Block copolymers comprising a poly(ethylene oxide) with a c1 to c3-alkyloxymethyl side chains block and hydrophobic blocks

Abstract

The present invention refers to novel polyoxyalkylene based block copolymers and their manufacturing method as well as particles comprising at least one novel polyoxyalkylene based block copolymer and at least one active agent. Furthermore, the present invention refers to the manufacture of the particles of the present invention as well as their use for the treatment of an illness in mammals or humans. Moreover, the present invention refers to a medical device comprising at least one block copolymer according to the present invention.

Description

[0001] Block copolymers comprising a poly(ethylene oxide) with a C1 to C3-alkyloxymethyl side chains block and hydrophobic blocks

[0002] Technical Field

[0003] The present invention refers to novel polyoxyalkylene based block copolymers and their manufacturing method as well as particles comprising at least one novel polyoxyalkylene based block copolymer and at least one active agent. Furthermore, the present invention refers to the manufacture of the particles of the present invention as well as their use for the treatment of an illness in mammals or humans. Moreover, the present invention refers to a medical device comprising at least one block copolymer according to the present invention.

[0004] Background

[0005] Amphiphilic block copolymers comprising hydrophilic polyethylene oxide) and hydrophobic polymer blocks are important materials in the medical device industry and pharmaceutical technology. Monomers that are typically used for the hydrophobic blocks are inter alia lactides, glycolide and caprolactone. The hydrophilic block is typically poly(ethylene oxide) (PEO). PEO is known for its biocompatibility and the so-called “stealth effect” that avoids recognition by the patient’s reticuloendothelial system. Hydrophilicity of the block copolymers can be tailored by molecular weight of the hydrophilic and hydrophobic blocks and monomers chosen for the hydrophobic segments. The number and order of blocks in the polymer chain is also important for the properties. AB and ABA type block copolymers are typically used. Self-organization of the amphiphilic molecules enables self-organization in aqueous media to nano-scaled polymeric micelles. The assemblies comprise a hydrophobic polyester core and a hydrophilic polyether corona. They are used as carriers for actives and dyes in pharmaceutical technology. Amphiphilic block copolymers are further used in medical device industry because of the improved hydrophilicity of the devices compared to using solely hydrophobic polymers. The improved hydrophilicity leads to faster uptake of water and degradation caused by hydrolysis. Fine control of hydrophilicity enables control over degradation speed and mechanical properties of the device.

[0006] A major concern of PEO is the immune response of the patient’s body that can lead to the formation of anti- PEG antibodies (APA). APAs can cause adverse reactions, i.e. allergic reactions, and the loss of the “stealth effect” resulting in decrease of functionality of the drug. Copolymers of poly(ethylene oxide) and poly(ethylene oxide) having C1 to C3-alkyloxymethyl side chains are a class of polymers that can be tailored to exhibit similar physicochemical characteristics compared to PEO homopolymers.

[0007] Therefore, there is a need for novel amphiphilic block copolymers that do not show the formation of anti- PEO antibodies, i.e. immunogenic potential, which are suitable in the medical device industry and pharmaceutical technology. The inventors of the present invention found that the block copolymers of the present invention can fulfill this need. The randomized poly(ethylene glycol) copolymer (rPEG) structure of the block copolymers of the present invention impedes the interaction with anti-PEG antibodies due to the increased spatial requirements of the alkyloxy methyl side chains. Combination of hydrophilic rPEG blocks with hydrophobic polymer blocks leads to amphiphilic block copolymers. The block copolymers show similar or improved functionality in medical device industry and pharmaceutical technology without the immunogenic potential. Moreover, in the novel block copolymers it is possible to control the number and type (C1 to C3) of alkoxy methyl side chains inside the rPEG blocks. This enables additional control over hydrophilicity and crystallinity of the materials compared to using solely PEG. In particular, the novel block copolymers show miscibility of the two polymer phases and absence of crystallinity. This can lead to desirable characteristics like matrix homogeneity, faster and homogeneous water uptake and hydrolyzation, or absence of phase mixing and phase transitions that can impact storage stability.

[0008] Summary of the invention

[0009] Therefore, in a first aspect the present invention refers to a block copolymer obtained by reacting at least one monomer selected from L-lactide, D-lactide, DL-lactide, epsilon-caprolactone, trimethylene carbonate, delta-valerolactone, alpha-methylene-delta-valerolactone, 3,9-diethyliden-2,4,8, 10- tetraoxaspiro(5.5)undecane, aspartic acid, glutamic acid, glycolide, and para-dioxanone; with a prepolymer H-[A]-R1; wherein [A] is a polyoxyalkylene group comprising at least one unit

[0010] .0.

[0011] (a) L and at least one unit selected from the group of

[0012] R1is selected from -H; -OH; -SH; -NH2; -NHR2, -NR3R4, -OR5, -SR5or linear, branched or cyclic alkyl groups having up to 20 carbon atoms; and wherein

[0013] R2to R5are independently selected from linear, branched or cyclic alkyl groups having up to 20 carbon atoms, in which up to 5 carbon atoms can be substituted with an oxygen or a sulfur atom; in the presence of a catalyst.

[0014] In a second aspect the present invention refers to a method of producing a block copolymer comprising or consisting of the steps: providing a prepolymer H-[A]-R1; wherein [A] is a polyoxyalkylene group comprising at least one unit R1is selected from -H; -OH; -SH; -NH2; -NHR2, -NR3R4, -OR5, -SR5or linear, branched or cyclic alkyl groups having up to 20 carbon atoms; and wherein

[0015] R2to R5are independently selected from linear, branched or cyclic alkyl groups having up to 20 carbon atoms, in which up to 5 carbon atoms can be substituted with an oxygen or a sulfur atom; and allowing the prepolymer to react with at least one monomer selected from L-lactide, D-lactide, DL-lactide, epsilon- caprolactone, trimethylene carbonate, delta-valerolactone, alpha-methylene-delta-valerolactone, 3,9- diethyliden-2,4,8,10-tetraoxaspiro(5.5)undecane, aspartic acid, glutamic acid, glycolide, and para- dioxanone; in the presence of a catalyst.

[0016] In a third aspect the present invention refers to a particle comprising at least one block copolymer according to the present invention or at least one block copolymer obtained by the method according to the present invention.

[0017] In a fourth aspect the present invention pertains to a method of producing a particle according to the present invention comprising or consisting of the steps: i) dissolving at least one block copolymer according to any of claims 1 to 7 or a block copolymer obtained by the method according to claim 8 in an organic solvent in order to obtain a dispersed phase; ii) dissolving at least one stabilizer, such as polyvinyl alcohol (PVA), in water, preferably deionized water, in order to obtain a continuous phase;

[0018] Hi simultaneously pumping the dispersed phase and the continuous phase into a sonicator in order to obtain an emulsion; iv) extracting the emulsion, inline, into a stream of water, preferably deionized water in order to obtain the particles.

[0019] In a fifth aspect the present invention refers to a particle according to the present invention for the treatment of an illness in humans.

[0020] In a sixth aspect the present invention pertains to a particle according to the present invention for the treatment of an illness in mammals.

[0021] In a final aspect the present invention refers to a medical device comprising at least one block copolymer according to the present invention or at least one block copolymer obtained by the method according to the present invention.

[0022] These and other aspects, embodiments, features, and advantages of the invention will become apparent to a person skilled in the art through the study of the following detailed description and claims. Any feature from one aspect of the invention can be used in any other aspect of the invention. Furthermore, it will readily be understood that the examples contained herein are intended to describe and illustrate the invention but not to limit the invention and that, in particular, the invention is not limited to these examples. Detailed description of the invention

[0023] As used herein, the following terms have the meanings ascribed to them unless specified otherwise.

[0024] Unless the context requires otherwise, throughout the present specification and claims, the word "comprise" and variations thereof, such as, "comprises", "comprising", “contain”, and “containing” are to be construed in an open and inclusive sense, that is, as "including, but not limited to".

[0025] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of skill in the art. As used in the specification and claims, the singular form "a", "an" and "the" include plural references unless the context clearly dictates otherwise.

[0026] Numerical ranges that are indicated in the format “from x to y” also include the stated values. If several preferred numerical ranges are indicated in this format, it is self-evident that all ranges that result from the combination of the various endpoints are also included.

[0027] "One or more", as used herein, relates to at least one and comprises 1 , 2, 3, 4, 5, 6, 7, 8, 9 or more of the referenced species. Similarly, "at least one" means one or more, i.e., 1 , 2, 3, 4, 5, 6, 7, 8, 9 or more. "At least one", as used herein in relation to any component, refers to the number of chemically different molecules, i.e. to the number of different types of the referenced species, but not to the total number of molecules. For example, "at least one therapeutic agent" means that at least one type of molecule falling within the definition for a therapeutic agent is used but that also two or more different types of therapeutic agents falling within this definition can be present, but does not mean that only one or more molecules of one type of therapeutic agents are present.

[0028] All percentages given herein in relation to the compositions relate to wt.-% relative to the total weight of the respective composition, if not explicitly stated otherwise.

[0029] “Essentially free of’ according to the present invention with regard to compounds means that the compound can only be present in an amount, which does not influence the characteristics of the composition, in particularthe respective compound is present in less than 3 wt.-%, preferably 1 wt.-%, more preferably 0.01 wt.-%, based on the total weight of the composition or is not present at all.

[0030] The term "nucleic acid(s)" as used herein refers to a compound(s) containing at least two deoxyribonucleotides or ribonucleotides in either single- or double- or triple-stranded form and includes DNA, RNA, and hybrids thereof. DNA may be in the form of antisense molecules, plasmid DNA (pDNA), linear or circular DNA, PCR products, or vectors. RNA may be in the form of self-amplifying RNA (saRNA) or small hairpin RNA (shRNA), small interfering RNA (siRNA), chemically modified or unmodified messenger RNA (mRNA), antisense RNA, circular RNA (circRNA) comprising at least one coding sequence, micro RNA (miRNA), micRNA, multivalent RNA, transfer RNA (tRNA), single guided RNA (sgRNA), replicating RNA (repRNA), dicer substrate RNA or viral RNA (vRNA), antisense oligonucleotide (ASO), double-stranded RNA (dsRNA) and combinations thereof. Nucleic acids include nucleic acids containing known nucleotide analogs or modified backbone residues or linkages, which are synthetic, naturally occurring, and non-naturally occurring, and which have similar binding properties as the reference nucleic acid. Examples of such analogs include, without limitation, phosphorothioates, phosphoramidates, methyl phosphonates, chiral-methyl phosphonates, 2'-O-methyl ribonucleotides, and peptide-nucleic acids (PNAs). Unless specifically limited, the term encompasses nucleic acids containing known analogues of natural nucleotides that have similar binding properties as the reference nucleic acid. Unless otherwise indicated, a particular nucleic acid sequence also implicitly encompasses conservatively modified variants thereof (e.g., degenerate codon substitutions), alleles, orthologs, single nucleotide polymorphisms, and complementary sequences as well as the sequence explicitly indicated.

[0031] An "effective amount" or "therapeutically effective amount" of an active agent such as a nucleic acid is an amount sufficient to produce the desired effect, e.g., an increase or inhibition of expression of a target sequence in comparison to the normal expression level detected in the absence of the nucleic acid. An increase in expression of a target sequence is achieved when any measurable level is detected in the case of an expression product that is not present in the absence of the nucleic acid. In the case where the expression product is present at some level prior to contact with the nucleic acid, an in increase in expression is achieved when the fold increase in value obtained with a nucleic acid such as mRNA relative to control is about 1.05, 1.1 , 1.2, 1.3, 1.4, 1.5, 1.75, 2, 2.5, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 40, 50, 75, 100, 250, 500, 750, 1000, 5000, 10000, or greater. Inhibition of expression of a target gene or target sequence is achieved when the value obtained with a nucleic acid such as antisense oligonucleotide relative to the control is about 95%, 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55%, 50%, 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10%, 5%, or 0%. Suitable assays for measuring expression of a target gene or target sequence include, e.g., examination of protein or RNA levels using techniques known to those of skill in the art such as dot blots, northern blots, in situ hybridization, ELISA, immunoprecipitation, enzyme function, fluorescence, or luminescence of suitable reporter proteins, as well as phenotypic assays known to those of skill in the art.

[0032] A "stereoisomer" refers to a compound made up of the same atoms bonded by the same bonds but having different three-dimensional structures, which are not interchangeable. The present invention contemplates various stereoisomers and mixtures thereof and includes "enantiomers", which refers to two stereoisomers whose molecules are non-superimposable mirror images of one another.

[0033] A "tautomer" refers to a proton shift from one atom of a molecule to another atom of the same molecule. The present disclosure includes tautomers of any said compounds.

[0034] "Pharmaceutically acceptable salt" includes both acid and base addition salts.

[0035] The invention in particular refers to a block copolymer obtained or obtainable by reacting at least one monomer, preferably one or two monomers, selected from L-lactide, D-lactide, DL-lactide, epsilon-caprolactone, trimethylene carbonate, delta-valerolactone, alpha-methylene-delta-valerolactone, 3,9-diethyliden-2,4,8,10-tetraoxaspiro(5.5)undecane, a prepolymer of 3,9-diethyliden-2,4,8,10 tetraoxaspiro(5.5)undecane with a diol; aspartic acid, glutamic acid, glycolide, and para-dioxanone; with a prepolymer H-[A]-R1; wherein [A] is a polyoxyalkylene group comprising at least one unit .0.

[0036] (a) L and at least one unit selected from the group of

[0037] R1is selected from -H; -OH; -SH; -NH2; -NHR2, -NR3R4, -OR5, -SR5or linear, branched or cyclic alkyl groups having up to 20 carbon atoms; and wherein

[0038] R2to R5are independently selected from linear, branched or cyclic alkyl groups having up to 20 carbon atoms, in which up to 5 carbon atoms can be substituted with an oxygen or a sulfur atom; in the presence of a catalyst.

[0039] In one embodiment the block copolymer has a number average molecular weight of 1 ,200 to 600,000 g / mol, preferably 2,000 to 250,000 g / mol, more preferably 2,000 to 100,000 g / mol, still more preferably 5,000 to 100,000 g / mol, still more preferably 25,000 to 100,000 g / mol preferably determined via size exclusion chromatography using a refractive index (Rl) detector and polyethylene oxide standards. The size-exclusion chromatography can preferably be performed with dimethylformamide (DMF with 1 g / L LiBr) as the mobile phase (flow rate 1 mL / min) on poly(2-hydroxyethylmethacrylat) (PHEMA) 300 / 100 / 40 columns at 50 °C. Polymer concentrations were 1 mg / mL. Calibration was carried out using polyethylene oxide standards (from Polymer Standard Service, Mainz, Germany).

[0040] In another embodiment the block copolymer has a number average molecular weight of 1 ,500 to 3,000 g / mol. In one embodiment the dispersity (PDI) of the block copolymer is higher than 1 .5, preferably 1 .5 to 3.0.

[0041] In one embodiment the catalyst is a ring opening catalyst or a polycondensation catalyst, preferably the ring opening catalyst is a tin catalyst, more preferably tin (II) 2-ethylhexanoate, or preferably the polycondensation catalyst is an organic acid, more preferably p-toluenesulfonic acid. In a preferred embodiment the catalyst is not 1 ,8-Diazabicyclo[5.4.0]undec-7-ene.

[0042] Polycondensation reactions and ring opening polymerizations reactions are well known to the skilled person in the field. Suitable polycondensation reaction conditions are for example disclosed in WO 2022 / 152835 A1 and suitable ring opening polymerization conditions are for example disclosed by D.Bendix in Polymer Degradation and Stability, Volume 59, Issues 1-3, 3 January 1998, Pages 129-135.

[0043] In one embodiment the at least one monomer, preferably one or two monomers, is selected from L- lactide, D-lactide, DL-lactide, epsilon-caprolactone, trimethylene carbonate, delta-valerolactone, alpha- methylene-delta-valerolactone, glycolide, and para-dioxanone, preferably from L-lactide, D-lactide, DL- lactide, epsilon-caprolactone, and glycolide, more preferably from L-lactide, D-lactide, DL-lactide, and glycolide.

[0044] In one embodiment, when the at least one monomer is two monomers, one is selected from the group of L-lactide, D-lactide, DL-lactide, in the following referred to as lactide, and the other one is glycolide, the amount of lactide and glycolide can vary. In a further embodiment the amounts are 1 to 99 mole %, 40 to 99 mole %, 50 to 99 mole %, 60 to 99 mole %, 70 to 99 mole %, or 80 to 99 mole % lactide and from 1 to 99 mole %, 1 to 60 mole %, 1 to 50 mole %, 1 to 40 mole %, or 1 to 20 mole % glycolide, wherein the amount of lactide and glycolide is 100 mole %. In a further embodiment the mole ratios of lactide to glycolide is: 95:5 (polylactide-co-glycolide), 85:15 poly(lactide-co-glycolide), 75:25 poly(lactide-co- glycolide), 65:35 poly(lactide-co-glycolide), or 50:50 poly(lactide-co-glycolide).

[0045] In one embodiment, when the at least one monomer is two monomers, one is selected from the group of L-lactide, D-lactide, DL-lactide, in the following referred to as lactide, and the other one is caprolactone, the amount of lactide and caprolactone can vary. In a further embodiment the mole ratios of lactide to caprolactone can be 95:5 poly(lactide-co-caprolactone), 85:15 poly(lactide-co-caprolactone), 75:25 poly(lactide-co-caprolactone), 65:35 poly(lactide-co-caprolactone), 50:50 poly(lactide-co-caprolactone), 40:60 poly(lactide-co-caprolactone), 25:75 poly(lactide-co-caprolactone), 10:90 poly(lactide-co- caprolactone), or 5:95 poly(lactide-co-caprolactone).

[0046] In one embodiment, the at least one monomer is a prepolymer of 3,9-diethyliden-2,4,8, 10 tetraoxaspiro(5.5)undecane with a diol, preferably 1 ,6-hexanediol, 1 ,4-cyclohexanedimethanol, triethylene glycol, or a mono, or dilactide or a mono, or diglycolide ester of triethylene glycol. The prepolymer preferably has a number average molecular weight of 3,000 to 50,000 g / mol, preferably determined via size exclusion chromatography using a refractive index (Rl) detector and polyethylene oxide standards. In one embodiment H-[A]-R1has a number average molecular weight of 200 to 200,000 g / mol, preferably 500 to 100,000 g / mol, more preferably 1 ,000 to 50,000 g / mol, preferably determined via size exclusion chromatography using a refractive index (Rl) detector and polyethylene oxide standards. The sizeexclusion chromatography can preferably be performed with dimethylformamide (DMF with 1 g / L LiBr) as the mobile phase (flow rate 1 mL / min) on poly(2-hydroxyethylmethacrylat) (PHEMA) 300 / 100 / 40 columns at 50 °C. Polymer concentrations were 1 mg / mL. Calibration was carried out using polyethylene oxide standards (from Polymer Standard Service, Mainz, Germany).

[0047] In one embodiment the polyoxyalkylene group [A] comprises or consist of at least one unit

[0048] In one embodiment R1is -OR5, preferably wherein R5is selected from linear, branched or cyclic alkyl groups having up to 20 carbon atoms, in which up to 5 carbon atoms can be substituted with an oxygen atom.

[0049] The prepolymer H-[A]-R1is preferably obtained by an anionic ring opening copolymerisation of ethylene oxide with at least one comonomer selected from

[0050] 2-(methoxymethyl)oxirane (glycidyl methyl ether), 1 ,2-epoxy-3-ethoxypropane, 1 ,2-epoxy-3-n- propoxypropane, 1 ,2-epoxy-3-iso-propoxypropane, preferably the at least one comonomer is 2- (methoxymethyl)oxirane; and an initiator, which is suitable to form -R1as defined above for the bock copolymer, the initiator is preferably 1-methoxy-3-(2-methoxyethoxy)propan-2-ol, in the presence of a base.

[0051] The base is preferably a base having a pka of at least 16, preferably of at least 19, more preferably is potassium tert-butoxide.

[0052] In a preferred embodiment, a small amount of pure ethylene oxide is added after the copolymerization step so that 2 to 5 additional units derived from ethylene oxide are present at one or both ends of A.

[0053] The synthesis of HOCH2CH2-A-R3via anionic ring-opening copolymerization is for example described in PCT / EP2022 / 062896, in the document HOCH2CH2-A-R1is referred to as polymer, which is incorporate by reference. The anionic ring-opening copolymerization is preferably performed at a temperature in the range of -10 to 90 °C, more preferably -10 to 70 °C, most preferably -10 to 60°C.

[0054] The polyoxyalkylene group [A] comprises unit (a) and at least one of units (b) to (e). In one embodiment the polyoxyalkylene group [A] essentially consists or consists of unit (a) and at least one of units (b) to (e). In particular, the polyoxyalkylene group [A] is essentially free of residues, or is free of residues.

[0055] In one preferred embodiment the polyoxyalkylene group [A] comprises or consists of units (a) and (b) and optionally a further unit selected from (c) to (e). In one preferred embodiment the polyoxyalkylene group [A] comprises or consists of units (a) and (b).

[0056] For the sake of clarity, the passage comprises unit (a) does not mean that only one unit (a) is present, but that at least one unit of (a) are present in the group, i.e., several monomeric units derived from ethylene oxide can be present. For example, 1 to 20 units (a) can be present in group [A]. The same applies to the passage at least one unit (b) to (e). However, it can be that only one (number) unit (a) or only one (number) unit (b) to (e) is present in group [A], if not explicitly defined otherwise.

[0057] In a preferred embodiment unit (a) makes up 5 to 95% of group [A], whereas the other units add up to 100%. In a further preferred embodiment unit (b) is present in up to 70% of group [A], more preferably unit (b) is present in 30 to 70% of group [A], most preferably unit (a) is additionally present in 30 to 70%, adding up to 100%.

[0058] In a preferred embodiment the molar ratio of (a) to (b) to (e), preferably (a) to (b), is 1 to 9 to 9 to 1 , preferably 2 to 8 to 8 to 2, more preferably 3 to 7 to 7 to 3.

[0059] In a preferred embodiment the dispersity (PDI) of -[A]-R1is 1.15 or less, more preferably 1.10 or less, most preferably 1 .08 or less, wherein preferably the weight average and the number average molecular weight are determined with size-exclusion chromatography as described for Mw above. The size-exclusion chromatography can preferably be performed with dimethylformamide (DMF with 1 g / L LiBr) as the mobile phase (flow rate 1 mL / min) on poly(2-hydroxyethylmethacrylat) (PHEMA) 300 / 100 / 40 columns at 50 °C. Polymer concentrations were 1 mg / mL. Calibration was carried out using polyethylene oxide standards (from Polymer Standard Service, Mainz, Germany).

[0060] The group R1can be modified by choosing a suitable initiator and / or by chemically modifying the end group initially formed during the anionic ring opening copolymerisation in the production of the prepolymer H-[A]- R1. Such reactions are well known in the art. R1can for example be a functional group selected from acetal (dialkoxy), aldehyde (formyl), amide (carboxamido), azide, carbonate (alkoxycarbonyl)oxy), carboxyl (carboxy), carboxylic anhydride, ester (alkoxycarbonyl), ether, halo, haloformyl (carbonohaloridoyl), hemiacetal (alkoxyol), hemiketal (alkoxyol), hydroxy, imide (imido), imine (imino), ketal (dialkoxy), ketone (oyl), orthoester (trialkoxy), primary, secondary, tertiary amino group, primary, secondary and tertiary alkoxy group, sulfhydryl (sulfanyl, H-S-), thioether and combinations thereof. In a preferred embodiment the end group is selected from the group consisting of alkyl, hydrogen, hydroxy, alkoxy, sulfanyl, phthalimide, amide, amine and combinations thereof. The end group can be a primary alkoxy group selected of the formulae R-(CH2)n-O-, wherein R is linear, branched or cyclic alkyl or phenyl and n equals 1 to 20.

[0061] In a preferred embodiment R1is -OR5, wherein R5is selected from linear, branched or cyclic alkyl groups having up to 20 carbon atoms, in which up to 5 carbon atoms can be substituted with an oxygen atom; more preferably R1is selected from methoxy, ethoxy, propoxy, butoxy, pentoxy, hexoxy, heptoxy, octoxy, nonoxy, decanoxy, 2-ethylhexoxy, dodecan-1-oxy, 1-methoxy-3-(2-methoxyethoxy)propan-2-oxy, 1- octadecanoxy, 3-methylbutan-1-oxy, phenylmethanoxy, 3-ethyl-butoxy, and 2,3-dialkoxypropoxy, 1- methoxy-3-(2-methoxyethoxy)propoxy. The end group can be introduced by a suitable initiator, which can be alkyl anions and hydride anions, like metal alkyl or metal hydride compounds of the above-mentioned end groups -R1. Preferably however the alkoxy anion and the thioalkoxy anion are not tertiary alkoxy anions. The imide anion is preferably a phthalimide anion. The metal counterion is preferably Na+, K+or Cs+.

[0062] In one embodiment the initiator is a salt of MeOCH2CH2O_, MeO(CH2CH2O)2_, BenzylOCH2CH2O_, BZO(CH2CH2O)2-, (BZ)2N-CH2CH2O-, (BZ)2N-(CH2CH2O)2-, phthalimide-CH2CH2O-, phthalimide- (CH2CH2O)2_, wherein Me is methyl and Bz is benzyl. Most preferred are MeO(CH2CH2O)2_, BZOCH2CH2O and (Bz)2N-CH2CH2O .The counter ion is preferably Na+, K+or Cs+.

[0063] The initiator may be provided in an inert solvent. The solvent is preferably a non-protic solvent and most preferably dimethyl sulfoxide (DMSO) or toluene. Furthermore, the copolymerization reaction is preferably performed in the same solvent.

[0064] The end-group fidelity of the group -A-R1of the present invention may be determined on the respective prepolymer H-[A]-R1by MALDI TOF or by a combination of MALDI TOF with1H NMR by known methods. The group -[A]-R1of the present invention has preferably an end-group fidelity of at least 95 %, more preferably of at least 98 %.

[0065] The polyoxyalkylene group [A] of the present invention may be a random copolymer. Such groups provide the lowest immunogenicity, as they do not provide a blueprint for the immune system for antibodies. They are intrinsically resistant to an immune response and are therefore preferred embodiments of the present invention.

[0066] In an alternative embodiment the polyoxyalkylene group [A] of the present invention may have a block like structure or a tapered or gradient structure. The methods to prepare such polymers are known to the skilled person in the field of polyoxyalkylenes. In such embodiments it is preferred that no more than 5% of group [A] comprise blocks with more than 15 ethylene oxide derived repeating units, more preferably that no more than 5% of the macromolecules of the polymers comprise blocks with more than 8 ethylene oxide derived repeating units.

[0067] Often crystallizations produce a solvate of a compound of the present invention. As used herein, the term "solvate" refers to an aggregate that comprises one or more molecules of a compound of the invention with one or more molecules of solvent. The solvent may be water, in which case the solvate may be a hydrate. Alternatively, the solvent may be an organic solvent. Thus, the compounds of the present invention may exist as a hydrate, including a monohydrate, dihydrate, hemihydrate, sesquihydrate, trihydrate, tetrahydrate and the like, as well as the corresponding solvated forms. Solvates of compound of the invention may be true solvates, while in other cases the compound of the invention may merely retain adventitious water or be a mixture of water plus some adventitious solvent.

[0068] Furthermore, the present invention refers to a method of producing a block copolymer, preferably according to the present invention, comprising or consisting of the steps: providing a prepolymer H-[A]-R1; wherein [A] is a polyoxyalkylene group comprising at least one unit and at least one unit selected from the group of erein

[0069] R1is selected from -H; -OH; -SH; -NH2; -NHR2, -NR3R4, -OR5, -SR5or linear, branched or cyclic alkyl groups having up to 20 carbon atoms; and wherein

[0070] R2to R5are independently selected from linear, branched or cyclic alkyl groups having up to 20 carbon atoms, in which up to 5 carbon atoms can be substituted with an oxygen or a sulfur atom; and allowing the prepolymer to react with at least one monomer, preferably one or two monomers, selected from L- lactide, D-lactide, DL-lactide, epsilon-caprolactone, trimethylene carbonate, delta-valerolactone, alpha- methylene-delta-valerolactone, 3,9-diethy liden-2,4,8, 10-tetraoxaspiro(5.5)undecane, aspartic acid, glutamic acid, glycolide, and para-dioxanone; in the presence of a catalyst. All above-described embodiments for the block copolymer apply as well for the method.

[0071] Furthermore, the present invention refers to a particle, preferably a nanoparticle, comprising at least one block copolymer according to the present invention or at least one block copolymer obtained by the method according to the present invention.

[0072] In general, any method of preparing particles is suitable and the skilled person knows how to obtain particles according to the present invention. In one embodiment the particles are obtained via a nanosonication process, a preferred process is for example disclosed in WO 2021 / 063813 A1 .

[0073] In one embodiment the nanoparticle according to the present invention further comprising at least one active agent and optionally at least one additive. The at least one active agent is preferably comprised in an effective amount.

[0074] A wide variety of active agents can be used with the particles described herein. In one embodiment, the active agent can be a releasable active agent, i.e., a active agent that can be released from the particle into adjacent tissues or fluids of a subject. In certain embodiments, the active agent can be in or on the particle.

[0075] Various forms of the active agent can be used, which are capable of being released from the particle into adjacent tissues or fluids. To that end, a liquid or solid active agent can be incorporated into the particles described herein. The active agents are at least very slightly water soluble, and preferably moderately water soluble. The active agents can include salts of the active ingredient. As such, the active agents can be acidic, basic, or amphoteric salts. They can be nonionic molecules, polar molecules, or molecular complexes capable of hydrogen bonding. The active agent can be included in the compositions in the form of, for example, an uncharged molecule, a molecular complex, a salt, an ether, an ester, an amide, polymer drug conjugate, or other form to provide the effective biological or physiological activity.

[0076] Active agents, as used herein, include any molecule or compound capable of exerting a desired effect on a cell, tissue, organ, or subject. Such effects may be biological, physiological, or cosmetic. Active agents may be any type of molecule or compound, including e.g., nucleic acids, nucleic acid analogues, peptides and polypeptides, including, e.g., antibodies, such as, e.g., polyclonal antibodies, monoclonal antibodies, antibody fragments; humanized antibodies, recombinant antibodies, recombinant human antibodies, and Primatized™ antibodies, cytokines, growth factors, apoptotic factors, differentiation-inducing factors, cell surface receptors and their ligands; hormones; and small molecules, including small organic molecules or compounds.

[0077] Examples of active agents that incorporated into particles herein include, but are not limited to, peptides, proteins such as hormones, enzymes, antibodies, antibody fragments and the like, nucleic acids such as aptamers, iRNA, mRNA, DNA, RNA, antisense nucleic acid or the like, antisense nucleic acid analogs or the like, low-molecular weight compounds, or high- molecular-weight compounds. Active agents contemplated for use in the disclosed microparticles include anabolic agents, antacids, anti-asthmatic agents, anti-cholesterolemic and anti-lipid agents, anti-coagulants, anti-convulsants, anti-diarrheals, antiemetics, anti- infective agents including antibacterial and antimicrobial agents, anti-inflammatory agents, anti-manic agents, antimetabolite agents, anti-nauseants, anti-neoplastic agents, anti-obesity agents, anti-pyretic and analgesic agents, anti-spasmodic agents, anti-thrombotic agents, antitussive agents, anti- uricemic agents, anti-vascular growth agents, anti-vascular endothelial growth agents, anti-anginal agents, antihistamines, appetite suppressants, biologicals, cerebral dilators, coronary dilators, bronchiodilators, cytotoxic agents, decongestants, diuretics, diagnostic agents, erythropoietic agents, expectorants, gastrointestinal sedatives, hyperglycemic agents, hypnotics, hypoglycemic agents, immunomodulating agents, ion exchange resins, laxatives, mineral supplements, mucolytic agents, neuromuscular drugs, peripheral vasodilators, psychotropics, sedatives, stimulants, thyroid and antithyroid agents, tissue growth agents, vascular growth agents, vascular endothelial growth agents, uterine relaxants, vitamins, or antigenic materials.

[0078] Other active agents include androgen inhibitors, polysaccharides, growth factors, hormones, antiangiogenesis factors, dextromethorphan, dextromethorphan hydrobromide, noscapine, carbetapentane citrate, chlophedianol hydrochloride, chlorpheniramine maleate, phenindamine tartrate, pyrilamine maleate, doxylamine succinate, phenyltoloxamine citrate, phenylephrine hydrochloride, phenylpropanolamine hydrochloride, pseudoephedrine hydrochloride, ephedrine, codeine phosphate, codeine sulfate morphine, mineral supplements, cholestyramine, N-acetylprocainamide, acetaminophen, aspirin, ibuprofen, phenyl propanolamine hydrochloride, caffeine, guaifenesin, aluminum hydroxide, magnesium hydroxide, peptides, polypeptides, proteins, amino acids, hormones, interferons, cytokines, and vaccines.

[0079] Representative drugs that can be used as active agents in the particles include, but are not limited to, peptide drugs, protein drugs, desensitizing materials, antigens, anti-infective agents such as antibiotics, antimicrobial agents, antiviral, antibacterial, antiparasitic, antifungal substances and combination thereof, antiallergenics, androgenic steroids, decongestants, hypnotics, steroidal anti-inflammatory agents, anticholinergics, sympathomimetics, sedatives, miotics, psychic energizers, tranquilizers, vaccines, estrogens, progestational agents, humoral agents, prostaglandins, analgesics, antispasmodics, antimalarials, antihistamines, cardioactive agents, nonsteroidal anti-inflammatory agents, antiparkinsonian agents, antihypertensive agents, p-adrenergic blocking agents, nutritional agents, and the benzophenanthridine alkaloids. The agent can further be a substance capable of acting as a stimulant, sedative, hypnotic, analgesic, anticonvulsant, and the like.

[0080] The particle can comprise a large number of active agents either singly or in combination. Other active agents include but are not limited to analgesics such as acetaminophen, acetylsalicylic acid, and the like; anesthetics such as lidocaine, xylocaine, and the like; anorexics such as dexedrine, phendimetrazine tartrate, and the like; antiarthritics such as methylprednisolone, ibuprofen, and the like; antiasthmatics such as terbutaline sulfate, theophylline, ephedrine, and the like; antibiotics such as sulfisoxazole, penicillin G, ampicillin, cephalosporins, amikacin, gentamicin, tetracyclines, chloramphenicol, erythromycin, clindamycin, isoniazid, rifampin, and the like; antifungals such as amphotericin B, nystatin, ketoconazole, and the like; antivirals such as acyclovir, amantadine, and the like; anticancer agents such as cyclophosphamide, methotrexate, etretinate, and the like; anticoagulants such as heparin, warfarin, and the like; anticonvulsants such as phenytoin sodium, diazepam, and the like; antidepressants such as isocarboxazid, amoxapine, and the like; antihistamines such as diphenhydramine HCI, chlorpheniramine maleate, and the like; hormones such as insulin, progestins, estrogens, corticoids, glucocorticoids, androgens, and the like; tranquilizers such as thorazine, diazepam, chlorpromazine HCI, reserpine, chlordiazepoxide HCI, and the like; antispasmodics such as belladonna alkaloids, dicyclomine hydrochloride, and the like; vitamins and minerals such as essential amino acids, calcium, iron, potassium, zinc, vitamin B 12 , and the like; cardiovascular agents such as prazosin HCI, nitroglycerin, propranolol HCI, hydralazine HCI, pancrelipase, succinic acid dehydrogenase, and the like; peptides and proteins such as LHRH, somatostatin, calcitonin, growth hormone, glucagon-like peptides, growth releasing factor, angiotensin, FSH, EGF, bone morphogenic protein (BMP), erythropoietin (EPO), interferon, interleukin, collagen, fibrinogen, insulin, Factor VIII, Factor IX, Enbrel®, Rituxam® , Herceptin , alpha- glucosidase, Cerazyme / Ceredose® , vasopressin, ACTH, human serum albumin, gamma globulin, structural proteins, blood product proteins, complex proteins, enzymes, antibodies, monoclonal antibodies, antibody fragments, and the like; prostaglandins; nucleic acids; carbohydrates; fats; narcotics such as morphine, codeine, and the like, psychotherapeutics; anti-malarias, L-dopa, diuretics such as furosemide, spironolactone, and the like; antiulcer drugs such as rantidine HCI, cimetidine HCI, and the like.

[0081] The active agent can also be an immunomodulator, including, for example, cytokines, interleukins, interferon, colony stimulating factor, tumor necrosis factor, and the like; allergens such as cat dander, birch pollen, house dust mite, grass pollen, and the like; antigens of bacterial organisms such as Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus, Streptococcus pyrogenes, Corynebacterium diphteriae, Listeria monocytogenes, Bacillus anthracis, Clostridium tetani, Clostridium botulinum, Clostridium perfringens. Neisseria meningitides, Neisseria gonorrhoeae, Streptococcus mutans. Pseudomonas aeruginosa, Salmonella ty phi, Haemophilus parainfluenzae, Bordetella pertussis, Francisella tularensis, Yersinia pestis, Vibrio cholerae, Legionella pneumophila, Mycobacterium tuberculosis, Mycobacterium leprae, Treponema pallidum, Leptspirosis interrogans, Borrelia burgdorferi, Campylobacter jejuni, and the like; antigens of such viruses as smallpox, influenza A and B, respiratory syncytial, parainfluenza, measles, HIV, SARS, varicella-zoster, herpes simplex 1 and 2, cytomeglavirus, Epstein-Barr, rotavirus, rhinovirus, adenovirus, papillomavirus, poliovirus, mumps, rabies, rubella, coxsackieviruses, equine encephalitis, Japanese encephalitis, yellow fever, Rift Valley fever, lymphocytic choriomeningitis, hepatitis B, and the like; antigens of such fungal, protozoan, and parasitic organisms such as Cryptococcuc neoformans, Histoplasma capsulatum, Candida albicans, Candida tropicalis, Nocardia asteroids, Rickettsia ricketsii, Rickettsia typhi, Mycoplasma pneumoniae, Chlamyda psittaci, Chlamydia trachomatis, Plasmodium falciparum, Trypanasoma brucei, Entamoeba histolytica, Toxoplasma gondii, Trichomonas vaginalis, Schistosoma mansoni, and the like. These antigens may be in the form of whole killed organisms, peptides, proteins, glycoproteins, carbohydrates, or combinations thereof. In a further specific aspect, the active agent comprises an antibiotic. The antibiotic can be, for example, one or more of Amikacin, Gentamicin, Kanamycin, Neomycin, Netilmicin, Streptomycin, Tobramycin, Paromomycin, Ansamycins, Geldanamycin, Herbimycin, Carbacephem, Loracarbef, Carbapenems, Ertapenem, Doripenem, Imipenem / Cilastatin, Meropenem, Cephalosporins (First generation), Cefadroxil, Cefazolin, Cefalotin or Cefalothin, Cefalexin, Cephalosporins (Second generation), Cefaclor, Cefamandole, Cefoxitin, Cefprozil, Cefuroxime, Cephalosporins (Third generation), Cefixime, Cefdinir, Cefditoren, Cefoperazone, Cefotaxime, Cefpodoxime, Ceftazidime, Ceftibuten, Ceftizoxime, Ceftriaxone, Cephalosporins (Fourth generation), Cefepime, Cephalosporins (Fifth generation), Ceftobiprole, Glycopeptides, Teicoplanin, Vancomycin, Macrolides, Azithromycin, Clarithromycin, Dirithromycin, Erythromycin, Roxithromycin, Troleandomycin, Telithromycin, Spectinomycin, Monobactams, Aztreonam, Penicillins, Amoxicillin, Ampicillin, Azlocillin, Carbenicillin, Cioxacillin, Dicloxacillin, Flucioxacillin, Mezlocillin, Meticillin, Nafcillin, Oxacillin, Penicillin, Piperacillin, Ticarcillin, Polypeptides, Bacitracin, Colistin, Polymyxin B, Quinolones, Ciprofloxacin, Enoxacin, Gatifloxacin, Levofloxacin, Lomefloxacin, Moxifloxacin, Norfloxacin, Ofloxacin, Trovafloxacin, Sulfonamides, Mafenide, Prontosil (archaic), Sulfacetamide, Sulfamethizole, Sulfanilimide (archaic), Sulfasalazine, Sulfisoxazole, Trimethoprim, Trimethoprim-Sulfamethoxazole (Co- trimoxazole) (TMP-SMX), Tetracyclines, including Demeclocycline, Doxycycline, Minocycline, Oxytetracycline, Tetracycline, and others; Arsphenamine, Chloramphenicol, Clindamycin, Lincomycin, Ethambutol, Fosfomycin, Fusidic acid, Furazolidone, Isoniazid, Linezolid, Metronidazole, Mupirocin, Nitrofurantoin, Platensimycin, Pyrazinamide, Quinupristin / Dalfopristin, Rifampicin (Rifampin in U.S.), Tinidazole, or a combination thereof. In one aspect, the active agent can be a combination of Rifampicin (Rifampin in U.S.) and Minocycline.

[0082] In one embodiment, the active agent is a therapeutic agent, or a salt or derivative thereof. Therapeutic agent derivatives may be therapeutically active themselves or they may be prodrugs, which become active upon further modification.

[0083] In one embodiment, therapeutic agents include any therapeutically effective agent or drug, such as antiinflammatory compounds, anti-depressants, stimulants, analgesics, antibiotics, birth control medication, antipyretics, vasodilators, anti-angiogenics, cytovascular agents, signal transduction inhibitors, cardiovascular drugs, e.g., anti-arrhythmic agents, vasoconstrictors, hormones, and steroids.

[0084] In one embodiment the therapeutic agent is an oncology drug, which may also be referred to as an antitumor drug, an anti-cancer drug, a tumor drug, an antineoplastic agent, or the like. Examples of oncology drugs that may be used according to the invention include, but are not limited to, adriamycin, alkeran, allopurinol, altretamine, amifostine, anastrozole, arsenic trioxide, azathioprine, bexarotene, biCNU, bleomycin, busulfan intravenous, busulfan oral, capecitabine (Xeloda), carboplatin, carmustine, CCNU, celecoxib, chlorambucil, cisplatin, cladribine, cyclosporin A, cytarabine, cytosine arabinoside, daunorubicin, Cytoxan, daunorubicin, dexamethasone, dexrazoxane, dodetaxel, doxorubicin, doxorubicin, DTIC, epirubicin, estramustine, etoposide phosphate, etoposide and VP-16, exemestane, FK506, fludarabine, fluorouracil, 5-FU, gemcitabine (Gemzar), gemtuzumab-ozogamicin, goserelin acetate, hydrea, hydroxyurea, idarubicin, ifosfamide, imatinib mesylate, interferon, irinotecan (Camptostar, CPT-111), letrozole, leucovorin, leustatin, leuprolide, levamisole, litretinoin, megastrol, melphalan, L-PAM, mesna, methotrexate, methoxsalen, mithramycin, mitomycin, mitoxantrone, nitrogen mustard, paclitaxel, pamidronate, Pegademase, pentostatin, porfimer sodium, prednisone, rituxan, streptozocin, STI-571 , tamoxifen, taxotere, temozolamide, teniposide, VM-26, topotecan (Hycamtin), toremifene, tretinoin, ATRA, valrubicin, velban, vinblastine, vincristine, VP16, and vinorelbine. Other examples of oncology drugs that may be used according to the invention are ellipticin and ellipticin analogs or derivatives, epothilones, intracellular kinase inhibitors and camptothecins.

[0085] In an embodiment the at least one active agent is selected from the group consisting of proteins, peptides, carbohydrates, nucleic acids and nucleic acid analogues, organic molecules having a molecular weight up to 1000 g / mol and combinations thereof.

[0086] Any known protein is in general suitable. Exemplarily proteins include glycoproteins and apolipoproteins. As used herein, the term "apolipoprotein" or "lipoprotein" refers to apolipoproteins known to those of skill in the art and variants and fragments thereof and to apolipoprotein agonists, analogues or fragments thereof as well as chimeric construction of an apolipoprotein. Apolipoproteins utilized in the invention also include recombinant, synthetic, semi- synthetic or purified apolipoproteins.

[0087] Any known peptide is in general suitable. The term peptide according to the present invention includes peptidomimetic. The peptide or peptidomimetic can be about 5 to 50 amino acids long, e.g., about 5, 10, 15, 20, 25, 30, 35, 40, 45, or 50 amino acids long. A "cell permeation peptide" is capable of permeating a cell, e.g., a microbial cell, such as a bacterial or fungal cell, or a mammalian cell, such as a human cell. A microbial cell-permeating peptide can be, for example, an a-helical linear peptide (e.g., LL-37 or Ceropin PI), a disulfide bond-containing peptide (e.g., a-defensin, p-defensin or bactenecin), or a peptide containing only one or two dominating amino acids (e.g., PR-39 or indolicidin). A cell permeation peptide can also include a nuclear localization signal (NLS). For example, a cell permeation peptide can be a bipartite amphipathic peptide, such as MPG, which is derived from the fusion peptide domain of HIV-1 gp41 and the NLS of SV40 large T.

[0088] In one embodiment, a targeting peptide tethered to an iRNA agent and / or the carrier oligomer can be an amphipathic a-helical peptide.

[0089] Peptide and peptidomimetic ligands include those having naturally occurring or modified peptides, e.g., D- or L-peptides; a-, p-, or y-peptides; N-methyl peptides; azapeptides; peptides having one or more amide, i.e., peptide, linkages replaced with one or more urea, thiourea, carbamate, or sulfonyl urea linkages; or cyclic peptides.

[0090] Any known carbohydrate is in general suitable. Exemplarily carbohydrates include dextran, pullulan, chitin, chitosan, inulin, cyclodextrin or hyaluronic acid.

[0091] In one embodiment the active agent is a nucleic acid or nucleic acid analogue, including, e.g., siRNA molecules, mRNA molecules, plasmids, micro RNA, antagomirs, aptamers, and ribozymes. Nucleic acids and nucleic acid analogues include polymers containing at least two deoxyribonucleotides or ribonucleotides in either single- or double- or triple-stranded form and includes DNA, RNA, and hybrids thereof. DNA may be in the form of linear DNA, circular DNA, plasmid DNA (pDNA), antisense molecules, PCR products, or vectors. RNA may be in the form of chemically modified or unmodified messenger RNA (mRNA), self-amplifying RNA (saRNA), circular RNA (circRNA) comprising at least one coding sequence, small hairpin RNA (shRNA), small interfering RNA (siRNA), micro RNA (miRNA), dicer substrate RNA, antisense oligonucleotide (ASO), transfer RNA (tRNA), single guide RNA (sgRNA) or viral RNA (vRNA) and combinations thereof. The nucleic acids may include one or more oligonucleotide modification.

[0092] In one embodiment the at least one active agent is an organic molecule having a molecular weight up to 1000 g / mol, also referred to as small molecule in the pharmaceutical field, preferably the organic molecule is selected from paclitaxel, doxorubicin, irinotecan, vincristine and oxaliplatin.

[0093] Additionally, at least one of the following additives can be further present in the composition: preservatives (such as octadecyldimethylbenzyl ammonium chloride; hexamethonium chloride; benzalkonium chloride, benzethonium chloride; phenol, butyl or benzyl alcohol; alkyl parabens such as methyl or propyl paraben; catechol; resorcinol; cyclohexanol; 3-pentanol; and m-cresol); low molecular weight (less than about 10 residues) polypeptides; proteins, such as serum albumin, gelatin, or immunoglobulins; hydrophilic polymers such as polyvinylpyrrolidone; amino acids such as glycine, glutamine, asparagine, histidine, arginine, or lysine; carbohydrates including monosaccharides, disaccharides, and other sugar compounds like glucose, mannose, or dextrins; chelating agents such as EDTA; sugars such as sucrose, mannitol, trehalose or sorbitol; salt-forming counter-ions such as sodium; metal complexes (e.g., Zn-protein complexes), vehicles, binders, disintegrants, immunological adjuvants like a cell penetrating peptide, for example human lactoferrin protein or a fragment thereof, Tat, Ant, Rev, FHV, HSV-1 protein VP22, C6, C6M1 , PF20, NAP, POD, polyarginine, polylysine, PTD-5, Transportan, MAP, TP10, Pep-7, Azurin p18, Azurin p28, hCT18- 32, Bac 7, CTP, K5-FGF, HAP-1 , 293P-1 , KALA, GALA, LAH4-L1 , Melittin, Penetratin, EB1 , MPG, CADY, Pep4, preferably a human lactoferrin protein or a fragment thereof, fillers (diluents), lubricants, glidants (flow enhancers), compression aids, colors, sweeteners, suspending / dispersing agents, film formers / coatings, flavors, printing inks.

[0094] In one embodiment the at least one additive is present in 0.0001 to 5 wt.-%, preferably 0.01 to 4 wt.-%, more preferably 0.1 to 3 wt.-% based on the total weight of the particle.

[0095] In one embodiment the nanoparticle has a mean diameter of 20 to 500 nm, preferably 30 to 400, more preferably 50 to 250 nm, preferably measured via dynamic light scattering, more preferably according to ISO 22412:2017. The measurements can be conducted with a Malvern Zetasizer NanoZS.

[0096] In one embodiment the particle can comprise 1 %, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95% by weight active agent, relative to the total weight of the particle, including any range between the disclosed percentages. Furthermore, the present invention refers to a method of producing a particle according to the present invention comprising or consisting of the steps: i) dissolving at least one block copolymer according to any of claims 1 to 7 or a block copolymer obtained by the method according to claim 8 in an organic solvent in order to obtain a dispersed phase; ii) dissolving at least one stabilizer, such as polyvinyl alcohol (PVA), in water, preferably deionized water, in order to obtain a continuous phase;

[0097] Hi simultaneously pumping the dispersed phase and the continuous phase into a sonicator in order to obtain an emulsion; iv) extracting the emulsion, inline, into a stream of water, preferably deionized water in order to obtain the particles. providing an aqueous solution comprising at least one block copolymer according to the present invention or a block copolymer obtained by the method according to the present invention.

[0098] The particles of the present invention are administered in a therapeutically effective amount, which will vary depending upon a variety of factors including the activity of the specific therapeutic agent employed; the metabolic stability and length of action of the therapeutic agent; the age, body weight, general health, sex, and diet of the patient; the mode and time of administration; the rate of excretion; the drug combination; the severity of the particular disorder or condition; and the subject undergoing therapy.

[0099] In a preferred embodiment the particles of the present invention is a pharmaceutical particles for the treatment of illness in humans. In a further preferred embodiment, the particle of the present invention is a pharmaceutical composition for the treatment of illness in mammals.

[0100] Medical device comprising at least one block copolymer according to the present invention or at least one block copolymer obtained by the method according to the present invention. In one embodiment the medical device is an implantable medical device. In one embodiment the medical device is selected from catheters, sutures, staples, surgical clips, and implants.

[0101] It is well known to the skilled person in the medical device field how to obtain a medical device from a suitable block copolymer, like the block copolymer according to the present invention. For example Manavitehrani, Iman et al. “Biomedical Applications of Biodegradable Polyesters.” Polymers vol. 8,1 20. discloses methods to obtain a medical device. Examples

[0102] Reagents and chemicals

[0103] Reagents and chemicals were purchased from TCI (Tokio, Japan), Thermo Fisher Scientific (Waltham, MA, USA), Carl Roth GmbH (Karlsruhe, Germany) and Merck KGaA (Darmstadt, Germany) unless otherwise noted. Ethylene oxide (EG) was obtained from Air Liquide (Paris, France). Tetra hydrofuran (THF) was flashed over basic aluminum oxide before usage. Glycidyl methyl ether (GME) was dried over Calcium hydride (CaH2) and cryo-transferred before polymerization. mPEO5k was obtained Pharmicell Co. Ltd (Seoul, South Korea).

[0104] Synthesis of poly(ethylene oxide)s

[0105] Example 1 : Synthesis of glycidyl methyl ether (GME)

[0106] 1-Chloro-3-methoxy-propan-2-ol (50.0 g, 401 mmol) was added to a flask equipped with a magnetic stirrer and cooled with an ice bath. Finely grounded sodium hydroxide (NaOH, 20.9 g, 522 mmol) was added in portions under stirring. After complete reaction (TLC control) the crude product was cryotransferred in vacuo from the reaction flask and dried over CaH2 under cooling with an ice bath. After an additional cryo-transfer and filtration step, GME (30.1 g, 85%) was obtained as a colorless liquid.

[0107] Example 2: Synthesis of 1-methoxy-3-(2-methoxyethoxy)propan-2-ol

[0108] Ethylene oxide monomethyl ether (8.64 g, 9.00 mL, 1 13 mmol) was added to a flask equipped with a reflux condenser. NaOH solution (19 M, 3 mL) was added under stirring and the resulting solution was heated to 55 °C. GME (5.00 g, 5.10 mL, 56.7 mmol) was added and the solution was stirred overnight. The solution was cooled to room temperature and extracted with dichloromethane (DCM, 50 mL) three times. The combined organic phases were dried over magnesium sulphate (MgSC ). After filtration, the solvent was evaporated under reduced pressure. 1-Methoxy-3-(2-methoxyethoxy)propan-2-ol (3.74 g, 40%) was obtained as a colorless liquid after fractional distillation of the residue. Example 3: Synthesis of mP(EO67-co-GME38)

[0109] KOtBu (98.0 mg, 877 pmol) was dissolved in stabilizer-free THF and small quantities of Millipore water and transferred into a flame-dried and argon flushed flask equipped with a Teflon stopcock and a septum. 1 Methoxy 3-(2-methoxyethoxy)propan-2-ol (147 mg, 895 pmol) was dissolved in benzene and transferred into the flask. High vacuum was applied to the flask and the solvents were removed under high vacuum. The resulting initiator salt was dried under high vacuum at 55 °C overnight. The residue was dissolved in dry DMSO (34 mL). After freezing the resulting solution at -80 °C, GME (1 .58 g, 1 .61 mL, 17.9 mmol) was added to the flask via syringe. EG (1 .40 g, 1 .44 mL, 31 .8 mmol) was added to the flask via cryo-transfer from a graduated ampoule. The cooling bath was removed, and the reaction mixture was stirred for 1 d at 30 °C under high vacuum. The solution was cooled to -80 °C and GME (1 .58 g, 1 .61 mL, 17.9 mmol) was added to the flask via syringe. EO (1 .40 g, 1 .44 mL, 31 .8 mmol) was added to the flask via cryo-transfer from a graduated ampoule. The cooling bath was removed, and the reaction mixture was stirred for 1 d at 30 °C under high vacuum. The solvent was evaporated under high vacuum at 50 °C. Millipore water (100 mL) and acidic ion-exchange resin (DOVVEX) (500 mg) were added to the residue. The resulting suspension was stirred overnight. The suspension was filtered, and the resulting solution was lyophilized. The residue was dissolved in diethyl ether (400 mL). The resulting suspension was filtered, and the organic phase was dried over MgSC . After a filtration step, the solvent was evaporated to yield mP(EO67-co-GME3s) (96%, PDI = 1 .08) as a viscous liquid.

[0110] Copolymers were characterized by nuclear magnetic resonance (NMR) spectroscopy, size exclusion chromatography (SEC), and matrix-assisted laser-desorption-ionization time of flight mass spectroscopy (MALDI-TOF):

[0111] 1H NMR spectra were recorded on a Bruker (Billerica, MA, U.S.) Ill HD 300 spectrometer with 300 MHz and referenced internally to residual proton signals of the deuterated solvent.

[0112] SEC: Mw, Mnand dispersities (Mw / Mn= D) of all samples were determined from the corresponding size exclusion chromatograms (refractive index (Rl) detector, calibration with PEO standards). SEC measurements were performed with dimethylformamide (DMF with 1 g / L lithium bromide (LiBr)) as the mobile phase (flow rate 1 mL / min) on poly(2-hydroxyethylmethacrylat) (PHEMA) 300 / 100 / 40 columns at 50 °C. Polymer concentrations were 1 mg / mL. Calibration was carried out using PEO standards (from Polymer Standard Service, Mainz, Germany).

[0113] MALDI-TOF MS measurements were carried out at a Bruker autoflex maX MALDI-TOF / TOF. The potassium salt of trifluoroacetic acid and trans 2 [3-(4-tert-butylphenyl)-2-methyl-2- propenylidene]malononitrile (DCTB) were used as ionization salt and matrix, respectively. Data was used to calculate Mnof the polymer and degree of polymerization (DP) for the respective comonomers.

[0114] Table 1 : Characterization of mP(EO67-co-GME38)

[0115] DPn.GME.MALDI 38

[0116] DPn.EO. MALDI 67

[0117] Mn.sEc [kDa] 5.2

[0118] Mn.MALDi [kDa] 6.3

[0119] DSEC.RI 1 .08

[0120] Example 4: Determination of immunogenicity of po poly(ethylene oxide)s by competitive enzyme-linked immunosorbent assay (ELISA)

[0121] The interaction of mP(EO67-co-GME3s) from Example 3 and mPEO5k with anti-PEG antibodies (APAs) was evaluated by a competitive PEG ELISA kit using a murine monoclonal, horseradish peroxidase conjugated anti PEO antibody (HRP anti-PEO, Life diagnostics, West Chester, PA, USA). Samples of concentrations ranging from 0 to 4600 pg mL-1were prepared in dilution buffer. 50 pL of each prepared sample was dispensed to a PEO pre-coated 96-well plate and 50 pL of HRP anti-PEO was added to each well. The solutions were incubated for 1 h at 25 °C with a micro-plate shaker and then washed six times with 400 pL of wash buffer per each well. After removal of residual droplets, 100 pl of 3,3',5,51-Tetramethylbiphenyl-4,4'-diamine was added to each well and the solutions were mixed on a micro-plate shaker for 20 min. The reaction was stopped by addition of 100 pL of stop solution and the absorbance at 450 nm was read within 5 min.

[0122] Analysis of ELISA Data: The determined absorbance values were normalized to visualize the percent of maximal binding. The sample concentrations were transformed to a function of log 10. The sigmoidal fits were calculated using the following equation with a representing the upper, b the lower limit, c the inflection point and d the hill slope. y = a + (b-a) / 1 + 10(c x)*d

[0123] Fig. 1 shows the ELISA test result of mP(EO67-co-GME3s) from Example 3 and mPEO5k. Figure shows the function of the normalized absorption at a wavelength of 450 nm versus the logio function of the polymer concentration in nanograms per mL, therefore illustrating the APA interaction with the investigated polymers at various concentrations. Interaction of the polymers with the APA reduces the adsorption. The ELISA data shows a strong influence of the methoxy methyl side chains on the interaction of polymer with the APA (it is important to note that the x-axis has a logarithmic scale). With the incorporation of sterically demanding methoxy methyl side groups into the polyether structure, significantly higher polymer concentrations are necessary to observe interactions between the polymer and the APA. Synthesis of block copolymers

[0124] Example 5: Synthesis of mP(EO67-co-GME3s)-PDLA15k block copolymer mP(EO67-co-GME38)-PDLA15k was synthesized via ring-opening polymerization (ROP) of D,L-Lactide at 140 °C using m(EO67-co-GME3s) from Example 3 as the macroinitiator. Briefly, 0.889 g (0.13 mmol) mP(EO67-co-GME38) and 2.113 g (41 .66 mmol) D,L-Lactide were combined in a 7.4 mL septum sealed vial and melted at 140 °C under N2 utilizing a block heater. Simultaneously, a second polymerization (comparative example) was prepared as a control using mPEO5k as the macroinitiator, targeting an identical lactide / initiator mol ratio. Once molten, 75 pL of a 100 mg / mL Sn(Oct)2 solution in toluene was added to each vial to afford a catalyst concentration of 2.5 ppt. To promote mixing, the vials were manually inverted approximately every 5 min for the first 30 min of the polymerization. The reactions were allowed to proceed for 18 h, after which vacuum stripping was performed for an additional 2 h at 140 °C. The products were recovered by removing the vials from the heating block without further purification.

[0125] Polymers were characterized via1H NMR using a Varian (Palo Alto, CA, U.S.) INOVA 400 MHz NMR spectrometer in CDCI3 using a delay time of 5 s. rPEG copolymer composition was determined by comparing the p(D,L-Lactide) methine resonances at 5.20 ppm and rPEG methylene and methine resonances at 3.40-3.85 ppm to the rPEG methoxy resonances at 3.38 ppm. mPEO copolymer compositions were determined by comparing the p(D,L-Lactide) methine resonances at 5.20 ppm and monomethoxy PEG (mPEO) methylene resonances at 3.65 ppm to the mPEO methoxy end group resonance at 3.38 ppm.

[0126] Table 2: Characterization of block copolymer molecular weight by1H NMR _

[0127] Entry / Wn, PEC, NMR A n.PDLA.NMR Mn, Copolymer, NMR

[0128] Sample

[0129] (Example) [kDa] [kDa] [kDa] a(5) mP(EO67-co-GME38)-PDLA15k 7.1 15.4 22.6 b(5)* mPEO5k-PDLA15k 4.9 14.6 19.5

[0130] * Comparative Example

[0131] Thermal analysis of polymers was carried out by differential scanning calorimetry (DSC) using a TA Instruments (Waters Corp., New Castle, DE, US) DSC 250 according to ASTM D 3418. The thermal history of the samples was excluded via three cooling and three heating cycles: Cooling: Ramp 10 K / min to -75 °C

[0132] Isothermal for 1 min

[0133] Heating: Ramp 10 K / min to 200 °C

[0134] Isothermal for 1 min

[0135] Cooling: Ramp 5 K / min to -75 °C

[0136] Isothermal for 1 min

[0137] Heating: Ramp 5 K / min to 200 °C

[0138] Isothermal for 1 min

[0139] Cooling: Ramp 5 K / min to -75 °C

[0140] Isothermal for 1 min

[0141] Heating: Ramp 10 K / min to 200 °C

[0142] For each sample, the glass transition temperature (Tg) was obtained from the third heating curve.

[0143] Fig. 2 shows the thermogram of polymers a(5) and b(5). a(5) exhibits one Tgat -1 °C. This indicates miscibility of the two polymer phases. b(5) exhibits two glass transition temperatures: -3 °C for the PEO and 48 °C for the PDLA segment. This indicates phase separation of the two polymer phases.

[0144] Preparation of nanoparticles (NPs)

[0145] Example 6: Preparation of NPs by inline sonication / emulsion process

[0146] Polymer solutions (dispersed phase) were prepared at 10 %(w / w) in ethyl acetate. Samples were placed into a water bath at 30 °C for 1 min to ensure entire dissolution. Polymer solutions were filtered via a 0.45 pm PTFE syringe filter. The continuous phase consisted of a 1%(w / w) polyvinyl alcohol (PVA) solution (PVA 5-88, Merck KGaA Darmstadt, Germany). The dispersed phase was pumped into the sonicator via a syringe and syringe pump and the continuous phase was pumped via an ISCO piston pump at 4 mL / min and 12 mL / min, respectively. The sonicator was operated at 100% amplitude. The emulsion was continuously extracted, inline, into a stream of deionized water pumped via a peristaltic pump at 240 mL / min. The resultant nanosuspension was collected in a beaker and stirred openly in the fume hood for 10 min before use.

[0147] Mean diameter (z-ave.) and zeta potential (z-pot.) of NPs were measured with a Zetasizer NanoZS from Malvern Instruments GmbH (Herrenberg, Germany). A DTS 1070 clear disposable folded capillary cell from Malvern Panalytical GmbH (Kassel, Germany) was used. Z-ave. and the width of the fitted Gaussian distribution, which is displayed as the polydispersity index (PDI), were calculated from data of at least 10 runs. Measurements were carried out in triplicate and results are presented as mean average ± standard deviation. Table 3: Z-ave., PDI and z-pot. of NPs

[0148] Entry Z-ave. PDI z-pot.

[0149] Polymer used

[0150] (Example) [nm] [mV] a(5) mP(EO67-co-GME38)-PDLA15k 147.6±2.1 0.226±0.008 -6.6±0.1 b(5)* mPEO5k-PDLA15k 125.2±0.9 0.144±0.008 -11.4±1.0

[0151] * Comparative Example

[0152] Conclusion

[0153] A new class of block copolymers comprising a PEO with C1 to C3-alkyloxymethyl side chains block and a hydrophobic block. mP(EO-co-GME) was manufactured by anionic ring opening polymerization (AROP).

[0154] ELISA assay revealed significantly weaker binding affinity of mP(EO-co-GME) towards APAs compared to PEO. mP(EO-co-GME) was used as macroinitiator for the ROP of D,L-Lactide. DSC revealed different polymer phase separation and thermal properties of the mP(EO-co-GME)-PDLA block copolymer compared to the mPEO-PDLA block copolymer: mP(EO-co-GME)-PDLA exhibits one Tg, indicating miscibility of the two polymer phases. mPEO-PDLA exhibits two Tgs, indicating phase separation. Block copolymers were used for the preparation of nanoparticles by inline sonication / emulsion. Both polymers resulted in monomodally distributed nanosuspensions. Z-ave. diameters for the rPEG and PEO block copolymers were 147.6±2.1 and 125.2±0.9 nm, respectively.

Claims

Claims1 . A block copolymer obtained by reacting at least one monomer, preferably one or two monomers, selected from L-lactide, D-lactide, DL- lactide, epsilon-caprolactone, trimethylene carbonate, delta-valerolactone, alpha-methylene-delta- valerolactone, 3,9-diethyliden-2,4,8,10-tetraoxaspiro(5.5)undecane, aspartic acid, glutamic acid, glycolide, and para-dioxanone; with a prepolymer H-[A]-R1; wherein [A] is a polyoxyalkylene group comprising at least one unitand at least one unit selected from the group ofR1is selected from -H; -OH; -SH; -NH2; -NHR2, -NR3R4, -OR5, -SR5or linear, branched or cyclic alkyl groups having up to 20 carbon atoms; and whereinR2to R5are independently selected from linear, branched or cyclic alkyl groups having up to 20 carbon atoms, in which up to 5 carbon atoms can be substituted with an oxygen or a sulfur atom; in the presence of a catalyst.

2. The block copolymer according to claim 1 , wherein the block copolymer has a number average molecular weight of 1 ,200 to 600,000 g / mol, preferably 2,000 to 250,000 g / mol, more preferably5,000 to 100,000 g / mol, preferably determined via size exclusion chromatography using a refractive index (Rl) detector and polyethylene oxide standards.

3. The block copolymer according to any of the preceding claims, wherein the catalyst is a ring opening catalyst or a polycondensation catalyst, preferably the ring opening catalyst is a tin catalyst, more preferably tin (II) 2-ethylhexanoate, or preferably the polycondensation catalyst is an organic acid, more preferably p-toluenesulfonic acid.

4. The block copolymer according to any of the preceding claims, wherein the at least one monomer, preferably one or two monomers, is selected from L-lactide, D-lactide, DL-lactide, epsilon- caprolactone, trimethylene carbonate, delta-valerolactone, alpha-methylene-delta-valerolactone, glycolide, and para-dioxanone, preferably from L-lactide, D-lactide, DL-lactide, epsilon- caprolactone, and glycolide, more preferably from L-lactide, D-lactide, DL-lactide, and glycolide.

5. The block copolymer according to any of the preceding claims, wherein H-[A]-R1has a number average molecular weight of 200 to 200,000 g / mol, preferably 500 to 100,000 g / mol, more preferably 1 ,000 to 50,000 g / mol, preferably determined via size exclusion chromatography using a refractive index (Rl) detector and polyethylene oxide standards.

6. The block copolymer according to any of the preceding claims wherein the polyoxyalkylene group [A] comprises or consist of at least one unit7. The block copolymer according to any of the preceding claims, wherein R1is -OR5, preferably wherein R5is selected from linear, branched or cyclic alkyl groups having up to 20 carbon atoms, in which up to 5 carbon atoms can be substituted with an oxygen atom.

8. A method of producing a block copolymer, preferably according to any of claims 1 to 7, comprising or consisting of the steps: providing a prepolymer H-[A]-R1; wherein [A] is a polyoxyalkylene group comprising at least one unitand at least one unit selected from the group ofereinR1is selected from -H; -OH; -SH; -NH2; -NHR2, -NR3R4, -OR5, -SR5or linear, branched or cyclic alkyl groups having up to 20 carbon atoms; and whereinR2to R5are independently selected from linear, branched or cyclic alkyl groups having up to 20 carbon atoms, in which up to 5 carbon atoms can be substituted with an oxygen or a sulfur atom; and allowing the prepolymer to react with at least one monomer, preferably one or two monomers, selected from L-lactide, D-lactide, DL-lactide, epsilon-caprolactone, trimethylene carbonate, delta- valerolactone, alpha-methylene-delta-valerolactone, 3,9-diethy liden-2,4,8, 10- tetraoxaspiro(5.5)undecane, aspartic acid, glutamic acid, glycolide, and para-dioxanone; in the presence of a catalyst.

9. A particle, preferably a nanoparticle, comprising at least one block copolymer according to any of claims 1 to 7 or at least one block copolymer obtained by the method according to claim 8.

10. The nanoparticle according to claim 9 further comprising at least one active agent and optionally at least one additive.11 . The nanoparticle according to claim 9 or 10, wherein the nanoparticle has a mean diameter of 20 to 500 nm, preferably 30 to 400, more preferably 50 to 250 nm, preferably measured via dynamic light scattering, more preferably according to ISO 22412:2017.

12. A method of producing a particle according to any of claims 9 to 11 comprising or consisting of the steps: i) dissolving at least one block copolymer according to any of claims 1 to 7 or a block copolymer obtained by the method according to claim 8 in an organic solvent in order to obtain a dispersed phase; ii) dissolving at least one stabilizer, such as polyvinyl alcohol (PVA), in water, preferably deionized water, in order to obtain a continuous phase; iii) simultaneously pumping the dispersed phase and the continuous phase into a sonicator in order to obtain an emulsion; iv) extracting the emulsion, inline, into a stream of water, preferably deionized water in order to obtain the particles.

13. Particle according to claim 11 for the treatment of an illness in humans.

14. Particle according to claim 11 for the treatment of an illness in mammals.

15. Medical device comprising at least one block copolymer according to any of claims 1 to 7 or at least one block copolymer obtained by the method according to claim 8.

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