) suspending a polynucleotide in water or an aqueous buffer, for example a sodium citrate buffer or phosphate-buffered saline (PBS); (iv) combining the mixture produced by step (ii) with the mixture produced by step (iii); to thereby prepare the nanoparticle composition. In embodiments, the peptide modified polymer is a peptide modified polymer defined herein and / or produced by the methods defined herein. In embodiments, the organic solvent is an organic solvent, for example an aprotic organic solvent. In embodiments, the organic solvent is selected from tetrahydrofuran (THF), 2-methyltetrahydrofuran, dioxane, ethyl acetate (EtOAc), acetone, dimethylformamide (DMF), acetonitrile (MeCN), dichloroethane (DCE), dichloromethane (DCM), chloroform, dimethyl sulfoxide (DMSO), and toluene. In embodiments, the organic solvent is DMSO. In embodiments, the peptide modified polymer is dissolved in the organic solvent at a concentration selected from: about 0.1 mg / mL to about 1000 mg / mL, about 1 mg / mL to about 500 mg / mL, about 2 mg / mL to about 400 mg / mL, about 3 mg / mL to about 300 mg / mL, about 4 mg / mL to about 250 mg / mL, about 4 mg / mL to about 200 mg / mL, about 5 mg / mL to about 180 mg / mL, about 6 mg / mL to about 160 mg / mL, about 7 mg / mL to about 140 mg / mL, about 8 mg / mL to about 120 mg / mL, about 9 mg / mL to about 110 mg / mL, about 10 mg / mL to about 100 mg / mL. In embodiments, the concentration is about 10 mg / mL to about 100 mg / mL. In step (ii), the organic solvent mixture is combined with an aqueous buffer. Typically, the aqueous buffer is a salt prepared from an organic acid or base. Representative aqueous buffers include organic acid salts such as salts of citric acid, ascorbic acid, gluconic acid, carbonic acid, tartaric acid, succinic acid, acetic acid, or phthalic acid; Tris, tromethamine hydrochloride, or phosphate buffers. In embodiments, the aqueous buffer is selected from sodium acetate, sodium citrate or phosphate buffered saline (PBS) buffer. A polynucleotide is suspended in water or an aqueous buffer in step (iii). In embodiments, the buffer of step (iii) is the same as the buffer of step (ii). In other embodiments, the buffer of step (iii) is not the same as the buffer of step (ii). In embodiments, the aqueous buffer of step (iii) is selected from sodium citrate or phosphate buffered saline (PBS) buffer. In embodiments, the polynucleotide is selected from DNA and RNA. In embodiments, the RNA is mRNA, ssRNA, circRNA, dsRNA, saRNA, siRNA, shRNA, or miRNA. In embodiments, the RNA is mRNA. In embodiments, more than one polynucleotide is used to prepare the nanoparticle composition. In step (iv), the two aqueous solutions are combined. In embodiments, the solutions are combined by pipetting or by microfluidic mixing. In embodiments, an excess of peptide modified polymer to polynucleotide is used. The use of an excess of peptide modified polymer enables as much polynucleotide to be delivered in vivo as possible. This is particularly advantageous because it is often the polynucleotide which is the most expensive component of the nanoparticle compositions. Additionally, in pharmaceutical applications it is important that the dose of the polynucleotide delivered to the cells is capable of being controlled as much as possible. Ideally, as high an amount of the polynucleotide as possible is delivered to the cells to avoid undesired side effects in the body from having to metabolise and excrete excess polynucleotide that is not capable of being delivered to the target cells. In embodiments, the ratio of peptide modified polymer to polynucleotide is about 200 to about 1, about 100 to about 1, about 80 to about 1, about 60 to about 1, about 50 to about 1, about 40 to about 1, about 30 to about 1, about 20 to about 1, about 10 to about 1, about 9 to about 1, about 8 to about 1, about 7 to about 1, about 6 to about 1, or about 5 to about 1. In embodiments, the ratio of peptide modified polymer to polynucleotide is about 5 to about 1. In embodiments, the ratio of peptide modified polymer to polynucleotide is about 400 to about 1, about 300 to about 1, about 250 to about 1, about 200 to about 1, about 180 to about 1, about 160 to about 1, about 140 to about 1, about 120 to about 1, about 100 to about 1, about 90 to about 1, about 80 to about 1, about 70 to about 1, about 60 to about 1, or about 50 to about 1. In embodiments, the ratio of peptide modified polymer to polynucleotide is about 50 to about 1. In embodiments, the ratio of peptide modified polymer to polynucleotide is from about 50 to about 1 to about 5 to about 1. Advantageously, the methods of the present invention may be used to prepare peptide modified polymers with optimal properties for use in the applications described herein. For example, varying the ratio of alkene of Formula (II) to the amine of Formula (I) affords peptide modified polymers of varying average molecular weight (in other words, of varying lengths) that are suited to the desired application. For example, using lower ratios of the alkene of Formula (II) to the amine of Formula (I) results in higher molecular weight peptide modified polymers (i.e. those with longer chain lengths) which may conveniently be used to form nanoparticle compositions with longer polynucleotides, such as saRNA. Accordingly, in embodiments, the ratio of the alkene of Formula (II) to the amine of Formula (I) is about 1.05 to about 1.0, and the polynucleotide is a long length RNA, e.g. saRNA. The opposite is the case when higher ratios of the alkene of Formula (II) to the amine of Formula (I) are used since this results in lower molecular weight peptide modified polymers (i.e. those with shorter chain lengths) which may conveniently be used to form nanoparticle compositions with shorter polynucleotides, such as siRNA and miRNA. Accordingly, in embodiments, the ratio of the alkene of Formula (II) to the amine of Formula (I) is about 1.2 to about 1.0, and the polynucleotide is siRNA. Further, use of the ratio of the alkene of Formula (II) to the amine of Formula (I) of about 1.2 to about 1.0 advantageously results in shorter length peptide modified polymers that may be used to form nanoparticles with reduced toxicity in vivo and increased aqueous solubility. Increased aqueous solubility is particularly beneficial when the polynucleotide is RNA and higher concentrations are used for in vivo delivery. This makes these nanoparticles easier to formulate. In other embodiments, step (iv) is omitted and a nanoparticle composition is prepared without a polynucleotide. Having been generally described herein, the follow non-limiting examples are provided to further illustrate this invention. EXAMPLES General information and instrumentation Commercial reagents were used as supplied. Nuclear magnetic resonance spectra were recorded on 400 MHz spectrometers. Chemical shifts for1H NMR spectra are recorded in parts per million from tetramethylsilane with the solvent resonance as the internal standard (CHCl3: δ= 7.27 ppm, H2O: δ=4.79 ppm, DMSO: δ= 2.50 ppm). Particle size as z-average mean diameter and ζ-potential were determined by DLS analysis of aqueous suspensions performed at 25°C using a Malvern Zetasizer Ultra instrument. For size analysis, samples were prepared by diluting nanoparticle dispersions 1 in 10 with the appropriate dispersant (1 mL). Measurements were performed using polystyrene cuvettes at 25 °C, measuring the scattered light at an angle of 173°. The samples were then transferred to a folded capillary cell for ζ-potential determination, performing the measurements at 25 °C. Nanoparticles were imaged directly using a JEM-2100Plus transmission electron microscope. Example 1 – Synthesis of peptide modified polymers In this example, peptide modified polymers of the invention are prepared. The first peptide modified polymer, “A24-GlySar” comprises a hydrophilic backbone and GlySar peptide endcaps. A24-GlySar synthesis Key: Diacrylate “A” = Di(ethylene glycol) diacrylate Amine “24” = (±)-3-Amino-1,2-propanediol Dipeptide: Glycyl-sarcosine, 146.14 g / mol, 29816-01-1 Method: 1. Monomer stock solutions were prepared by weighing A and 24 and dissolving in anhydrous DMF separately, to a final concentration of 150 mg / mL. 2. A and 24 were mixed at different molar ratios, 1.05:1 or 1.2:1, diacrylate to amine. 3. A stirrer bar was added and the reaction mixture was heated at 90 °C for 48 h, on a heated stir plate. The reaction mixture was protected from light. 4. An aliquot of 100 µL was removed from the reaction solution and precipitated by ether for analysis by NMR. The NMR (proton) is shown in FIG.1A. 5. Gly-Sar (2 eq.) was dissolved in water (half the volume of DMF) and 2 eq. TEA (triethylamine) was added. 6. The reaction mixture was reacted for 6 h at room temperature. 7. The polymer was precipitated in ether until the lower layer of yellow liquid turned into a viscous solid. 8. The polymer was re-dissolved in anhydrous DMF and filtered through 0.45 micron PTFE filter. 9. The polymer was precipitated in anhydrous diethyl ether and the solid was collected by centrifuge. 10. The solvent was decanted. 11. The solid was dried under vacuum for 24 – 48 hours. The NMR (proton) is shown in FIG.1B. The second peptide modified polymer, “DD90-GlySar” comprises a hydrophobic backbone and GlySar peptide endcaps. DD90-GlySar synthesis Key: Diacrylate DD = Bisphenol A glycerolate (1 glycerol / phenol diacrylate) (484.54 g / mol Cas 1194687-94-9) Hydrophilic amine 90 = 4-(2-Aminoethyl)morpholine (130.19 g / mol, Cas 2038-03-1) Solvent = Anhydrous dimethylformamide (Sigma-Aldrich, 227056) Day 1 – DD-90-Ac Synthesis: 1. Two 4 mL glass scintillation vials were prepared with stir bars (vial A and B) 2. To vials, was added: a. DD = 313 mg b.1.92 mL of DMF c.90 = 70.65 µL 3. The vials were covered with foil and stirred on a medium setting (800 RPM) at 90 °C for 48 hours. 4. After 24 hours, a golden, viscous solution was observed. Day 2: End cap polymer Materials: Dipeptide end cap Gly-Sar = Glycyl-sarcosine (146.14 g / mol, 29816-01-1) Method: 1. The DD90-Ac vial was removed from heat and cooled to room temperature. 2. An aliquot of 100 µL was taken for NMR analysis. 3. The reaction temperature was reduced to 30 °C. 4.78.67 mg of peptide end cap (Gly-Sar) was dissolved in 1.15 mL deionized water. 5. The Gly-Sar solution was diluted slowly with 1.55 mL DMF to a final concentration of 100 mg mL-1. N.B. the addition of DMF should be stopped if precipitation is observed. 6. The Gly-Sar solution was added dropwise to the DD90-Ac solution while stirring at a high setting (800 RPM). 7. The reaction mixture was stirred at 30 °C on a low setting (500 rpm) for 6 hours. Day 2 / 3: Precipitation Materials: Anhydrous diethyl ether (Sigma-Aldrich, 296082) Glacial acetic acid (Sigma-Aldrich, 338826) Method: 1. A clean, empty glass dish was weighed and the weight recorded. 2. A 50 µL sample of end-capped polymer was retained for NMR analysis 3. The polymer was added dropwise to x10 volume of cold diethyl ether spiked with 14.5 µL glacial acetic acid (10 µL per 100 mg polymer) and vortexed. 4. The purified polymer was allowed to precipitate to the bottom of the tube. The ether was carefully decanted off. The procedure was repeated x2 with diethyl ether. The solid sample was transferred to a glass dish. 5. The polymer was dried under vacuum for 24 hours. Day 4: Collection 6. A 7 mg sample of end-capped polymer was retained for NMR analysis. The NMR (proton) is shown in FIG.2. 7. Remaining polymer was stored at -80°C A further peptide modified polymer, “DD90-AlaLys” was prepared using bisphenol A glycerolate “DD”, 4-(2-Aminoethyl)morpholine “90”, and AlaLys peptide following an analogous procedure. The proton NMR of the product peptide modified polymer is shown in FIG.3. Example 2 – Characterisation of peptide modified polymers In this example, the encapsulation of mRNA using peptide modified polymers was investigated. In addition, a control polymer (“DD90-118”) with the same backbone as the peptide modified polymers “DD90-GlySar” and “DD90-AlaLys” was used to compare the effect of incorporating peptide end caps. 118 is used to denote 1,5 diamino-2- methylpentane (CAS: 15520-10-2). 1% Agarose gels with RNA dye were loaded 20 μL per lane with 200 ng naked mRNA (not complexed), or complexed with uncapped DD90 backbone or complexed with peptide or amine end capped DD90, along with RiboRuler RNA ladder, the gel was run for 30 minutes in TAE buffer at 70 V. The retardation of mRNA movement during electrophoresis was observed for all end-capped PBAEs. A faint band was observed for uncapped DD90, and naked mRNA was not impeded. The results are shown in FIG.4A. A ribogreen assay (FIG.4B) was performed to determine the amount of mRNA not complexed with the peptide modified polymer by centrifuging complexed or non- complexed mRNA at 12,000 G for 5 minutes and assay the supernatant for free-mRNA. All peptide modified polymers were observed to efficiently encapsulate mRNA apart from uncapped DD90. Example 3 – Characterisation of PEPT2 in human lung cells Air-liquid interface culture of human bronchial epithelial cells (HBECs) Primary HBECs isolated from human donors or immortalised HBECs (iHBECs) were characterised by confirming expression of KRT5 for basal cells or SCGB1A1 as an indicator of differentiation. Basal HBECs were seeded between 15,000 – 30,000 cells per transwell insert in a 48 or 24 well plate, cells were grown in submerged conditions until confluent upon which the apical media was removed to expose the cells to air and promote differentiation to ciliated, non-ciliated and secretory lung epithelial cell sub-types. Cells were cultured at the air-liquid interface from 1 to 30 days. Expression of PEPT2 at gene level (SLC15A2) was characterised using qPCR and it was found that expression is upregulated from 7 days post-airlift (FIG. 5a). Protein expression of the receptor apically was confirmed using wholemount imaging using PEPT2 antibody staining and it was observed that the PEPT2 receptor is expressed apically and on the cell surface at 7 days post airlift. When HBECs are submerged, the transporter staining is constricted to the nucleus. (FIG.5b and 5c). Model ligand, AlaLys-AMCA, uptake in human ALI of HBECs Characterisation of PEPT2 receptor protein expression and corresponding SLC15A2 gene expression confirmed that this receptor can be adequately modelled in vitro using air-liquid interface culture. Increased gene expression and apical localisation of the protein was observed when human bronchial epithelial cells were differentiated at air-liquid interface compared to submerged cells. Uptake of a model peptide conjugated to a fluorophore (Ala-Lys-AMCA) showed that dose dependent increase in fluorescence is observed at ALI but not in submerged cultures (FIG.5d). Example 4 – mRNA transfection of ALI vs submerged HBECs using peptide modified materials mRNA encoding firefly luciferase (fluc) was complexed with DD90-118 or DD90- GlySar at a mass ratio of 50:1 or 20:1 (polymer to mRNA), the polyplexes were formulated in sodium acetate buffer (pH 5), sodium citrate (pH 5-7) or phosphate buffered saline (PBS, pH 7.4) and applied apically to ALI cultures of primary HBECs. Improved transfection of ALI at 7 and 14 days was observed with the peptide modified PBAE (FIG. 6). Luminescence was measured 24 – 48 hours after transfection. n = 3 primary donors and 3 technical repeats. It was found that the dipeptide must be conjugated to the polymer backbone to facilitate effective mRNA delivery. This was demonstrated by the low efficacy observed when fluc mRNA was delivered to HBECs using the DD90 uncapped polymer and free dipeptides added to the formulation (FIG.7a). When a hydrophilic PBAE such as A24-GlySar was formulated with mRNA, it was either used alone or was blended with DD90-118. For example in a 50:1 mass ratio of PBAE:mRNA mass, a blend of 45:5:1 DD90-118:A24-GlySar:mRNA may be used. Or 49:1:1 or 40:10:1 or 10:40:1. This could for example be scaled down for overall mass ratio of 20:1. While investigating A24-glysar transfection in ALI, iHBECs were air-lifted for 7 days and then a blend of mRNA complexed with A24-glysar and DD90-118 was applied. The results were compared to DD90-GlySar alone. Both were more effective at ALI transfection compared to DD90-118 alone (FIG.7b). Example 5 – Preparation of nanoparticles Peptide modified polymers prepared according to Example 1 were dissolved in DMSO at a concentration of 10 – 100 mg / mL and then diluted into an appropriate buffer such as sodium acetate, sodium citrate or phosphate buffered saline (PBS). The mRNA was present in a sodium citrate buffer, PBS or water. Appropriate dilutions of stock solutions were made such that the peptide modified polymer and mRNA were mixed by pipetting or by microfluidic mixing to achieve mass ratios between 5:1 to 50:1 polymer:mRNA. Example 6 – Particle properties of PBAE-peptide RNA polyplexes Dynamic light scattering was performed on polyplexes of mRNA encoding firefly luciferase (~2000 bases) or saRNA (~9000 bases) and peptide modified polymers. Polyplex (nanoparticle composition) particle size was around or below 200 nm, similar to what was observed for branched DD90-118 (“bDD90-118” – see Patel et. al., Adv. Mat., 2019, 31, 1805116). Positive zeta potentials were recorded that were slightly lower than that for bDD90- 118 : mRNA (see Patel et. al., Adv. Mat., 2019, 31, 1805116). The results are shown in Table 2, below, and in FIG.8 to 10. Example 7 – Peptide synthesis Peptide synthesis was carried out on an automated peptide synthesizer using standard Fmoc-based solid-phase synthesis protocols. Briefly; 1. Rink Amide AM resin was first swollen in DMF and then transferred to the reaction vessel. Each coupling step employed 3 equivalents of the Fmoc- protected amino acid, 6 equivalents of Oxyma, and 6 equivalents of DIC, and the reaction was allowed to proceed at room temperature for 90 minutes. 2. After coupling, the resin was washed sequentially with DMF and DCM. Fmoc deprotection was performed using 20% piperidine in DMF. 3. Upon completion of the synthesis, the peptide was cleaved from the resin using a cleavage cocktail consisting of TFA / water / TIS (19:1:1, v / v / v). 4. The crude peptide was precipitated and washed with cold anhydrous ether. Final purification was achieved using a C18 reversed-phase flash chromatography column. Example 8 – Synthesis of peptide modified polymers 1. PBAE-Nb (DD-90 backbone) was prepared a) Backbone monomers bisphenol A glycerolate (DD) and 4-(2- aminoethyl)morpholine (90) were dissolved in anhydrous dimethylformamide at 150 mg / mL in separate vials. b) 10 mL of DD was mixed with 2.56 mL of 90, (equivalent to molar ratio of 1.05 to 1). c) The mixture was reacted at 90°C for 48 hours. d) 1 mL 5-Norbornene-2-methylamine (TCI, N0907) was added and reacted for another 24 h. e) PBAE-Nb was precipitated by cold diethyl ether (1:10), re-dissolved in THF and precipitation repeated in cold diethyl ether. Vacuum dried overnight and characterised by proton NMR (FIG.11). 2. PBAE-peptide was prepared in dimethyl sulfoxide (DMSO). a. 0.1 % solution of photoinitiator (Irgacure2959, Sigma, 410896) was prepared in DMSO. b. PBAE-Nb was dissolved in photoinitiator solution at 100 mg / mL. c. A peptide (Table 1) was added at 1.2 eq to Nb in photoinitiator solution. A typical concentration was 10-30 mg / mL, this depended on the molecular weight of peptide and PBAE-Nb. d. 1:1 v / v eg 50 uL PBAE-Nb solution was mixed with 50 uL peptide solution in a polypropylene tube and exposed to UV at 200 mW / cm2 for 3 min. e. Store at -80 °C. Example 9 – PBAE-peptide complexation with mRNA in phosphate buffered saline (PBS) for intracellular delivery at 50:1 mass ratio of polymer to mRNA 1. PBAE-peptide + mRNA polyplex was prepared: a. mRNA was diluted in water to a concentration of 6.67 ug / mL b. 1 uL DD90-peptide (50 mg / mL) was diluted in 14 uL DMSO to generate 3.33 mg / mL PBAE-peptide in DMSO. c. 15 uL of diluted PBAE-peptide was added to 135 uL PBS to generate 333 ug / mL solution. d. 50 uL Peptide-peptide in PBS and 50 uL mRNA solution were mixed and incubated at room temperature for 10 min. e. For 96 well plate, a typical dosage was 50 ng mRNA (15 uL polyplex solution was added) to 135 uL of media per well. f. Suspension cells (eg Jurkat cells) and adherent cells (16HBE, and bone marrow- derived mesenchymal stem cells) were assayed 24 hours after transfection (FIG. 12 and 13). Cells were seeded between 15,000 to 5,000 cells per well. Numbered embodiments 1. A peptide modified polymer for nucleic acid delivery comprising: a radical of Formula (A) having the structure: ; a diradical of Formula (B) having the structure: a diradical of Formula (C) having the structure: wherein: each radical of Formula (A) has one point of attachment to a diradical of Formula (B); each diradical of Formula (B) has two points of attachment to separate radicals independently selected from: Formula (A) and Formula (C); each diradical of Formula (C) has two points of attachment, each to a separate diradical of Formula (B); wherein each X is independently selected from: -O-, -S-, and -NRw-; wherein each Y is independently selected from: =O, =S, and -OH; wherein L1is a hydrocarbyl linker comprising 1 to 500 carbon atoms; wherein R1is a peptide radical; wherein each R2is independently selected from: -H, -C1to C20alkyl; -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, and -C2to C20alkynyl; wherein said -C1to C20alkyl; -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, or -C2to C20alkynyl group is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3 to C20 cycloalkyl, -C3 to C20 heterocycloalkyl, -C2 to C20 alkenyl, -C2 to C20 alkynyl, -OH, -OR4, -NH2, -NHR4, -NR42, -C(O)OH, -C(O)OR4, -C(O)NH2, -C(O)NHR4, -C(O)NR42, - O(CO)H, -O(CO)R4, -NH(CO)H, -NH(CO)R4, -NR4(CO)H, -NR4(CO)R4, -SH, -SR4, -SO2H, -SO2R4, -SO3R4, -SO3H, -SiR43, -NO2, -CN, -F, -Cl, -Br, -I, -C6to C14aryl optionally substituted with one or more R5groups, and -C2to C9heteroaryl optionally substituted with one or more R5groups; wherein each R3is independently selected from: -C1 to C20 alkyl, -C1 to C20 haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyloxy, -C1to C20alkylamino, -C6to C14aryl optionally substituted with one or more R6groups, and -C2to C9heteroaryl optionally substituted with one or more R6groups; wherein said -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyloxy, or -C1to C20alkylamino group is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl-C3to C20cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C1to C20alkyloxy, -C1to C20alkylamino, -OH, -OR7, -NH2, -NHR7, - NR72, -C(O)OH, -C(O)OR7, -C(O)NH2, -C(O)NHR7, -C(O)NR72, -O(CO)H, -O(CO)R7, - NH(CO)H, -NH(CO)R7, -NR7(CO)H, -NR7(CO)R7, -SH, -SR7, -SO2H, -SO2R7, -SO3R7, - SO3H, -SiR73, -NO2, -CN, -F, -Cl, -Br, -I, -C6to C14aryl optionally substituted with one or more R8groups, and -C2to C9heteroaryl optionally substituted with one or more R8groups; wherein each R4is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl- C3to C10cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C1to C20alkoxy, -C1to C20alkylamino, -C6to C14aryl, and -C2to C9heteroaryl; wherein each R5is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I; wherein each R6is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I; wherein each R7is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20 alkynyl, -C1 to C20 alkyl-C6 to C14 aryl, -C1 to C20 alkyl-C2 to C9 heteroaryl, -C1 to C20 alkyl- C3to C10cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C1to C20alkoxy, -C1to C20alkylamino, -C6to C14aryl, and -C2to C9heteroaryl; wherein each R8is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I; and wherein each Rwis independently selected from: -C1 to C20 alkyl, -C1 to C20 haloalkyl, -C3to C20cycloalkyl, and -C2to C20alkenyl. 2. The peptide modified polymer for nucleic acid delivery according to Clause 1 additionally comprising: a radical species of Formula (D) having the structure: wherein: each radical species of Formula (D) has at least two points of attachment to separate diradicals of Formula (B) and each * independently denotes a point of attachment to (i) a separate diradical of Formula (B), or (ii) a substituent R9; wherein L2is a hydrocarbyl linker comprising 1 to 500 carbon atoms; wherein each R9is independently selected from: -H, -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, and -C2to C20alkynyl, wherein said -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, or -C2to C20alkynyl is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, - OR10, -NH2, -NHR10, -NR102, -C(O)OR10, -C(O)NH2, -C(O)NHR10, -C(O)NR102, -O(CO)H, - O(CO)R10, -NH(CO)H, -NH(CO)R10, -NR10(CO)H, -NR10(CO)R10, -SR10, -NO2, -CN, -F, - Cl, -Br, -I, -C6 to C14 aryl optionally substituted with one or more R11groups, and -C2 to C9 heteroaryl optionally substituted with one or more R11groups; wherein each R10is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl- C3to C10cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C1to C20alkoxy, -C1to C20alkylamino, -C6to C14aryl, and -C2to C9heteroaryl; and wherein each R11is independently selected from: -C1 to C20 alkyl, -C1 to C20 haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I. 3. The peptide modified polymer according to Clause 1 or Clause 2, wherein the diradical of Formula (B) is defined by Formula (B-I): wherein each R2and L1are as defined by any of the preceding clauses. 4. The peptide modified polymer according to any one of Clauses 1 to 3, wherein L1is selected from: divalent -C2to C8hydrocarbyl and wherein each R12is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, - OC1to C20alkyl, -NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I; wherein each R13is independently selected from: -H, -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, and - C2to C20alkynyl; and wherein each Z is independently selected from an integer from 0 to 4; preferably wherein: i) L1is ; wherein n is an integer selected from 0 to 250, wherein each R2is -H. 5. The peptide modified polymer according to any one of Clauses 1 to 4, wherein R3is 6. The peptide modified polymer according to any one of Clauses 2 to 5, wherein the radical species of Formula (D) is defined by Formula (D-I): wherein R9and L2are as defined by any of the preceding clauses. 7. The peptide modified polymer according to any one of Clauses 2 to 6, wherein: each R9is independently selected from: -H, -C1to C8alkyl, -C1to C8haloalkyl, -C3to C8cycloalkyl, -C3to C8heterocycloalkyl, -C2to C8alkenyl, and -C2to C8alkynyl; and / or wherein L2is divalent -C2to C8alkylene, for example . 8. The peptide modified polymer according to any one of Clauses 1 to 7, wherein each R1is a peptide radical defined by the structure: ; wherein each RXis a dipeptide or tripeptide radical; wherein each RYis a peptide diradical or is absent. 9. The peptide modified polymer according to any one of Clauses 1 to 8, wherein each RXand each RYcomprise one or more amino acids selected from: Ala, Cys, Arg, Asp, Ser, Glu, Gln, Lys, Gly, His, and Sar; or wherein RYis absent. 10. The peptide modified polymer according to any one of Clauses 1 to 9, wherein RYcomprises or consists of a peptide diradical selected from:

[0020] and wherein * denotes the point of attachment to the radical of RX; and / or wherein each RXradical is selected from: ,

[0021] . 11. The peptide modified polymer according to any one of Clauses 1 to 10, wherein each RXradical is selected from: ,

[0022] . 12. The peptide modified polymer according to any one of Clauses 1 to 11, wherein the peptide modified polymer has a molecular weight (MW) of 1 kDa to 100 kDa, preferably 5 kDa to 50 kDa, more preferably 10 kDa to 40 kDa. 13. A nanoparticle composition comprising the peptide modified polymer according to any one of Clauses 1 to 12, and a polynucleotide; preferably wherein the z-average mean diameter of the nanoparticles is from 10 to 500 nm, preferably from 100 to 250 nm, as measured by dynamic light scattering. 14. A composition comprising a peptide modified polymer according to any one of Clauses 1 to 12 in addition to a polynucleotide, or a nanoparticle composition according to Clause 12 ; and a pharmaceutically acceptable excipient. 15. The composition according to Clause 14, wherein the polynucleotide is DNA. 16. The composition according to Clause 14, wherein the polynucleotide is RNA, for example, mRNA, ssRNA, circRNA, dsRNA, saRNA, siRNA, shRNA, or miRNA, preferably wherein the RNA is mRNA. 17. The composition according to any one of Clauses 14 to 16, wherein the composition is packaged in a non-viral delivery system, preferably wherein the non- viral delivery system is selected from: (i) a nanoparticle, for example a lipid nanoparticle, a polypeptide nanoparticle, a silica nanoparticle, a gold nanoparticle, a polymeric nanoparticle; (ii) a microparticle; or (iii) a micelle, a lipoplex, a liposome, a dendrimer, a cationic nano emulsion, an inorganic carrier (such as CaP), a polymer and a lipid hybrid carrier. 18. The composition according to any one of Clauses 14 to 17, wherein the composition is formulated for nebulisation, aerosol delivery, or intranasal delivery. 19. A nasal spray comprising the composition of any one of Clauses 14 to 18. 20. An in vitro method of delivering polynucleotides to cells, the method comprising contacting the composition according to any one of Clauses 14 to 18, or the nasal spray according to Clause 19, with said cells. 21. A composition according to any one of Clauses 14 to 18, or a nasal spray according to Clause 19, for use in treating a disease or disorder, preferably a lung disease or disorder, for example wherein the lung disease or disorder is selected from: (i) chronic obstructive pulmonary disease, emphysema, asthma, chronic obstructive pulmonary disease (COPD), chronic bronchitis, emphysema, and pulmonary hypertension, sarcoidosis, influenza, pneumonia, tuberculosis; (ii) pulmonary fibrosis, for example idiopathic pulmonary fibrosis, fibrotic interstitial lung disease, interstitial pneumonia, fibrotic variant of non- specific interstitial pneumonia, cystic fibrosis; and / or (iii) lung cancer and lung cancer asthma. 22. A method for preparing a peptide modified polymer according to any one of Clauses 1 to 12, the method comprising the steps of: (i) contacting an amine having the structure of Formula (I): H2N-R3, e structure of Formula (II): in an organic solvent; (ii) agitating and optionally heating the solution of step (i); (ii) contacting the reaction mixture with a peptide of Formula (VI): R1-H; and (iv) agitating the reaction mixture; to thereby prepare the peptide modified polymer; wherein each R1, R2, R9, L1, L2, X, and Y are as defined by any of the preceding clauses. 23. The method according to Clause 22, the method comprising the steps of: (i) contacting an amine having the structure of Formula (I): H2N-R3, with an alkene having the structure of Formula (II): an amine selected from: Formula (III): , Formula (IV): Formula (V): ; in an organic solvent; (ii) agitating and optionally heating the solution of step (i); (iii) contacting the reaction mixture with a peptide of Formula (VI): R1-H; and (iv) agitating the reaction mixture; to thereby prepare the peptide modified polymer; wherein each R1, R2, R9, L1, L2, X, and Y are as defined by any of the preceding clauses. 24. The method according to Clause 22 or Clause 23, wherein: a. the organic solvent is selected from: DMSO, DMF, and THF; b. the reaction mixture of step (i) is heated at about 20 °C to about 190 °C, preferably about 80 °C to about 100 °C, for example about 90 °C; and / or c. the reaction mixture of step (iv) is heated at about 20 °C to about 60 °C, preferably about 25 °C to about 40 °C, for example about 30 °C; and / or d. the ratio of the alkene of Formula (II) to the amine of Formula (I) is about 1.5 to about 1.0, preferably from about 1.2 to about 1.0 or from about 1.05 to about 1.0. 25. A method for preparing a nanoparticle composition according to Clause 13, the method comprising the steps of: (i) providing the peptide modified polymer according to any one of Clauses 1 to 12 in an organic solvent; (ii) combining the organic solvent with an aqueous buffer; (iii) suspending a polynucleotide in water or an aqueous buffer, for example a sodium citrate buffer or phosphate-buffered saline (PBS); (iv) combining the mixture produced by step (ii) with the mixture produced by step (iii); to thereby prepare the nanoparticle composition.

Claims

1. CLAIMS 1. A peptide modified polymer for nucleic acid delivery comprising: a radical of Formula (A) having the structure: ; a diradical of Formula (B) having the structure: wherein: each radical of Formula (A) has one point of attachment to a diradical of Formula (B); each diradical of Formula (B) has two points of attachment to separate radicals independently selected from: Formula (A) and Formula (C); each diradical of Formula (C) has two points of attachment, each to a separate diradical of Formula (B); wherein each X is independently selected from: -O-, -S-, and -NRw-; wherein each Y is independently selected from: =O, =S, and -OH; wherein L1is a hydrocarbyl linker comprising 1 to 500 carbon atoms; wherein R1comprises a peptide radical; wherein each R2is independently selected from: -H, -C1to C20alkyl; -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, and -C2to C20alkynyl; wherein said -C1to C20alkyl; -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, or -C2to C20alkynyl group is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -OR4, -NH2, -NHR4, -NR42, -C(O)OH, -C(O)OR4, -C(O)NH2, -C(O)NHR4, -C(O)NR42, - O(CO)H, -O(CO)R4, -NH(CO)H, -NH(CO)R4, -NR4(CO)H, -NR4(CO)R4, -SH, -SR4, -SO2H, -SO2R4, -SO3R4, -SO3H, -SiR43, -NO2, -CN, -F, -Cl, -Br, -I, -C6to C14aryl optionally substituted with one or more R5groups, and -C2 to C9 heteroaryl optionally substituted with one or more R5groups; wherein each R3is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyloxy, -C1to C20alkylamino, -C6to C14aryl optionally substituted with one or more R6groups, and -C2to C9heteroaryl optionally substituted with one or more R6groups; wherein said -C1 to C20 alkyl, -C1 to C20 haloalkyl, -C3 to C20 cycloalkyl, -C3 to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyloxy, or -C1to C20alkylamino group is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl-C3to C20cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C1to C20alkyloxy, -C1to C20alkylamino, -OH, -OR7, -NH2, -NHR7, - NR72, -C(O)OH, -C(O)OR7, -C(O)NH2, -C(O)NHR7, -C(O)NR72, -O(CO)H, -O(CO)R7, - NH(CO)H, -NH(CO)R7, -NR7(CO)H, -NR7(CO)R7, -SH, -SR7, -SO2H, -SO2R7, -SO3R7, - SO3H, -SiR73, -NO2, -CN, -F, -Cl, -Br, -I, -C6to C14aryl optionally substituted with one or more R8groups, and -C2to C9heteroaryl optionally substituted with one or more R8groups; wherein each R4is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl- C3to C10cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C1to C20alkoxy, -C1to C20alkylamino, -C6to C14aryl, and -C2to C9heteroaryl; wherein each R5is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I; wherein each R6is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I; wherein each R7is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl- C3to C10cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C1to C20alkoxy, -C1to C20alkylamino, -C6to C14aryl, and -C2to C9heteroaryl; wherein each R8is independently selected from: -C1 to C20 alkyl, -C1 to C20 haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I; and wherein each Rwis independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, and -C2to C20alkenyl.

2. The peptide modified polymer for nucleic acid delivery according to Claim 1, wherein R1is a peptide radical.

3. The peptide modified polymer for nucleic acid delivery according to Claim 1 or Claim 2 additionally comprising: a radical species of Formula (D) having the structure: wherein: each radical species of Formula (D) has at least two points of attachment to separate diradicals of Formula (B) and each * independently denotes a point of attachment to (i) a separate diradical of Formula (B), or (ii) a substituent R9; wherein L2is a hydrocarbyl linker comprising 1 to 500 carbon atoms; wherein each R9is independently selected from: -H, -C1 to C20 alkyl, -C1 to C20 haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, and -C2to C20alkynyl, wherein said -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, or -C2to C20alkynyl is optionally substituted with one or more group independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, - OR10, -NH2, -NHR10, -NR102, -C(O)OR10, -C(O)NH2, -C(O)NHR10, -C(O)NR102, -O(CO)H, - O(CO)R10, -NH(CO)H, -NH(CO)R10, -NR10(CO)H, -NR10(CO)R10, -SR10, -NO2, -CN, -F, - Cl, -Br, -I, -C6to C14aryl optionally substituted with one or more R11groups, and -C2to C9heteroaryl optionally substituted with one or more R11groups; wherein each R10is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -C1to C20alkyl-C6to C14aryl, -C1to C20alkyl-C2to C9heteroaryl, -C1to C20alkyl- C3to C10cycloalkyl, -C1to C20alkyl-C3to C10heterocycloalkyl, -C1to C20alkoxy, -C1to C20alkylamino, -C6to C14aryl, and -C2to C9heteroaryl; and wherein each R11is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, -OC1to C20alkyl, -NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I.

4. The peptide modified polymer according to any one of Claims 1 to 3, wherein the diradical of Formula (B) is defined by Formula (B-I):wherein each R2and L1are as defined by any of the preceding claims.

5. The peptide modified polymer according to any one of Claims 1 to 4, wherein L1is selected from: divalent -C2to C8hydrocarbyl andwherein each R12is independently selected from: -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C2to C20alkenyl, -C2to C20alkynyl, -OH, -NH2, - OC1to C20alkyl, -NHC1to C20alkyl, -N(C1to C20alkyl)2, -NO2, -CN, -F, -Cl, -Br, and -I; wherein each R13is independently selected from: -H, -C1to C20alkyl, -C1to C20haloalkyl, -C3to C20cycloalkyl, -C3to C20heterocycloalkyl, -C2to C20alkenyl, and - C2to C20alkynyl; and wherein each Z is independently selected from an integer from 0 to 4; preferably wherein: i) L1is ; wherein n is an integer selected from 0 to 250, for example n is 0 or 2; or ii) wherein L1is selected from:,wherein each R2is -H.

6. The peptide modified polymer according to any one of Claims 1 to 5, wherein R3is7. The peptide modified polymer according to any one of Claims 3 to 6, wherein the radical species of Formula (D) is defined by Formula (D-I):wherein R9and L2are as defined by any of the preceding claims.

8. The peptide modified polymer according to any one of Claims 3 to 7, wherein: each R9is independently selected from: -H, -C1to C8alkyl, -C1to C8haloalkyl, -C3to C8cycloalkyl, -C3to C8heterocycloalkyl, -C2to C8alkenyl, and -C2to C8alkynyl; and / or wherein L2is divalent -C2to C8alkylene, for example.

9. The peptide modified polymer according to any one of Claims 1 to 8, wherein each R1is a peptide radical defined by the structure: ; wherein each RXis a dipeptide or tripeptide radical; wherein each RYis a peptide diradical or is absent.

10. The peptide modified polymer according to any one of Claims 1 to 9, wherein each RXand each RYcomprise one or more amino acids selected from: Ala (A), Cys (C), Arg (R), Asp (D), Ser (S), Glu (E), Gln (Q), Lys (K), Gly (G), His (H), and Sar; or wherein RYis absent.

11. The peptide modified polymer according to any one of Claims 1 to 10, wherein RYcomprises or consists of a peptide diradical selected from:and wherein * denotes the point of attachment to the radical of RX; and / or wherein each RXradical is selected from:,.

12. The peptide modified polymer according to any one of Claims 1 to 11, wherein each RXradical is selected from:.

13. The peptide modified polymer according to any one of Claims 1 to 8, wherein each R1is a radical defined by the structure: ;wherein each RXis a dipeptide or tripeptide radical; wherein each RYis a peptide diradical or is absent; and wherein each L3is a hydrocarbyl linker comprising 1 to 100 carbon atoms, for example 1 to 20 carbon atoms, such as 1 to 10 carbon atoms.

14. The peptide modified polymer according to claim 13, wherein L3is a diradical definedwherein denotes the point of attachment to the radical of RY(if RYis present) or RX(if RYis absent).

15. The peptide modified polymer according to Claim 13 or Claim 14, wherein each RXand each RYcomprise one or more amino acids selected from: Ala (A), Cys (C), Arg (R), Asp (D), Ser (S), Glu (E), Gln (Q), Lys (K), Gly (G), His (H), and Sar, for example wherein each RXand / or each RYcomprise one or more Cys (C); or wherein RYis absent.

16. The peptide modified polymer according to any one of Claims 13 to 15, wherein each is selected from: DGRCG-NH2(RGD), DGRGGCG-NH2(G2RGD), DGRGGGGCG-NH2 (G4RGD), DGRGGGGGGCG-NH2 (G6RGD), DGRGGGGGGGGCG-NH2(G8RGD), DGRAACG-NH2(A2RGD), DGRAAAACG-NH2(A4RGD), DGRAAAAAACG-NH2(A6RGD), DGRAAAAAAAACG-NH2(A8RGD), DGRKECG-NH2 (EK2RGD), DGRKEKECG-NH2 (EK4RGD), DGRKEKEKECG-NH2 (EK6RGD), DGRKEKEKEKECG-NH2(EK8RGD), GDRCG-NH2(RDG), EGRCG-NH2(RGE), GDRKECG-NH2(EKRDG), and EGRKECG-NH2(EKRGE).

17. The peptide modified polymer according to any one of Claims 13 to 16, wherein the point of attachment of RYto L3is via a Cys (C) sulfur atom.

18. The peptide modified polymer according to any one of Claims 1 to 17, wherein the peptide modified polymer has a molecular weight (MW) of 1 kDa to 100 kDa, preferably 5 kDa to 50 kDa, more preferably 10 kDa to 40 kDa.

19. A nanoparticle composition comprising the peptide modified polymer according to any one of Claims 1 to 18, and a polynucleotide; preferably wherein the z-average mean diameter of the nanoparticles is from 10 to 500 nm, preferably from 100 to 250 nm, as measured by dynamic light scattering.

20. A composition comprising a peptide modified polymer according to any one of Claims 1 to 18 in addition to a polynucleotide, or a nanoparticle composition according to Claim 18; and a pharmaceutically acceptable excipient.

21. The composition according to Claim 20, wherein the polynucleotide is DNA.

22. The composition according to Claim 20, wherein the polynucleotide is RNA, for example, mRNA, ssRNA, circRNA, dsRNA, saRNA, siRNA, shRNA, or miRNA, preferably wherein the RNA is mRNA.

23. The composition according to any one of Claims 20 to 22, wherein the composition is packaged in a non-viral delivery system, preferably wherein the non-viral delivery system is selected from: (i) a nanoparticle, for example a lipid nanoparticle, a polypeptide nanoparticle, a silica nanoparticle, a gold nanoparticle, a polymeric nanoparticle; (ii) a microparticle; or (iii) a micelle, a lipoplex, a liposome, a dendrimer, a cationic nano emulsion, an inorganic carrier (such as CaP), a polymer and a lipid hybrid carrier.

24. The composition according to any one of Claims 20 to 23, wherein the composition is formulated for nebulisation, aerosol delivery, or intranasal delivery.

25. A nasal spray comprising the composition of any one of Claims 20 to 24.

26. An in vitro method of delivering polynucleotides to cells, the method comprising contacting the composition according to any one of Claims 20 to 24, or the nasal spray according to Claim 25, with said cells.

27. A composition according to any one of Claims 20 to 24, or a nasal spray according to Claim 25, for use in treating a disease or disorder, preferably a lung disease or disorder, for example wherein the lung disease or disorder is selected from: (i) chronic obstructive pulmonary disease, emphysema, asthma, chronic obstructive pulmonary disease (COPD), chronic bronchitis, emphysema, and pulmonary hypertension, sarcoidosis, influenza, pneumonia, tuberculosis; (ii) pulmonary fibrosis, for example idiopathic pulmonary fibrosis, fibrotic interstitial lung disease, interstitial pneumonia, fibrotic variant of non- specific interstitial pneumonia, cystic fibrosis; and / or (iii) lung cancer and lung cancer asthma.

28. A method for preparing a peptide modified polymer according to any one of Claims 1 to 11, the method comprising the steps of: (i) contacting an amine having the structure of Formula (I): H2N-R3,with an alkene having the structure of Formula (II):in an organic solvent; (ii) agitating and optionally heating the solution of step (i); (ii) contacting the reaction mixture with a peptide of Formula (VI): R1-H; and (iv) agitating the reaction mixture; to thereby prepare the peptide modified polymer; wherein each R1, R2, R9, L1, L2, X, and Y are as defined by any of the preceding claims.

29. The method according to claim 28, the method comprising the steps of: (i) contacting an amine having the structure of Formula (I): H2N-R3, with an alkene having the structure of Formula (II):an amine selected from: Formula (III):, Formula (IV):Formula (V): ; in an organic solvent; (ii) agitating and optionally heating the solution of step (i); (iii) contacting the reaction mixture with a peptide of Formula (VI): R1-H; and (iv) agitating the reaction mixture; to thereby prepare the peptide modified polymer; wherein each R1, R2, R9, L1, L2, X, and Y are as defined by any of the preceding claims.

30. The method according to Claim 28 or Claim 29, wherein: a. the organic solvent is selected from: DMSO, DMF, and THF; b. the reaction mixture of step (i) is heated at about 20 °C to about 190 °C, preferably about 80 °C to about 100 °C, for example about 90 °C; and / or c. the reaction mixture of step (iv) is heated at about 20 °C to about 60 °C, preferably about 25 °C to about 40 °C, for example about 30 °C; and / ord. the ratio of the alkene of Formula (II) to the amine of Formula (I) is about 1.5 to about 1.0, preferably from about 1.2 to about 1.0 or from about 1.05 to about 1.

0.

31. A method for preparing a peptide modified polymer according to any one of Claims 13 to 17, the method comprising the steps of: (i) contacting an amine having the structure of Formula (I): H2N-R3, with an alkene having the structure of Formula (II):in an organic solvent; (ii) agitating and optionally heating the solution of step (i); (iii) contacting the reaction mixture with 5-norbornene-2-methylamine; (iv) agitating and optionally heating the solution of step (iii); (v) contacting the product of step (iv) with a photoinitiator and a peptide of Formula (VI): R1-H in an organic solvent, wherein R1is a peptide; (vi) agitating and irradiating the solution of step (v); to thereby prepare the peptide modified polymer; wherein each R1, R2, R9, L1, L2, L3, X, and Y are as defined by any of the preceding claims.

32. The method according to Claim 31, wherein: a) R1comprises one or more Cys (C) amino acids; and / or b) the irradiating is with a UV light source.

33. A method for preparing a nanoparticle composition according to Claim 19, the method comprising the steps of: (i) providing the peptide modified polymer according to any one of Claims 1 to 12 in an organic solvent; (ii) combining the organic solvent with an aqueous buffer; (iii) suspending a polynucleotide in water or an aqueous buffer, for example a sodium citrate buffer or phosphate-buffered saline (PBS); (iv) combining the mixture produced by step (ii) with the mixture produced by step (iii); to thereby prepare the nanoparticle composition.

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