Methods for preparing polymeric DYES with drug conjugates

Abstract

Method for preparing polymer-drug conjugates containing both biologically active moieties and fluorescent or colored dyes is provided. The method includes reacting a compound of structure (I): Formula (I) with an amine-containing biologically active compound of structure (11): M2-NHR8, wherein G comprises a group which is capable of forming a covalent bond with an amine group and R1, R2, R3, R4, R5, R6, R7, R8, L1, L2, L3, L 4, L 5, L6, L7, M1, m, n, p, and w are as defined herein.

Description

[0001] METHODS FOR PREPARING POLYMERIC DYES WITH DRUG CONJUGATES

[0002] BACKGROUND

[0003] Field

[0004] Embodiments of the present disclosure are generally directed to methods for preparing polymer-drug conjugates having both fluorescent or colored moieties and biologically active moieties.

[0005] Description of the Related Art

[0006] Targeted drug conjugates, unlike, e.g., chemotherapy, deliver drugs to target cells, with little or no off-target activity. Typically, targeted drug conjugates comprise a targeting molecule that is linked to a biologically active payload or drug. By combining the unique targeting capability with the therapeutic effectiveness of a biologically active drug, conjugates can deliver the drug only to the intended target and minimize potential side effects. Polymer-drug conjugates (PDCs) are one class of targeted drug conjugates that are of particular interest for treatments of various diseases. Polymer conjugates are found to be capable of improving the pharmacokinetic parameters of the drugs, increasing the drug stability against degradation, providing high loading capacity, and sustained release patterns, as well as avoiding premature drug release. Polymer-drug conjugates integrated with an imaging agent are attractive due to the capability of providing both therapy and diagnosis or imaging functions. PDCs integrated with an imaging agent helps to monitor the drug’s biodistribution and localization, which aid in a precise activation of a therapeutic response.

[0007] There remains a need in the art for developing methods for preparation of polymer-drug conjugates with therapeutic drugs and imaging agents on the same polymer backbone to permit simultaneous diagnosis / imaging as the progression of the drug treatment. The present disclosure fulfills this need and provides further related advantages.

[0008] BRIEF SUMMARY

[0009] In brief, embodiments of the present disclosure are generally directed to methods for preparing polymer-drug conjugates.

[0010] In some embodiments, a method for preparing a polymer-drug conjugate that permits simultaneous diagnosis and treatment options is provided. The method comprises reacting a compound of structure (I): with a compound of structure (II):

[0011] M2— NHR8

[0012] (II) wherein R1, R2, R3, R4, R5, R6, R7, R8, L1, L2, L3, L4, L5, L6, L7, G, M1, M2, m, n, p, and w are as defined herein.

[0013] In some embodiments, a compound of structure (I) is provided The compound of structure (I) has the following structure: wherein R1, R2, R3, R4, R5, R6, R7, L1, L2, L3, L4, L5, L6, L7, G, M1, m, n, p, and w are as defined herein.

[0014] In some embodiments, a compound of structure (III) that is formed by reacting a compound of structure (I) with a compound of structure (II) is provided. The compound of structure (III) has the following structure: wherein R1, R2, R3, R4, R5, R6, R7, L1, L2, L3, L4, L5, L6, L7, M1, M2, m, n, p, and w are as defined herein.

[0015] In some embodiments, a compound of structure (V) that is usable as an intermediate for preparing a compound of structure (I) is provided. The compound of structure (V) has the following structure: wherein R1, R2, R3, R4, R5, R6, R7, L1, L2, L3, L4, L5, L6, L7, G, G1, m, n, p, and w are as defined herein.

[0016] In some embodiments, a method for preparing a compound of structure (I) is provided, the method comprising reacting a compound of structure (V) with a compound of M1-G1, wherein M1-G1are as defined herein.

[0017] These and other aspects of the disclosure will be apparent upon reference to the following detailed description.

[0018] DETAILED DESCRIPTION

[0019] In the following description, certain specific details are set forth in order to provide a thorough understanding of various embodiments of the disclosure. However, one skilled in the art will understand that the disclosure may be practiced without these details.

[0020] Unless the context requires otherwise, throughout the present specification and claims, the word "comprise" and variations thereof, such as, "comprises" and "comprising" are to be construed in an open, inclusive sense, that is, as "including, but not limited to".

[0021] Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0022] "Amino" refers to the -NH2 group.

[0023] "Carboxy" refers to the -CO2H group.

[0024] "Cyano" refers to the -CN group.

[0025] "Formyl" refers to the -C(=O)H group.

[0026] "Hydroxy" or "hydroxyl" refers to the -OH group.

[0027] "Imino" refers to the =NH group. "Nitro" refers to the -NO2 group.

[0028] "Oxo" refers to the =0 substituent group.

[0029] "Sulfhydryl" refers to the -SH group.

[0030] "Thioxo" refers to the =S group.

[0031] "Alkyl" refers to a straight or branched hydrocarbon chain group consisting solely of carbon and hydrogen atoms, containing no unsaturation, having from one to twelve carbon atoms (Ci-C 12 alkyl), one to eight carbon atoms (Ci-Cs alkyl) or one to six carbon atoms (Ci-Ce alkyl), and which is attached to the rest of the molecule by a single bond, e.g., methyl, ethyl, / / -propyl,

[0032] 1-methylethyl (Ao-propyl), / / -butyl, / / -pentyl, 1 , 1 -dimethylethyl ( / -butyl), 3 -methylhexyl,

[0033] 2-methylhexyl, and the like. Unless stated otherwise specifically in the specification, alkyl groups are optionally substituted.

[0034] "Alkylene" or "alkylene chain" refers to a straight or branched divalent hydrocarbon chain linking the rest of the molecule to a radical group, consisting solely of carbon and hydrogen, containing no unsaturation, and having from one to twelve carbon atoms, e.g., methylene, ethylene, propylene, / / -butylene, ethenylene, propenylene, / / -butenylene, propynylene, / / -butynylene, and the like. The alkylene chain is attached to the rest of the molecule through a single bond and to the radical group through a single bond. The points of attachment of the alkylene chain to the rest of the molecule and to the radical group can be through one carbon or any two carbons within the chain. Unless stated otherwise specifically in the specification, alkylene is optionally substituted.

[0035] "Alkenylene" or "alkenylene chain" refers to a straight or branched divalent hydrocarbon chain linking the rest of the molecule to a radical group, consisting solely of carbon and hydrogen, containing at least one carbon-carbon double bond and having from two to twelve carbon atoms, e.g., ethenylene, propenylene, / / -butenylene, and the like. The alkenylene chain is attached to the rest of the molecule through a single bond and to the radical group through a double bond or a single bond. The points of attachment of the alkenylene chain to the rest of the molecule and to the radical group can be through one carbon or any two carbons within the chain. Unless stated otherwise specifically in the specification, alkenylene is optionally substituted.

[0036] "Alkynylene" or "alkynylene chain" refers to a straight or branched divalent hydrocarbon chain linking the rest of the molecule to a radical group, consisting solely of carbon and hydrogen, containing at least one carbon-carbon triple bond and having from two to twelve carbon atoms, e.g., ethynylene, propynylene, / / -butynylene, and the like. The alkynylene chain is attached to the rest of the molecule through a single bond and to the radical group through a double bond or a single bond. The points of attachment of the alkynylene chain to the rest of the molecule and to the radical group can be through one carbon or any two carbons within the chain. Unless stated otherwise specifically in the specification, alkynylene is optionally substituted.

[0037] "Alkylether" refers to any alkyl group as defined above, wherein at least one carboncarbon bond is replaced with a carbon-oxygen bond. The carbon-oxygen bond may be on the terminal end (as in an alkoxy group) or the carbon oxygen bond may be internal (i.e., C-O-C). Alkylethers include at least one carbon oxygen bond, but may include more than one. For example, polyethylene glycol (PEG) is included within the meaning of alkylether. Unless stated otherwise specifically in the specification, an alkylether group is optionally substituted. For example, in some embodiments an alkylether is substituted with an alcohol or -OP(=Ra)(Rb)Rc, wherein each of Ra, Rb and Rc is as defined for compounds of structure (I), (III), and (V).

[0038] "Alkoxy" refers to a group of the formula -ORa where Rais an alkyl group as defined above containing one to twelve carbon atoms. Unless stated otherwise specifically in the specification, an alkoxy group is optionally substituted.

[0039] "Alkoxyalkylether" refers to a group of the formula -ORaRb where Ra is an alkylene group as defined above containing one to twelve carbon atoms, and Rb is an alkylether group as defined herein. Unless stated otherwise specifically in the specification, an alkoxyalkylether group is optionally substituted, for example substituted with an alcohol or -OP(=Ra)(Rb)Rc, wherein each of Ra, Rb and Rc is as defined for compounds of structure (I), (III), and (V).

[0040] "Heteroalkyl" refers to an alkyl group, as defined above, comprising at least one heteroatom (e.g., N, O, P or S) within the alkyl group or at a terminus of the alkyl group. In some embodiments, the heteroatom is within the alkyl group (i.e., the heteroalkyl comprises at least one carbon-[heteroatom]x-carbon bond, where x is 1, 2 or 3). In other embodiments, the heteroatom is at a terminus of the alkyl group and thus serves to join the alkyl group to the remainder of the molecule (e.g., Ml-H-A), where Ml is a portion of the molecule, H is a heteroatom and A is an alkyl group). Unless stated otherwise specifically in the specification, a heteroalkyl group is optionally substituted. Exemplary heteroalkyl groups include ethylene oxide (e.g., polyethylene oxide), optionally including phosphorous-oxygen bonds, such as phosphodiester bonds. "Heteroalkoxy" refers to a group of the formula -ORa where Ra is a heteroalkyl group as defined above containing one to twelve carbon atoms. Unless stated otherwise specifically in the specification, a heteroalkoxy group is optionally substituted.

[0041] "Heteroalkylene" refers to an alkylene group, as defined above, comprising at least one heteroatom (e.g., Si, N, O, P or S) within the alkylene chain or at a terminus of the alkylene chain. In some embodiments, the heteroatom is within the alkylene chain (z.e., the heteroalkylene comprises at least one carbon-[heteroatom]-carbon bond, where x is 1, 2 or 3). In other embodiments, the heteroatom is at a terminus of the alkylene and thus serves to join the alkylene to the remainder of the molecule (e.g., M1-H-A-M2, where Ml and M2 are portions of the molecule, H is a heteroatom and A is an alkylene). Unless stated otherwise specifically in the specification, a heteroalkylene group is optionally substituted. Exemplary heteroalkylene groups include ethylene oxide (e.g., polyethylene oxide) and the "C," "HEG," and "PEG IK" linking groups illustrated below:

[0042] Multimers of the above C-linker, HEG linker and / or PEG IK linker are included in various embodiments of heteroalkylene linkers. In some embodiments of the PEG IK linker, n ranges from 19-25, for example n is 19, 20, 21, 22, 23, 24, or 25. Multimers may comprise, for example, the following structure: wherein x is 0 or an integer greater than 0, for example, x ranges from 0-100 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10).

[0043] A "linker" refers to a contiguous chain of at least one atom, such as carbon, oxygen, nitrogen, sulfur, phosphorous, and combinations thereof, which connects a portion of a molecule to another portion of the same molecule or to a different molecule, moiety or solid support (e.g., microparticle). Linkers may connect the molecule via a covalent bond or other means, such as ionic or hydrogen bond interactions. In some embodiments, the linker is a heteroatomic linker (e.g., comprising 1-10 Si, N, O, P, or S atoms), a heteroalkylene (e.g., comprising 1-10 Si, N, O, P, or S atoms and an alkylene chain) or an alkylene linker (e.g., comprising 1-12 carbon atoms). In some embodiments, a heteroalkylene linker comprises the following structure: wherein: x9and x10are each independently a integer greater than 0. In some embodiments, the heteroatomic linker is -O-, -S-, or -OP(=O)O’-O- In some embodiments, the heteroalkylene linker comprises -OP(=O)O -O- In some embodiments, the heteroalkylene linker comprises at least one S-S bond.

[0044] "Physiologically cleavable linker" refers to a molecular linkage that can be split or separated a prescribed manner, resulting in two or more separate molecules while in the presence of an in vivo or in vitro environment of an organism or cell system. Generally, physiological conditions that induce such a cleavage or scission event may include a temperature ranging from about 20 to 40°C, an atmospheric pressure of about 1 atm (101 kPa or 14.7 psi), a pH of about 6 to 8, a glucose concentration of about 1 to 20 mM, atmospheric oxygen concentration, and earth gravity. In some embodiments, physiological conditions include enzymatic conditions (z.e., enzymatic cleavage). For instance, cathepsins are proteases cleaving proteins at a low pH. Cathepsins includes cathepsin A, cathepsin B, cathepsin D, cathepsin K, and cathepsin V. Bond cleavage or scission can be homolytic or heterolytic.

[0045] “Physiological pH” refers to a pH range about 4 to 8 at a temperature ranging from about 20 to 40°C, an atmospheric pressure of about 1 atm (101 kPa or 14.7 psi).

[0046] "Heteroalkenylene" is a heteroalkylene, as defined above, comprising at least one carboncarbon double bond. Unless stated otherwise specifically in the specification, a heteroalkenylene group is optionally substituted.

[0047] "Heteroalkynylene" is a heteroalkylene comprising at least one carbon-carbon triple bond. Unless stated otherwise specifically in the specification, a heteroalkynylene group is optionally substituted. "Heteroatomic" in reference to a "heteroatomic linker" refers to a linker group consisting of one or more heteroatoms. Exemplary heteroatomic linkers include single atoms selected from the group consisting of O, N, P and S, and multiple heteroatoms for example a linker having the formula -P(O-)(=O)O- or -OP(O-)(=O)O- and multimers and combinations thereof.

[0048] "Phosphate" refers to the -OP(=O)(Ra)Rb group, wherein Ra is OH, O- or ORc; and Rb is OH, O-, ORc, a thiophosphate group or a further phosphate group, wherein Rcis a counter ion (e.g., Na+and the like).

[0049] "Phosphoalkyl" refers to the -OP(=O)(Ra)Rb group, wherein Rais OH, O- or ORC; and Rb is -Oalkyl, wherein Rc is a counter ion (e.g., Na+and the like). Unless stated otherwise specifically in the specification, a phosphoalkyl group is optionally substituted. For example, in certain embodiments, the -Oalkyl moiety in a phosphoalkyl group is optionally substituted with one or more of hydroxyl, amino, sulfhydryl, phosphate, thiophosphate, phosphoalkyl, thiophosphoalkyl, phosphoalkylether, thiophosphoalkylether or -OP(=Ra)(Rb)Rc, wherein each of Ra, Rb and Rc is as defined for compounds of structure (I).

[0050] "Phosphoalkylether" refers to the -OP(=O)(Ra)Rb group, wherein Rais OH, O- or ORC; and Rb is -Oalkylether, wherein Rc is a counter ion (e.g., Na+and the like). Unless stated otherwise specifically in the specification, a phosphoalkylether group is optionally substituted. For example, in certain embodiments, the -Oalkylether moiety in a phosphoalkylether group is optionally substituted with one or more of hydroxyl, amino, sulfhydryl, phosphate, thiophosphate, phosphoalkyl, thiophosphoalkyl, phosphoalkylether, thiophosphoalkylether or -OP(=Ra)(Rb)Rc, wherein each of Ra, Rb and Rc is as defined for compounds of structure (I), (III), and (V).

[0051] "Thiophosphate" refers to the -OP(=Ra)(Rb)Rc group, wherein Ra is O or S, Rb is OH, O-, S-, ORd or SRa; and Rc is OH, SH, O-, S-, ORd, SRd, a phosphate group or a further thiophosphate group, wherein Rd is a counter ion (e.g., Na+and the like) and provided that: i) Ra is S; ii) Rb is S- or SRd; iii)Rc is SH, S- or SRd; or iv) a combination of i), ii) and / or iii).

[0052] "Thiophosphoalkyl" refers to the -OP(=Ra)(Rb)Rc group, wherein Ra is O or S, Rb is OH, O-, S-, ORd or SRd; and Rcis -Oalkyl, wherein Rd is a counter ion (e.g., Na+and the like) and provided that: i) Ra is S; ii) Rb is S- or SRa; or iii)Ra is S and Rb is S- or SRd. Unless stated otherwise specifically in the specification, a thiophosphoalkyl group is optionally substituted. For example, in certain embodiments, the -Oalkyl moiety in a thiophosphoalkyl group is optionally substituted with one or more of hydroxyl, amino, sulfhydryl, phosphate, thiophosphate, phosphoalkyl, thiophosphoalkyl, phosphoalkylether, thiophosphoalkylether or -OP(=Ra)(Rb)Rc, wherein each of Ra, Rb and Rc is as defined for compounds of structure (I), (III), and (V).

[0053] "Thiophosphoalkylether" refers to the -OP(=Ra)(Rb)Rc group, wherein Rais O or S, Rb is OH, O-, S-, ORd or SRd; and Rc is -Oalkylether, wherein Rd is a counter ion (e.g., Na+and the like) and provided that: i) Ra is S; ii) Rb is S- or SRj; or iii)Ra is S and Rb is S- or SRd. Unless stated otherwise specifically in the specification, a thiophosphoalkylether group is optionally substituted. For example, in certain embodiments, the -Oalkylether moiety in a thiophosphoalkyl group is optionally substituted with one or more of hydroxyl, amino, sulfhydryl, phosphate, thiophosphate, phosphoalkyl, thiophosphoalkyl, phosphoalkylether, thiophosphoalkylether or -OP(=Ra)(Rb)Rc, wherein each of Ra, Rb and Rcis as defined for compounds of structure (I), (III), and (V).

[0054] "Carbocyclic" refers to a stable 3- to 18-membered aromatic or non-aromatic ring comprising 3 to 18 carbon atoms. Unless stated otherwise specifically in the specification, a carbocyclic ring may be a monocyclic, bicyclic, tricyclic or tetracyclic ring system, which may include fused or bridged ring systems, and may be partially or fully saturated. Non-aromatic carbocyclyl radicals include cycloalkyl, while aromatic carbocyclyl radicals include aryl. Unless stated otherwise specifically in the specification, a carbocyclic group is optionally substituted.

[0055] "Cycloalkyl" refers to a stable non-aromatic monocyclic or polycyclic carbocyclic ring, which may include fused or bridged ring systems, having from three to fifteen carbon atoms, preferably having from three to ten carbon atoms, and which is saturated or unsaturated and attached to the rest of the molecule by a single bond. Monocyclic cycloalkyls include, for example, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl. Polycyclic cycloalkyls include, for example, adamantyl, norbomyl, decalinyl, 7,7-dimethyl- bicyclo-[2.2.1]heptanyl, and the like. Unless stated otherwise specifically in the specification, a cycloalkyl group is optionally substituted.

[0056] "Aryl" refers to a ring system comprising at least one carbocyclic aromatic ring. In some embodiments, an aryl comprises from 6 to 18 carbon atoms. The aryl ring may be a monocyclic, bicyclic, tricyclic or tetracyclic ring system, which may include fused or bridged ring systems. Aryls include, but are not limited to, aryls derived from aceanthrylene, acenaphthylene, acephenanthrylene, anthracene, azulene, benzene, chrysene, fluoranthene, fluorene, as-indacene, s-indacene, indane, indene, naphthalene, phenalene, phenanthrene, pleiadene, pyrene, and triphenylene. Unless stated otherwise specifically in the specification, an aryl group is optionally substituted. "Heterocyclic" refers to a stable 3- to 18-membered aromatic or non-aromatic ring comprising one to twelve carbon atoms and from one to six heteroatoms selected from the group consisting of nitrogen, oxygen and sulfur. Unless stated otherwise specifically in the specification, the heterocyclic ring may be a monocyclic, bicyclic, tricyclic or tetracyclic ring system, which may include fused or bridged ring systems; and the nitrogen, carbon or sulfur atoms in the heterocyclic ring may be optionally oxidized; the nitrogen atom may be optionally quatemized; and the heterocyclic ring may be partially or fully saturated. Examples of aromatic heterocyclic rings are listed below in the definition of heteroaryls (z.e., heteroaryl being a subset of heterocyclic). Examples of non-aromatic heterocyclic rings include, but are not limited to, dioxolanyl, thienyl[l,3]dithianyl, decahydroisoquinolyl, imidazolinyl, imidazolidinyl, isothiazolidinyl, isoxazolidinyl, morpholinyl, octahydroindolyl, octahydroisoindolyl, 2-oxopiperazinyl, 2-oxopiperidinyl, 2-oxopyrrolidinyl, oxazolidinyl, piperidinyl, piperazinyl, 4-piperidonyl, pyrrolidinyl, pyrazolidinyl, pyrazolopyrimidinyl, quinuclidinyl, thiazolidinyl, tetrahydrofuryl, trioxanyl, trithianyl, triazinanyl, tetrahydropyranyl, thiomorpholinyl, thiamorpholinyl, 1-oxo-thiomorpholinyl, and 1,1-dioxo-thiomorpholinyl. Unless stated otherwise specifically in the specification, a heterocyclic group is optionally substituted.

[0057] "Heteroaryl" refers to a 5- to 14-membered ring system comprising one to thirteen carbon atoms, one to six heteroatoms selected from the group consisting of nitrogen, oxygen and sulfur, and at least one aromatic ring. For purposes of certain embodiments of this disclosure, the heteroaryl radical may be a monocyclic, bicyclic, tricyclic or tetracyclic ring system, which may include fused or bridged ring systems; and the nitrogen, carbon or sulfur atoms in the heteroaryl radical may be optionally oxidized; the nitrogen atom may be optionally quatemized. Examples include, but are not limited to, azepinyl, acridinyl, benzimidazolyl, benzthiazolyl, benzindolyl, benzodioxolyl, benzofuranyl, benzooxazolyl, benzothiazolyl, benzothiadiazolyl, benzo[b][l,4]dioxepinyl, 1,4-benzodioxanyl, benzonaphthofuranyl, benzoxazolyl, benzodioxolyl, benzodioxinyl, benzopyranyl, benzopyranonyl, benzofuranyl, benzofuranonyl, benzothienyl (benzothiophenyl), benzotriazolyl, benzo[4,6]imidazo[l,2-a]pyridinyl, benzoxazolinonyl, benzimidazolthionyl, carbazolyl, cinnolinyl, dibenzofuranyl, dibenzothiophenyl, furanyl, furanonyl, isothiazolyl, imidazolyl, indazolyl, indolyl, indazolyl, isoindolyl, indolinyl, isoindolinyl, isoquinolyl, indolizinyl, isoxazolyl, naphthyridinyl, oxadiazolyl, 2-oxoazepinyl, oxazolyl, oxiranyl, 1-oxidopyridinyl, 1-oxidopyrimidinyl, 1- oxidopyrazinyl, 1-oxidopyridazinyl, 1 -phenyl- IH-pyrrolyl, phenazinyl, phenothiazinyl, phenoxazinyl, phthalazinyl, pteridinyl, pteridinonyl, purinyl, pyrrolyl, pyrazolyl, pyridinyl, pyridinonyl, pyrazinyl, pyrimidinyl, pryrimidinonyl, pyridazinyl, pyrrolyl, pyrido[2,3- d]pyrimidinonyl, quinazolinyl, quinazolinonyl, quinoxalinyl, quinoxalinonyl, quinolinyl, isoquinolinyl, tetrahydroquinolinyl, thiazolyl, thiadiazolyl, thieno[3,2-d]pyrimidin-4-onyl, thieno[2,3-d]pyrimidin-4-onyl, triazolyl, tetrazolyl, triazinyl, and thiophenyl (i.e. thienyl). Unless stated otherwise specifically in the specification, a heteroaryl group is optionally substituted.

[0058] The suffix "-ene" refers to a particular structural feature (e.g., alkyl, aryl, heteroalkyl, heteroaryl) attached to the rest of the molecule through a single bond and attached to a radical group through a single bond. In other words, the suffix "-ene" refers to a linker having the structural features of the moiety to which it is attached. The points of attachment of the "-ene" chain to the rest of the molecule and to the radical group can be through one atom of or any two atoms within the chain. For example, an arylene refers to a divalent linker comprising an aryl moiety as defined herein, and a heteroarylene refers to a divalent linker comprising a heteroaryl moiety as defined herein.

[0059] "Fused" refers to a ring system comprising at least two rings, wherein the two rings share at least one common ring atom, for example two common ring atoms. When the fused ring is a heterocyclyl ring or a heteroaryl ring, the common ring atom(s) may be carbon or nitrogen. Fused rings include bicyclic, tricyclic, tertracyclic, and the like.

[0060] The term "substituted" used herein means any of the above groups (e.g., alkyl, alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenyl ene, heteroalkynylene, alkoxy, alkylether, phosphoalkyl, phosphoalkylether, thiophosphoalkyl, thiophosphoalkylether, carbocyclic, cycloalkyl, aryl, heterocyclic and / or heteroaryl) wherein at least one hydrogen atom (e.g., 1, 2, 3 or all hydrogen atoms) is replaced by a bond to a non-hydrogen atoms such as, but not limited to: a halogen atom such as F, Cl, Br, and I; an oxygen atom in groups such as hydroxyl groups, alkoxy groups, and ester groups; a sulfur atom in groups such as thiol groups, thioalkyl groups, sulfone groups, sulfonyl groups, and sulfoxide groups; a nitrogen atom in groups such as amines, amides, alkylamines, dialkylamines, arylamines, alkylarylamines, diarylamines, N-oxides, imides, and enamines; a silicon atom in groups such as trialkylsilyl groups, dialkylarylsilyl groups, alkyldiarylsilyl groups, and triarylsilyl groups; and other heteroatoms in various other groups. "Substituted" also means any of the above groups in which one or more hydrogen atoms are replaced by a higher-order bond (e.g, a double- or triple-bond) to a heteroatom such as oxygen in oxo, carbonyl, carboxyl, and ester groups; and nitrogen in groups such as imines, oximes, hydrazones, and nitriles. For example, "substituted" includes any of the above groups in which one or more hydrogen atoms are replaced with -NRgRh, -NRgC(=O)Rh, -NRgC(=O)NRgRh, -NRgC(=O)ORh, -NRgSC>2Rh, -OC(=O)NRgRh, -ORg, -SRg, -SORg, -SChRg, -OSChRg, -SChORg, =NSO2Rg, and -SChNRgRh. "Substituted also means any of the above groups in which one or more hydrogen atoms are replaced with -C(=O)Rg, -C(=O)ORg, -C(=O)NRgRh, -CtRSChRg. -CH2 SChNRgRh. In the foregoing, Rgand Rh are the same or different and independently hydrogen, alkyl, alkoxy, alkylamino, thioalkyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl, haloalkyl, heterocyclyl, A-heterocyclyl, heterocyclylalkyl, heteroaryl, A-heteroaryl and / or heteroarylalkyl. "Substituted" further means any of the above groups in which one or more hydrogen atoms are replaced by a bond to an amino, cyano, hydroxyl, imino, nitro, oxo, thioxo, halo, alkyl, alkoxy, alkylamino, thioalkyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl, haloalkyl, heterocyclyl, / / -heterocyclyl, heterocyclylalkyl, heteroaryl, / V-heteroaryl and / or heteroarylalkyl group. In addition, each of the foregoing substituents may also be optionally substituted with one or more of the above substituents.

[0061] "Conjugation" refers to the overlap of one p-orbital with another p-orbital across an intervening sigma bond. Conjugation may occur in cyclic or acyclic compounds. A "degree of conjugation" refers to the overlap of at least one p-orbital with another p-orbital across an intervening sigma bond. For example, 1, 3-butadine has one degree of conjugation, while benzene and other aromatic compounds typically have multiple degrees of conjugation. Fluorescent and colored compounds typically comprise at least one degree of conjugation.

[0062] "Fluorescent" refers to a molecule which is capable of absorbing light of a particular frequency and emitting light of a different frequency. Fluorescence is well-known to those of ordinary skill in the art.

[0063] "Colored" refers to a molecule which absorbs light within the colored spectrum (i.e., red, yellow, blue and the like).

[0064] The term "biomolecule" refers to any of a variety of biological materials, including nucleic acids, carbohydrates, amino acids, polypeptides, glycoproteins, hormones, aptamers and mixtures thereof. More specifically, the term is intended to include, without limitation, RNA, DNA, oligonucleotides, modified or derivatized nucleotides, enzymes, receptors, prions, receptor ligands (including hormones), antibodies, antigens, and toxins, as well as bacteria, viruses, blood cells, and tissue cells. The visually detectable biomolecules of the disclosure (e.g., compounds of structure (III) having a biomolecule linked thereto) are prepared, as further described herein, by contacting a biomolecule with a compound having a reactive group that enables attachment of the biomolecule to the compound via any available atom or functional group, such as an amino, hydroxy, carboxyl, or sulfhydryl group on the biomolecule.

[0065] A "reactive group" is a moiety capable of reacting with a second reactive groups (e.g., a "complementary reactive group") to form one or more covalent bonds, for example by a displacement, oxidation, reduction, addition or cycloaddition reaction. Exemplary reactive groups are provided in Table 1, and include for example, nucleophiles, electrophiles, dienes, dienophiles, aldehyde, oxime, hydrazone, alkyne, amine, azide, acylazide, acylhalide, nitrile, nitrone, sulfhydryl, disulfide, sulfonyl halide, isothiocyanate, imidoester, activated ester, ketone, a,P-unsaturated carbonyl, alkene, maleimide, a-haloimide, epoxide, aziridine, tetrazine, tetrazole, phosphine, biotin, thiirane and the like.

[0066] "Bio-conjugation" or "bio-conjugate" and related variations refer to a chemical reaction strategy for forming a stable covalent bond between two molecules. The term "bio-conjugation" is generally used when one of the molecules is a biomolecule (e.g., an antibody), but can be used to describe forming a covalent bond with a non-biomolecule (e.g., a polymeric resin). The product or compound resulting from such a reaction strategy is a "conjugate," "bio-conjugate" or a grammatical equivalent.

[0067] The terms "visible" and "visually detectable" are used herein to refer to substances that are observable by visual inspection, without prior illumination, or chemical or enzymatic activation. Such visually detectable substances absorb and emit light in a region of the spectrum ranging from about 300 to about 900 nm. Preferably, such substances are intensely colored, preferably having a molar extinction coefficient of at least about 40,000, more preferably at least about 50,000, still more preferably at least about 60,000, yet still more preferably at least about 70,000, and most preferably at least about 80,000 M^cm’1. The compounds of the disclosure may be detected by observation with the naked eye, or with the aid of an optically based detection device, including, without limitation, absorption spectrophotometers, transmission light microscopes, digital cameras and scanners. Visually detectable substances are not limited to those which emit and / or absorb light in the visible spectrum. Substances which emit and / or absorb light in the ultraviolet (UV) region (about 10 nm to about 400 nm), infrared (IR) region (about 700 nm to about 1 mm), and substances emitting and / or absorbing in other regions of the electromagnetic spectrum are also included with the scope of "visually detectable" substances.

[0068] For purposes of embodiments of the disclosure, the term "photostable visible dye" refers to a chemical moiety that is visually detectable, as defined hereinabove, and is not significantly altered or decomposed upon exposure to light. Preferably, the photostable visible dye does not exhibit significant bleaching or decomposition after being exposed to light for at least one hour. More preferably, the visible dye is stable after exposure to light for at least 12 hours, still more preferably at least 24 hours, still yet more preferably at least one week, and most preferably at least one month. Non-limiting examples of photostable visible dyes suitable for use in the compounds and methods of the disclosure include azo dyes, thioindigo dyes, quinacridone pigments, dioxazine, phthalocyanine, perinone, diketopyrrolopyrrole, quinophthalone, and truarycarbonium.

[0069] As used herein, the term "perylene derivative" is intended to include any substituted perylene that is visually detectable. However, the term is not intended to include perylene itself. The terms "anthracene derivative", "naphthalene derivative", and "pyrene derivative" are used analogously. In some preferred embodiments, a derivative (e.g., perylene, pyrene, anthracene or naphthalene derivative) is an imide, bisimide or hydrazamimide derivative of perylene, anthracene, naphthalene, or pyrene.

[0070] The visually detectable molecules of various embodiments of the disclosure are useful for a wide variety of analytical applications, such as biochemical and biomedical applications, in which there is a need to determine the presence, location, or quantity of a particular analyte (e.g., biomolecule). In another aspect, therefore, the disclosure provides a method for visually detecting a biomolecule, comprising: (a) providing a biological system with a visually detectable biomolecule comprising the compound of structure (III) linked to a biomolecule; and (b) detecting the biomolecule by its visible properties. For purposes of the disclosure, the phrase "detecting the biomolecule by its visible properties" means that the biomolecule, without illumination or chemical or enzymatic activation, is observed with the naked eye, or with the aid of a optically based detection device, including, without limitation, absorption spectrophotometers, transmission light microscopes, digital cameras and scanners. A densitometer may be used to quantify the amount of visually detectable biomolecule present. For example, the relative quantity of the biomolecule in two samples can be determined by measuring relative optical density. If the stoichiometry of dye molecules per biomolecule is known, and the extinction coefficient of the dye molecule is known, then the absolute concentration of the biomolecule can also be determined from a measurement of optical density. As used herein, the term "biological system" is used to refer to any solution or mixture comprising one or more biomolecules in addition to the visually detectable biomolecule. Nonlimiting examples of such biological systems include cells, cell extracts, tissue samples, electrophoretic gels, assay mixtures, and hybridization reaction mixtures. “Antineoplastic” or “antineoplastic agents” refer to any molecules blocking the formation of neoplasms where the growth of the neoplasms may become cancer. Antineoplastic agents may include azacitidine, capecitabine, carmofur, cladribine, clofarabine, cytarabine, decitabine, floxuridine, fludarabine, fluorouracil, gemcitabine, mercaptopurine, nelarabine, pentostatin, tegafur, tioguanine, methotrexate, pemetrexed, raltitrexed, hydroxycarbamide, irinotecan, topotecan, daunorubicin, doxorubicin, epirubicin, idarubicin, mitoxantrone, valrubicin, etoposide, teniposide, cabazitaxel, docetaxel, paclitaxel, vinblastine, vincristine, vindesine, vinflunine, vinorelbine, bendamustine, busulfan, carmustine, chlorambucil, chlormethine, cyclophosphamide, dacarbazine, fotemustine, ifosfamide, lomustine, melphalan, streptozotocin, temozolomide, carboplatin, cisplatin, nedaplatin, oxaliplatin, altretamine, bleomycin, bortezomib, dacinomycin, estramustine, ixabepilone, mitomycin, or procarbazine. In particular embodiments, antineoplastic agents include monomethyl auristatin E (MMAE), monomethyl auristatin F (MMAF), paclitaxel, camptonthecin, doxorubicin, and PF-06380101.

[0071] “Self- immolative group” refers to a group that undergoes an electronic cascade which results in the release of the group to which it is attached. In some embodiments, the self- immolative group comprises one or more groups which can undergo 1,4-elimination, 1,6- elimination, 1,8-elimination, 1,6- cyclization elimination, 1,5-cyclization elimination, 1,3- cyclization elimination, intramolecular 5-exo-trig cyclization, and / or 6-exo-trig cyclization. In certain embodiments, the self-immolative group comprises valine (Vai) and citrulline (Cit) or valine (Vai) and alanine (Ala).

[0072] “Spacer group” refers to a linker covalently bonding between the self-immolative group and an antineoplastic agent. In one embodiment, the spacer group is para-aminobenzylcarbamate (PBA).

[0073] "Solid support" or "solid resin" refers to any solid substrate known in the art for solidphase support of molecules, for example a "microparticle" refers to any of a number of small particles useful for attachment to compounds of the disclosure, including, but not limited to, glass beads, magnetic beads, polymeric beads, nonpolymeric beads, and the like. In certain embodiments, a microparticle comprises polystyrene beads. In some embodiments, the solid support or solid resin is controlled pore glass or macroporous polystyrene.

[0074] A "solid support residue" refers to the functional group remaining attached to a molecule when the molecule is cleaved from the solid support. Solid support residues are known in the art and can be easily derived based on the structure of the solid support and the group linking the molecule thereto. A "targeting moiety" is a moiety that selectively binds or associates with a particular target, such as an analyte molecule. "Selectively" binding or associating means a targeting moiety preferentially associates or binds with the desired target relative to other targets. In some embodiments the compounds disclosed herein include linkages to targeting moieties for the purpose of selectively binding or associating the compound with an analyte of interest (i.e., the target of the targeting moiety), thus allowing detection of the analyte. Exemplary targeting moieties include, but are not limited to, antibodies, antigens, nucleic acid sequences, enzymes, proteins, cell surface receptor antagonists, and the like. In some embodiments, the targeting moiety is a moiety, such as an antibody, that selectively binds or associates with a target feature on or in a cell, for example a target feature on a cell membrane or other cellular structure, thus allowing for detection of cells of interest. Small molecules that selectively bind or associate with a desired analyte are also contemplated as targeting moieties in certain embodiments. One of skill in the art will understand other analytes, and the corresponding targeting moiety, that will be useful in various embodiments.

[0075] "Base pairing moiety" refers to a heterocyclic moiety capable of hybridizing with a complementary heterocyclic moiety via hydrogen bonds (e.g., Watson-Crick base pairing). Base pairing moieties include natural and unnatural bases. Non-limiting examples of base pairing moieties are RNA and DNA bases such adenosine, guanosine, thymidine, cytosine and uridine and analogues thereof.

[0076] Embodiments of the disclosure disclosed herein are also meant to encompass all compounds being isotopically-labelled by having one or more atoms replaced by an atom having a different atomic mass or mass number. Examples of isotopes that can be incorporated into the disclosed compounds include isotopes of hydrogen, carbon, nitrogen, oxygen, phosphorous, fluorine, chlorine, and iodine, such as2H,3H,UC,13C,14C,13N,15N,15O,17O,180,31P,32P,35S,18F,35C1,123I, and125I, respectively.

[0077] Isotopically-labeled compounds of structure (III) can generally be prepared by conventional techniques known to those skilled in the art or by processes analogous to those described below and in the following Examples using an appropriate isotopically-labeled reagent in place of the non-labeled reagent previously employed.

[0078] "Stable compound" and "stable structure" are meant to indicate a compound that is sufficiently robust to survive isolation to a useful degree of purity from a reaction mixture, and formulation into an efficacious therapeutic agent. "Optional" or "optionally" means that the subsequently described event or circumstances may or may not occur, and that the description includes instances where said event or circumstance occurs and instances in which it does not. For example, "optionally substituted alkyl" means that the alkyl group may or may not be substituted and that the description includes both substituted alkyl groups and alkyl groups having no substitution.

[0079] "Salt" includes both acid and base addition salts.

[0080] "Acid addition salt" refers to those salts which are formed with inorganic acids such as, but not limited to, hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid and the like, and organic acids such as, but not limited to, acetic acid, 2,2-dichloroacetic acid, adipic acid, alginic acid, ascorbic acid, aspartic acid, benzenesulfonic acid, benzoic acid, 4- acetamidobenzoic acid, camphoric acid, camphor- 10-sulfonic acid, capric acid, caproic acid, caprylic acid, carbonic acid, cinnamic acid, citric acid, cyclamic acid, dodecyl sulfuric acid, ethane- 1,2-disulfonic acid, ethanesulfonic acid, 2-hydroxyethanesulfonic acid, formic acid, fumaric acid, galactaric acid, gentisic acid, glucoheptonic acid, gluconic acid, glucuronic acid, glutamic acid, glutaric acid, 2-oxo-glutaric acid, glycerophosphoric acid, glycolic acid, hippuric acid, isobutyric acid, lactic acid, lactobionic acid, lauric acid, maleic acid, malic acid, malonic acid, mandelic acid, methanesulfonic acid, mucic acid, naphthalene-l,5-disulfonic acid, naphthal ene-2-sulfonic acid, 1 -hydroxy -2-naphthoic acid, nicotinic acid, oleic acid, orotic acid, oxalic acid, palmitic acid, pamoic acid, propionic acid, pyroglutamic acid, pyruvic acid, salicylic acid, 4-aminosalicylic acid, sebacic acid, stearic acid, succinic acid, tartaric acid, thiocyanic acid, p-toluenesulfonic acid, trifluoroacetic acid, undecylenic acid, and the like.

[0081] "Base addition salt" refers to those salts which are prepared from addition of an inorganic base or an organic base to the free acid. Salts derived from inorganic bases include, but are not limited to, sodium, potassium, lithium, ammonium, calcium, magnesium, iron, zinc, copper, manganese, aluminum salts and the like. Salts derived from organic bases include, but are not limited to, salts of primary, secondary, and tertiary amines, substituted amines including naturally occurring substituted amines, cyclic amines and basic ion exchange resins, such as ammonia, isopropylamine, trimethylamine, diethylamine, triethylamine, tripropylamine, diethanolamine, ethanolamine, deanol, 2-dimethylaminoethanol, 2-diethylaminoethanol, dicyclohexylamine, lysine, arginine, histidine, caffeine, procaine, hydrabamine, choline, betaine, benethamine, benzathine, ethylenediamine, glucosamine, methylglucamine, theobromine, triethanolamine, tromethamine, purines, piperazine, piperidine, N-ethylpiperidine, polyamine resins and the like. Particularly preferred organic bases are isopropylamine, diethylamine, ethanolamine, trimethylamine, dicyclohexylamine, choline and caffeine.

[0082] Crystallizations may produce a solvate of the compounds described herein. Embodiments of the present disclosure include all solvates of the described compounds. As used herein, the term "solvate" refers to an aggregate that comprises one or more molecules of a compound of the disclosure 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 disclosure may exist as a hydrate, including a monohydrate, dihydrate, hemihydrate, sesquihydrate, trihydrate, tetrahydrate and the like, as well as the corresponding solvated forms. The compounds of the disclosure may be true solvates, while in other cases the compounds of the disclosure may merely retain adventitious water or another solvent or be a mixture of water plus some adventitious solvent.

[0083] Embodiments of the compounds of the disclosure (e.g., compounds of structure I), or their salts, tautomers or solvates may contain one or more stereocenters and may thus give rise to enantiomers, diastereomers, and other stereoisomeric forms that may be defined, in terms of absolute stereochemistry, as (R)- or (S)- or, as (D)- or (L)- for amino acids. Embodiments of the present disclosure are meant to include all such possible isomers, as well as their racemic and optically pure forms. Optically active (+) and (-), (R)- and (S)-, or (D)- and (L)- isomers may be prepared using chiral synthons or chiral reagents, or resolved using conventional techniques, for example, chromatography and fractional crystallization. Conventional techniques for the preparation / isolation of individual enantiomers include chiral synthesis from a suitable optically pure precursor or resolution of the racemate (or the racemate of a salt or derivative) using, for example, chiral high pressure liquid chromatography (HPLC). When the compounds described herein contain olefinic double bonds or other centers of geometric asymmetry, and unless specified otherwise, it is intended that the compounds include both E and Z geometric isomers. Likewise, all tautomeric forms are also intended to be included.

[0084] 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 disclosure contemplates various stereoisomers and mixtures thereof and includes "enantiomers", which refers to two stereoisomers whose molecules are non-superimposable mirror images of one another. 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. Various tautomeric forms of the compounds are easily derivable by those of ordinary skill in the art.

[0085] The chemical naming protocol and structure diagrams used herein are a modified form of the I.U.P.A.C. nomenclature system, using the ACD / Name Version 9.07 software program and / or ChemDraw Ultra Version 11.0 software naming program (CambridgeSoft). Common names familiar to one of ordinary skill in the art are also used.

[0086] Methods for preparation of compounds useful as covalent linkers between biologically active moieties such as antineoplastic agents or enediyne antitumor antibiotics and targeting moieties are provided. Methods of the present disclosure allow attaching amine-containing biologically active moieties to the polymer backbone via physiologically cleavable or non- cleavable linkers. The procedures described in the present disclosure provide the ability to selectively install the physiologically cleavable and / or non-cleavable linkers. This allows for synthesizing a compound which has both physiologically cleavable and non-cleavable linkers with one or more biologically active moieties. In this regard, the biologically active moieties can be cleaved sequentially depending on physiological conditions. Further, a compound with both multiple biologically active moieties and fluorescent or colored moieties attached by physiologically cleavable and / or non-cleavable linkers can be synthesized.

[0087] Methods of the present disclosure also allow for control of the number and type of biologically active moieties that are attached to the polymer backbone and any subsequent targeting moiety, spacing between the neighboring biologically active moieties on the polymer backbone (e.g., how far or close the biologically active moieties), and spacing between the polymer backbone and the biological active moiety (e.g., the length of linkers of the polymer backbone).

[0088] The resulting compounds includes combinations of therapeutic agents, targeting moieties, and dye moieties (e.g., chromophores or fluorophores) that can be used for simultaneous targeting, treatment, and detection. The ease of coupling polymer-drug constructs to targeting agents such as antibodies, antibody fragments, proteins or other clinically interesting agents provides utility to a wide variety of interesting applications (e.g., surface chemistries, assay development, etc.).

[0089] The compounds formed by methods of the present disclosure also provide other desirable properties, including enhanced permeability and retention effects. In addition to providing necessary solubility characteristics, the chemical features of embodiments of the present compounds can be adjusted to modulate the compound’s ability to permeate diseased cells / tissues and be retained within the same. These features allow effective delivery of biologically active agents by increasing permeation and increasing efficacy by enhancing retention.

[0090] In one embodiment is provided a method for preparing polymer-drug conjugates containing both biologically active moieties and fluorescent or colored dyes, the method comprising reacting a compound of structure (I): with a compound of structure (II):

[0091] M2-NHR8

[0092] (II) wherein:

[0093] M1is, at each occurrence, independently a moiety comprising a fluorescent or colored dye;

[0094] M2is a moiety comprising a biologically active moiety or a fluorescent or colored dye;

[0095] G is, at each occurrence, independently a moiety comprising a reactive group, a group convertible into a reactive group, or protected analogue thereof, capable of forming a covalent bond with an amine group;

[0096] L1and L7are at each occurrence, independently an alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenylene, heteroalkynylene, arylene or heteroarylene linker or combinations thereof;

[0097] L2, L3, L5, and L5are, at each occurrence, independently absent or an alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenyl ene or heteroalkynylene linker;

[0098] L4is, at each occurrence, independently an alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenylene or heteroalkynylene linker;

[0099] R1and R2are each independently H, OH, SH, alkyl, alkoxy, alkylether, heteroalkyl, -OP(=Ra)(Rb)Rc, or Q;

[0100] R3is, at each occurrence, independently H, alkyl or alkoxy;

[0101] R4is, at each occurrence, independently OH, SH, O', S', ORd or SRa; R5is, at each occurrence, independently oxo, thioxo or absent;

[0102] R6and R7are, at each occurrence, independently H, OH, or halo;

[0103] R8is H or alkyl;

[0104] Ra is O or S;

[0105] Rb is OH, SH, O', S', ORa or SRa;

[0106] Re is OH, SH, O', S', ORa, OL', SRd, alkyl, alkoxy, heteroalkyl, heteroalkoxy, alkylether, alkoxyalkylether, phosphate, thiophosphate, phosphoalkyl, thiophosphoalkyl, phosphoalkylether or thiophosphoalkylether;

[0107] Rd is a counter ion;

[0108] Q is, at each occurrence, independently a moiety comprising a reactive group, or protected form thereof, capable of forming a covalent bond with a complementary reactive group Q' on a targeting moiety;

[0109] L' is, at each occurrence, independently a linker comprising a covalent bond to Q, a targeting moiety, a linker comprising a covalent bond to a targeting moiety, a linker comprising a covalent bond to a solid support, a linker comprising a covalent bond to a solid support residue, a solid support residue, a linker comprising a covalent bond to a nucleoside, or a linker comprising a covalent bond to a further compound of structure (I); m and p are, at each occurrence, independently an integer of zero or greater; w is, at each occurrence, an integer of one or greater; and n is an integer of one or greater, thereby: i) forming a bond between G of the compound of structure (I) and -NHR8of the compound of structure (II).

[0110] The various linkers and substituents (e.g., M1, R1, R2, R3, R4, R5, R6, R7, L1, L2, L3, L4, L5, L6L7, and Q) in the compound of structure (I) are optionally substituted with one more substituent. For example, in some embodiments the optional substituent is selected to optimize the water solubility or other property of the compound of structure (I). In certain embodiments, each alkyl, alkoxy, alkylether , alkoxyalkylether, phosphoalkyl, thiophosphoalkyl, phosphoalkylether and thiophosphoalkylether in the compound of structure (I) is optionally substituted with one more substituent selected from the group consisting of hydroxyl, alkoxy, alkylether , alkoxyalkylether, sulfhydryl, amino, alkylamino, carboxyl, phosphate, thiophosphate, phosphoalkyl, thiophosphoalkyl, phosphoalkylether and thiophosphoalkylether. In certain embodiments the optional substituent is -OP(=Ra)(Rb)Rc, where Ra, Rb and Rc are as defined for the compound of structure (I). In some embodiments, G is, at each occurrence, independently -C(=O)OH or -C(=O)H.

[0111] In some related embodiments, the compound of structure (I) has the following structure (IA) or (IB):

[0112] The linker L1can be used as a point of attachment of the G group to the reminder of the compound.

[0113] In some embodiments, at least one occurrence of L1comprises a linker that is non- cleavable under physiological conditions. Accordingly, in some embodiments, L1comprises an amide bond, an ester bond, a disulfide bond, a hydrazone, a phosphotriester, a diester, P- glucuronide, a double bond, a triple bond, an ether bond, a ketone, a diol, or combinations thereof.

[0114] In some embodiments, L1comprises tert-butyloxycarbonyl, paramethoxybenzyl, dialkyl or diaryldialkoxysilane, orthoester, acetal, P-thiopropionate, ketal, phosphoramidate, hydrazone, vinyl ether, imine, aconityl, trityl, polyketal, bisarylhydrazone, diazobenzene, vivinal diol, pyrophosphate diester, or valine citrulline.

[0115] In some embodiments, L1is, at each occurrence, independently a linker that is cleavable at a pH ranging from 6 to 8. For example, in some embodiments L1is a linker that is cleavable at pH 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, or 8.0.

[0116] In certain embodiments, L1is, at each occurrence, independently a linker that is cleavable at a temperature ranging from 20°C to 40°C, from 25°C to 35°C, from 30°C to 35°C, from 30°C to 37°C, from 35°C to 37°C, from 35°C to 40°C, from 32°C to 38°C. In certain embodiments, L is, at each occurrence, independently a linker that is cleavable at a temperature of about 20°C, about 21°C, about 22°C, about 23°C, about 24°C, about 25°C, about 26°C, about 27°C, about 28°C, about 29°C, about 30°C, about 31°C, about 32°C, about 33°C, about 34°C, about 35°C, about 36°C, about 37°C, about 38°C, about 39°C, or about 40°C.

[0117] In certain embodiments, L1is, at each occurrence, independently a linker that is cleavable by an enzyme. For example, in some embodiments, the enzyme is a hydrolase, an oxidoreductase or a lyase. In certain embodiments, the enzyme is an EC 4.1 (e.g., EC 4.1.1, EC 4.1.2, EC 4.1.3 or EC 4.1.99), EC 4.2, EC 4.3, EC4.4, EC 4.5, EC 4.6, or EC 4.99 enzyme.

[0118] In some embodiments, for at least one occurrence of L1, L^G has the following structure:

[0119] In some embodiments, at least one occurrence of Llais an optionally substituted 5-9 membered heteroarylene linker. In certain embodiments, Llais a substituted 5-membered heteroarylene linker. In certain embodiments, Llais a substituted 6-membered heteroarylene linker. In certain embodiments, Llais a substituted 7-membered heteroarylene linker. In certain embodiments, Llais a substituted 8-membered heteroarylene linker. In certain embodiments, Llais a substituted 9-membered heteroarylene linker. In some related embodiments, Llais substituted with oxo, alkyl (e.g., methyl, ethyl, etc.) or combinations thereof. In certain embodiments, Llais, at each occurrence, unsubstituted. In some more specific embodiments, Llais, at each occurrence independently a pyrimidine. In some more specific embodiments, Llais, at each occurrence, independently cytosine or thymine. In some embodiments, Llais, at each occurrence, independently selected from cytosine and thymine such that the compound comprises a sequence of cytosine and thymine bases capable of triplex formation with a target DNA sequence.

[0120] In some embodiments, Llahas one of the following structures:

[0121] In some embodiments, Llbis, at each occurrence, independently an optional alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenyl ene, heteroalkynylene, alkyl eneheteroary 1 enealkyl ene, alky 1 eneheterocy cly 1 enealky 1 ene, alkyl enecarb ocy cly 1 enealky 1 ene, heteroalkyl eneheteroary 1 enealky 1 ene, heteroalkyleneheterocyclylenealkylene, heteroalkylenecarbocyclylenealkylene, heteroalkyleneheteroaryleneheteroalkylene, heteroalkyleneheterocyclyleneheteroalkylene, heteroalkylenecarbocyclyleneheteroalkylene, alkyleneheteroaryleneheteroalkylene, alkyl eneheterocyclyleneheteroalkylene, alkylenecarbocyclyleneheteroalkylene, heteroarylene, heterocyclylene, carbocyclylene, alkyleneheteroarylene, alkyleneheterocyclylene, heteroarylenealkylene, alkylenecarbocyclylene, carbocyclylenealkylene, heteroalkyleneheteroarylene, heteroalkyleneheterocyclylene, heteroaryleneheteroalkylene, heteroalkylenecarbocyclylene, carbocyclyleneheteroalkylene or heteroatomic linker. In some embodiments, Llbis an optionally substituted heteroalkenylene linker.

[0122] In some more specific embodiments, Laand Lbtogether ( / .e., has one of the following structures: In some embodiments, at least one occurrence of L1comprises one or more amino acid residues. In some embodiments, the amino acid residue is valine. In certain embodiments, at least one occurrence of L1comprises one of the following structures:

[0123]

[0124] In some embodiments, at least one occurrence of L1comprises one of the following structures: In some embodiments, at least one occurrence of L4is heteroalkylene. In some embodiments, each occurrence of L4is heteroalkylene. In some embodiments, at least one occurrence of L4comprises alkylene oxide. In some more specific embodiments, the alkylene oxide of L4is ethylene oxide. In some more specific embodiments, the ethylene oxide is polyethylene oxide. In certain embodiments, L4, at each occurrence, has the following structure: wherein: z is an integer from 1 to 100; and

[0125] * indicates a bond to the adjacent phosphorous atom.

[0126] In some embodiments, z is an integer from 3 to 8. In some embodiments, z is 3. In some embodiments, z is 4. In some embodiments, z is 5. In some embodiments, z is 6. In some embodiments, z is 7. In some embodiments, z is 8.

[0127] In some other embodiments, z is an integer from 22 to 26. In some embodiments, z is 22. In some embodiments, z is 23. In some embodiments, z is 24. In some embodiments, z is 25. In some embodiments, z is 26.

[0128] In some other embodiments, z ranges from 19 to 28. In certain embodiments, the average z is 23. In some embodiments, the average z is 19, 20, 21, 22, 23, 24, 25, 26, 27, or 28.

[0129] / R5\

[0130] TO- P—L4_J —

[0131] In some embodiments, at least one occurrence of ' R4'min compounds of structure (I) comprises one of the following structures: wherein z is an integer from 1 to 100.

[0132] In some embodiments, z is an integer from 3 to 8. In some other embodiments, z is an integer from 22 to 26. In some other embodiments, z ranges from 19 to 28. In some embodiments, at each occurrence, in compounds of structure (I) comprises one of the following structures:

[0133] In some specific embodiments, comprises one of the following structures:

[0134] In some m p , p wing structure: in some other specific embodiments, comprises the following structure:

[0135] In some embodiments, the compound of structure (I) has the following structure (IC) or

[0136] (ID):

[0137] In some embodiments, L2, L3, L5, and L6are, at each occurrence, independently absent (i.e., a direct bond) or independently an alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenylene or heteroalkynylene linker. In some embodiments, L2, L3, L5, and L6are, at each occurrence, independently alkylene. In more embodiments, L2, L3, L5, and L6are, at each occurrence, independently Ci-Ce alkylene, C2-C6 alkenylene or C2-C6 alkynylene. In some more specific embodiments, the alkylene linker of L2, L3, L5, and L6is a Ci alkylene linker. In some more specific embodiments, the alkylene linker of L2, L3, L5, and L6is a C2 alkylene linker. In some more specific embodiments, the alkylene linker of L2, L3, L5, and L6is a C3 alkylene linker. In some more specific embodiments, the alkylene linker of L3and L5is a C4 alkylene linker. In some more specific embodiments, the alkylene linker of L2, L3, L5, and L6is a Cs alkylene linker. In some more specific embodiments, the alkylene linker of L2, L3, L5, and L6is a Cr> alkylene linker. In some other embodiments, at least one occurrence of L2, L3, L5, and Lsare a direct bond. In certain embodiments, at least one occurrence of L2is absent. In more specific embodiments, L2is absent at each occurrence.

[0138] In some related embodiments, the compound of structure (I) has the following structure (IE) or (IF): wherein y1, y2, y3, and y4are, at each occurrence, independently an integer from 0 to 6.

[0139] In some embodiments, y1, y2, y3, and y4are, at each occurrence, an integer 0 ( / '.<?., each of L2, L3, L5, and L6is a direct bond). In some embodiments, y1, y2, y3, and y4are, at each occurrence, an integer 1. In some embodiments, y1, y2, y3, and y4are, at each occurrence, an integer 2. In some embodiments, y1, y2, y3, and y4are, at each occurrence, an integer 3. In some embodiments, y1, y2, y3, and y4are, at each occurrence, an integer 4. In some embodiments, y1, y2, y3, and y4are, at each occurrence, an integer 5. In some embodiments, y1, y2, y3, and y4are, at each occurrence, an integer 6. In some more specific embodiments, y1, y2, y3, and y4are each 0 or 1 at each occurrence.

[0140] The linker L7can be used as a point of attachment of the M1moieties to the remainder of the compound (e.g., heteroalkylene backbone). For example, in some embodiments a synthetic precursor to the compound of structure (I) is prepared, and the M1moieties are attached to the synthetic precursor using any number of facile methods known in the art, for example methods referred to as "click chemistry." For this purpose, any reaction which is rapid and substantially irreversible can be used to attach M1to the synthetic precursor to form a compound of structure (I). Exemplary reactions include the copper catalyzed reaction of an azide and alkyne to form a triazole (Huisgen 1, 3-dipolar cycloaddition), reaction of a diene and dienophile (Diels-Alder), strain-promoted alkyne-nitrone cycloaddition, strain-promoted cycloalkyne-azide cycloaddition (Cu-free click), reaction of a strained alkene with an azide, tetrazine or tetrazole, alkene and azide [3+2] cycloaddition, alkene and tetrazine inverse-demand Diels-Alder, alkene and tetrazole photoreaction and various displacement reactions, such as displacement of a leaving group by nucleophilic attack on an electrophilic atom. Exemplary displacement reactions include reaction of an amine with: an activated ester; an N-hydroxysuccinimide ester; an isocyanate; an isothioscyanate or the like. In some embodiments the reaction to form L7may be performed in an aqueous environment.

[0141] Accordingly, in some embodiments L7is at each occurrence, independently a linker comprising a functional group capable of formation by reaction of two complementary reactive groups, for example a functional group which is the product of one of the foregoing "click" reactions. In various embodiments, for at least one occurrence of L7, the functional group can be formed by reaction of an oxime, hydrazone, alkyne, amine, azide, acylazide, acylhalide, nitrile, nitrone, sulfhydryl, disulfide, sulfonyl halide, isothiocyanate, imidoester, activated ester (e.g., N- hydroxysuccinimide ester), ketone, a,[3-unsaturated carbonyl, alkene, maleimide, a-haloimide, epoxide, aziridine, tetrazine, tetrazole, phosphine, biotin or thiirane functional group with a complementary reactive group, for example, via a reaction of an amine with an N- hydroxysuccinimide ester or isothiocyanate.

[0142] In other embodiments, for at least one occurrence of L7, the functional group can be formed by reaction of an alkyne and an azide. In other embodiments, for at least one occurrence of L7, the functional group can be formed by reaction of an amine (e.g., primary amine) and an N-hydroxysuccinimide ester or isothiocyanate.

[0143] In more embodiments, for at least one occurrence of L7, the functional group comprises an alkene, ester, amide, thioester, disulfide, carbocyclic, heterocyclic or heteroaryl group. In more embodiments, for at least one occurrence of L7, the functional group comprises an alkene, ester, amide, thioester, thiourea, disulfide, carbocyclic, heterocyclic or heteroaryl group. In other embodiments, the functional group comprises an amide or thiourea. In some more specific embodiments, for at least one occurrence of L7, L7is a linker comprising a triazolyl functional group. In some related embodiments, L7, at each occurrence, independently comprises a triazolyl functional group. While in other embodiments, for at least one occurrence of L7is a linker comprising an amide or thiourea functional group.

[0144] In some embodiments, at least one occurrence of L7is alkylene or heteroalkylene. In more specific embodiments, at least one occurrence of L7comprises one of the following structures:

[0145]

[0146] In more specific embodiments, at least one occurrence of L7comprises one of the following structures:

[0147] In some more specific embodiments, the linker L7has the following structure:

[0148] In still other embodiments, for at least one occurrence of L7, I7-M1has one of the following structures: wherein L7aand L7bare each independently optional linkers.

[0149] In some embodiments, L7aor L7b, or both, is absent. In other embodiments, L7aor L7b, or both, is present.

[0150] In some embodiments L7aand L7b, when present, are each independently alkylene or heteroalkylene. For example, in some embodiments L7aand L7b, when present, independently have one of the following structures:

[0151] In some embodiments, ML-L7has one of the following structures: wherein a, b, c, and d are each independently an integer ranging from 1-6. In some embodiments, a, b, c, and d are each independently an integer 1. In some embodiments, a, b, c, and d are each independently an integer 2. In some embodiments, a, b, c, and d are each independently an integer 3. In some embodiments, a, b, c, and d are each independently an integer 4. In some embodiments, a, b, c, and d are each independently an integer 5. In some embodiments, a, b, c, and d are each independently an integer 6.

[0152] In some more specific embodiments, at least one occurrence of L7comprises one of the following structures: In some embodiments, at least one occurrence of L7comprises one of the following structures:

[0153] In some embodiments, at least one occurrence of R3is H. In some embodiments, at least one occurrence of R1is alkyl. In some embodiments, at least one occurrence of R1is alkoxy. In certain embodiments, each occurrence of R1is H.

[0154] In some embodiments, at least one occurrence of R4is OH. In some embodiments, at least one occurrence of R4is SH. In some embodiments, at least one occurrence of R4is O'. In some embodiments, at least one occurrence of R4is S'. In certain embodiments, each occurrence of R4is O'.

[0155] In some embodiments, at least one occurrence of R5is oxo (=0). In some embodiments, at least one occurrence of R5is thioxo (=S). In certain embodiments, each occurrence of R5is oxo (=0).

[0156] In some embodiments, R1and R2are each independently OH or -OP(=Ra)(Rb)Rc. In some different embodiments, R1or R2is OH or -OP(=Ra)(Rb)Rc, and the other of R2or R3is Q or a linker comprising a covalent bond to Q.

[0157] In still more different embodiments of any of the foregoing compounds of structure (I), R2and R3are each independently -OP(=Ra)(Rb)Rc. In some of these embodiments, Rc is OL1.

[0158] In other embodiments, R1and R2are each independently -0P(=R3)(Rb)0L', and L' is an alkylene or heteroalkylene linker to: Q, a targeting moiety, an analyte (e.g., analyte molecule), a solid support, a solid support residue, a nucleoside or a further compound of structure (I).

[0159] The linker L' can be any linker suitable for attaching Q, a targeting moiety, an analyte (e.g., analyte molecule), a solid support, a solid support residue, a nucleoside or a further compound of structure (I) to the compound of structure (I). Advantageously certain embodiments include use of L' moieties selected to increase or optimize water solubility of the compound. In certain embodiments, L' is a heteroalkylene moiety. In some other certain embodiments, L' comprises an alkylene oxide or phosphodiester moiety, or combinations thereof.

[0160] In certain embodiments, L' has the following structure: wherein: m" and n" are independently an integer from 1 to 10;

[0161] Reis H, an electron pair or a counter ion;

[0162] L" is Reor a direct bond or linkage to: Q, a targeting moiety, an analyte (e.g., analyte molecule), a solid support, a solid support residue, a nucleoside or a further compound of structure (I).

[0163] In some embodiments, m" is an integer from 4 to 10, for example 4, 6 or 10. In other embodiments n" is an integer from 3 to 6, for example 3, 4, 5 or 6. In some embodiments, n" is an integer from 18-28, for example, from 21-23.

[0164] In some other embodiments, L" is an alkylene, alkyleneheterocyclylene, alkyleneheterocyclylenealkylene, alkylenecyclylene, alkylenecyclylenealkylene, heteroalkylene, heteroalkyleneheterocyclylene, heteroalkyl eneheterocyclyleneheteroalkylene, heteroalkylenecyclylene, or heteroalkylenecycleneheteroalkylene moiety. In some other certain embodiments, L" comprises an alkylene oxide, phosphodiester moiety, sulfhydryl, disulfide or maleimide moiety or combinations thereof.

[0165] In certain of the foregoing embodiments, the targeting moiety is an antibody or cell surface receptor antagonist. In some more specific embodiments, the antibody or cell surface receptor antagonist is an epidermal growth factor receptor (EGFR) inhibitor, a hepatocyte growth factor receptor (HGFR) inhibitor, an insulin-like growth factor receptor (IGFR) inhibitor, a folate, or a MET inhibitor. In other embodiments, the targeting moiety is a monoclonal antibody. For instance, in some embodiments, the monoclonal antibody is Abciximab, Adalimumab, Alemtuzumab, Alirocumab, Avibactam, Basiliximab, Benralizumab, Bezlotoxumab, Blinatumomab, Brodalumab, Burosumab, Canakinumab, Caplacizumab, Certolizumab pegol, Daclizumab, Denosumab, Dupilumab, Eculizumab, Emicizumab, Erenumab, Evolocumab, Fremanezumab, Galcanezumab, Golimumab, Guselkumab, Ibalizumab, Idarucizumab, Infliximab, Itolizumab, Ixekizumab, Lanadelumab, Lokivetmab, Mepolizumab, Natalizumab, Obiltoxaximab, Ocrelizumab, Omalizumab, Palivizumab, Ranibizumab, Raxibacumab, Reslizumab, Rmab, Rovelizumab, Ruplizumab, Sarilumab, Secukinumab, Tildrakizumab, Thiomab, Tocilizumab, Ustekinumab, Vedolizumab, Abrilumab, Actoxumab, Aducanumab, Afasevikumab, Afelimomab, Anifrolumab, Anrukinzumab (IMA-638), Aselizumab, Atorolimumab, Bapineuzumab, BCD-100, Bertilimumab, Besilesomab, Biciromab, Bimagrumab, Bimekizumab, Birtamimab, Bleselumab, Blosozumab, Bococizumab, Brazikumab, Briakinumab, Brolucizumab, Carlumab, Carotuximab, Cedelizumab, Clazakizumab, Clenoliximab, Concizumab, Cosfroviximab, CR6261, Crenezumab, Crizanlizumab, Crotedumab, Depatuxizumab, mafodotin, Derlotuximab biotin, Dezamizumab, Diridavumab, Domagrozumab, Dusigitumab, Ecromeximab, Edobacomab, Efalizumab, Efungumab, Eldelumab, Elezanumab, Enokizumab, Eptinezumab, Erlizumab, Etrolizumab, Evinacumab, Exbivirumab, Fanolesomab, Faralimomab, Faricimab, Fasinumab, Felvizumab, Fezakinumab, Flanvotumab, Fletikumab, Flotetuzumab, Fontolizumab, Foravirumab, Frovocimab, Fulranumab, Gantenerumab, Gavilimomab, Gevokizumab, Gimsilumab, Gomiliximab, Gosuranemab, lanalumab, Inclacumab, Inolimomab, lomab-B, Keliximab, Lampalizumab, Landogrozumab, Larcaviximab, Lebrikizumab, Lenvervimab, Lerdelimumab, Letolizumab, Libivirumab, Ligelizumab, Lodelcizumab, Lulizumab pegol, Marstacimab, Mavrilimumab, Metelimumab, Mirikizumab, Motavizumab, Muromonab CD3, Nebacumab, Nemolizumab, NEODOOl, Nirsevimab, Odulimomab, Olendalizumab, Olokizumab, OMS721, Opicinumab, Orticumab, Otelixizumab, Otilimab, Oxelumab, Ozanezumab, Ozoralizumab, Pagibaximab, Panobacumab, Pascolizumab, Pateclizumab, PDR001, Perakizumab, Pexelizumab, Placulumab, Plozalizumab, Ponezumab, Porgaviximab, Prasinezumab, Priliximab, PRO 140, Quilizumab, Rafivirumab, Ralpancizumab, Ranevetmab, Ravagalimab, Ravulizumab, Refanezumab, Regavirumab, Relatlimab, Rinucumab, Risankizumab, Roledumab, Romosozumab, Rontalizumab, SA237, Satralizumab, Sevirumab, SHP647, Sifalimumab, Simtuzumab, Siplizumab, Sirukumab, Solanezumab, Sonepcizumab, Spartalizumab, Stamulumab, Sulesomab, Suptavumab, Sutimlimab, Suvizumab, Suvratoxumab, Tadocizumab, Talizumab, Tamtuvetmab, Tanezumab, Tefibazumab, Telimomab aritox, Teneliximab, Teplizumab, Teprotumumab, Tezepelumab, Tibulizumab, Toralizumab, Tralokinumab, Trevogrumab, Tuvirumab, Ulocuplumab, Urtoxazumab, Varisacumab, Vepalimomab, Vesencumab, Visilizumab, Vobarilizumab, Zolimomab aritox, trastuzumab, gemtuzumab, brentuximab, vorsetuzumab, lorvotuzumab, cantuzumab, bivatuzumabor inotuzumab, or vadastuximab.

[0166] In some embodiments the analyte molecule is a nucleic acid, amino acid or a polymer thereof. In other embodiments, the analyte molecule is an enzyme, receptor, receptor ligand, antibody, glycoprotein, aptamer or prion.

[0167] In some embodiments, the solid support is a polymeric bead or nonpolymeric bead.

[0168] In other more specific embodiments of any of the foregoing compounds of structure (I), R1or R2has one of the following structures:

[0169]

[0170] Certain embodiments of compounds of structure (I) can be prepared according to solidphase synthetic methods analogous to those known in the art for preparation of oligonucleotides. Accordingly, in some embodiments, L' is a linkage to a solid support, a solid support residue or a nucleoside. Solid supports comprising an activated deoxythymidine (dT) group are readily available, and in some embodiments can be employed as starting material for preparation of compounds of structure (I) or (II). Accordingly, in some embodiments R1or R2has the following structure:

[0171] One of skill in the art will understand that the dT group depicted above is included for ease of synthesis and economic efficiencies only, and is not required. Other solid supports can be used and would result in a different nucleoside or solid support residue being present on L', or the nucleoside or solid support residue can be removed or modified post synthesis.

[0172] In some embodiments, the analyte molecule is a nucleic acid, amino acid or a polymer thereof In some embodiments, the analyte molecule is an enzyme, receptor, receptor ligand, antibody, glycoprotein, aptamer or prion. In some embodiments, the targeting moiety is an antibody or cell surface receptor antagonist. In further some embodiments, the solid support is a polymeric bead or non-polymeric bead.

[0173] In still other embodiments, Q is, at each occurrence, independently a moiety comprising a reactive group capable of forming a covalent bond with an analyte molecule or a solid support. In other embodiments, Q is, at each occurrence, independently a moiety comprising a reactive group capable of forming a covalent bond with a complementary reactive group Q'. For example, in some embodiments, Q' is present on a further compound of structure (I) (e.g., in the R2or R3position), and Q and Q' comprise complementary reactive groups such that reaction of the compound of structure (I) and the further compound of structure (I) results in covalently bound dimer of the compound of structure (I). Multimer compounds of structure (I) can also be prepared in an analogous manner and are included within the scope of embodiments of the invention.

[0174] The type of Q group and connectivity of the Q group to the remainder of the compound of structure (I) is not limited, provided that Q comprises a moiety having appropriate reactivity for forming the desired bond.

[0175] In certain embodiments, Q is a moiety which is not susceptible to hydrolysis under aqueous conditions, but is sufficiently reactive to form a bond with a corresponding group on an analyte molecule or solid support (e.g., an amine, azide or alkyne).

[0176] Certain embodiments of compounds of structure (I) comprise Q groups commonly employed in the field of bioconjugation. For example, in some embodiments, Q comprises a nucleophilic reactive group, an electrophilic reactive group or a cycloaddition reactive group. In some more specific embodiments, Q comprises a sulfhydryl, disulfide, activated ester, isothiocyanate, azide, alkyne, alkene, diene, dienophile, acid halide, sulfonyl halide, phosphine, oc-haloamide, biotin, amino or maleimide functional group. In some embodiments, the activated ester is an N-succinimide ester, imidoester or polyfluorophenyl ester. In other embodiments, the alkyne is an alkyl azide or acyl azide.

[0177] The Q groups can be conveniently provided in protected form to increase storage stability or other desired properties, and then the protecting group removed at the appropriate time for conjugation with, for example, a targeting moiety or analyte. Accordingly, Q groups include “protected forms” of a reactive group, including any of the reactive groups described above and in the Table 1 below. A “protected form” of Q refers to a moiety having lower reactivity under predetermined reaction conditions relative to Q, but which can be converted to Q under conditions, which preferably do not degrade or react with other portions of the compound of structure (I) or (II). One of skill in the art can derive appropriate protected forms of Q based on the particular Q and desired end use and storage conditions. For example, when Q is SH, a protected form of Q includes a disulfide, which can be reduced to reveal the SH moiety using commonly known techniques and reagents.

[0178] Exemplary Q moieties are provided in Table I below.

[0179] Table 1. Exemplary Q Moieties Structure Class

[0180] It should be noted that in some embodiments, wherein Q is SH, the SH moiety will tend to form disulfide bonds with another sulfhydryl group, for example on another compound of structure (I). Accordingly, some embodiments include compounds of structure (I), which are in the form of disulfide dimers, the disulfide bond being derived from SH Q groups. In other embodiments, the Q moiety is conveniently masked (e.g., protected) as a disulfide moiety, which can later be reduced to provide an activated Q moiety for binding to a desired analyte molecule or targeting moiety. For example, the Q moiety may be masked as a disulfide having the following structure: wherein R is an optionally substituted alkyl group. For example, in some embodiments, Q is provided as a disulfide moiety having the following structure: where n’ is an integer from 1 to 10.

[0181] In some embodiments, the at least one fluorescent or colored moiety M1is a fluorescent moiety. In some embodiments, M1, at each occurrence, independently comprises two or more aryl or heteroaryl rings, or combinations thereof, for example three or more or four or more aryl or heteroaryl rings, or combinations thereof, or even five or more aryl or heteroaryl rings, or combinations thereof. In some embodiments, M1, at each occurrence, independently comprises six aryl or heteroaryl rings, or combinations thereof. In further embodiments, the rings are fused. For example, in some embodiments, M1, at each occurrence, independently comprises two or more fused rings, three or more fused rings, four or more fused rings, five or more fused rings, or even six or more fused rings. In some more specific embodiments, M1, at each occurrence, independently comprises a fused-multi cyclic aryl moiety comprising at least two fused rings.

[0182] In certain specific embodiments, M1is, at each occurrence, independently selected from the group consisting of a dimethylaminostilbene, quinacridone, fluorophenyl-dimethyl-BODIPY, bis-fluorophenyl-BODIPY, acridine, terrylene, sexiphenyl, porphyrin, benzopyrene, (fluorophenyl-dimethyl-difluorobora-diaza-indacene)phenyl, ( / i / .s-fluorophenyl-difluorobora- diaza-indacene)phenyl, quaterphenyl, bi-benzothiazole, ter-benzothiazole, bi-naphthyl, bi- anthracyl, squaraine, squarylium, 9,10-ethynylanthracene, and ter-naphthyl moiety.

[0183] In some embodiments, M1is, at each occurrence, independently selected from the group consisting of p-terphenyl, perylene, azobenzene, phenazine, phenanthroline, acridine, thioxanthrene, chrysene, rubrene, coronene, cyanine, perylene imide, perylene amide, and derivatives thereof. In some embodiments, M1is, at each occurrence, independently selected from the group consisting of a coumarin dye, resorufin dye, dipyrrometheneboron difluoride dye, ruthenium bipyridyl dye, thiazole orange dye, polymethine, and N-aryl-l,8-naphthalimide dye. In certain embodiments, M1, M2, or M3are, at each occurrence, independently selected from the group consisting of a coumarin dye, boron-dipyrromethene, rhodamine, cyanine, pyrene, perylene, perylene monoimide, 6-FAM, 5-FAM, 6-FITC, 5-FITC, and derivatives thereof.

[0184] In some other embodiments, M1, at each occurrence, independently has one of the following structures:

[0185]

[0186] In certain embodiments, M1, at each occurrence, independently has one of the following structures:

[0187]

[0188] In some more specific embodiments, at least one occurrence of M1has the following structure: In some more specific embodiments, each occurrence of M1has the following structure:

[0189] In some more specific embodiments, at least one occurrence of L7M1has the following structure: In some more specific embodiments, each occurrence of-L7-M' has the following structure:

[0190] The fluorescence intensity or efficacy toward treating diseases can be turned by selected different values of m, n, p, and w.

[0191] The value for m has the ability to control the spacing between neighboring M1or M2. In some embodiments, m is an integer of zero or greater. In certain embodiments, m is an integer from 0 to 10. In some embodiments, m is 0. In some embodiments, m is 1. In some embodiments, m is 2. In some embodiments, m is 3. In some embodiments, m is 4. In some embodiments, m is 5. In some embodiments, m is 6. In some embodiments, m is 7. In some embodiments, m is 8. In some embodiments, m is 9. In some embodiments, m is 10. In some more specific embodiments, m is 1 or 2.

[0192] The fluorescence intensity may be tuned by number of fluorescent dye moieties attached to the polymeric backbone. The value for p has the ability to control the brightness of compounds. In some embodiments, p is, at each occurrence, an integer of zero or greater. In some more specific embodiments, p is from 0 to 10. In some embodiments, p is from 0 to 5. For example, in some embodiments, p is 0. In some embodiments, p is 1. In some embodiments, p is 2. In some embodiments, p is 3. In some embodiments, p is 4. In some embodiments, p is 5.

[0193] The fluorescence or efficacy toward treating diseases may also be tuned by selection of values for w. In some embodiments, w is an integer of one or greater. In certain embodiments, w is an integer from 1 to 100. In other embodiments, w is an integer from 1 to 20. In other embodiments, w is an integer from 1 to 10. In some embodiments, w is 1, 3, 5, 7, or 10. In some embodiments, w is 1. In some embodiments, w is 2. In some embodiments, w is 3. In some embodiments, w is 4. In some embodiments, w is 5. In some embodiments, w is 6. In some embodiments, w is 7. In some embodiments, w is 8. In some embodiments, w is 9. In some embodiments, w is 10.

[0194] The fluorescence intensity or the efficacy toward treating diseases can also be tuned by selection of different values of n. In some embodiments, n is an integer of one or greater. In certain embodiments, n is an integer from 1 to 100. In some embodiments, n is an integer from 1 to 20. In other embodiments, n is an integer from 1 to 10. In some embodiments, n is 1. In some embodiments, n is 2. In some embodiments, n is 3. In some embodiments, n is 4. In some embodiments, n is 5. In some embodiments, n is 6. In some embodiments, n is 7. In some embodiments, n is 8. In some embodiments, n is 9. In some embodiments, n is 10.

[0195] In some specific embodiments, m is 6, p is 1, w is 1, and n is 1. In some specific embodiments, m is 6, p is 1, w is 2, and n is 1.

[0196] In some embodiments, M2is a biologically active moiety. In some embodiments, M2is an antineoplastic agent. In some embodiments, the antineoplastic agent M2is, at each occurrence, independently selected from the group consisting of paclitaxel, camptonthecin, doxorubicin, monomethyl auristatin E (MMAE), Val-Cit-PAB-MMAE, and monomethyl auristatin F. In certain embodiments, M2has one of the following structures:

[0197]

[0198] In certain embodiments, the antineoplastic agent M2is monomethyl auristatin E. In some more specific embodiments, the antineoplastic agent M2has the following structure:

[0199] In some embodiments, M2is an antitumor antibiotic. In some embodiments, the antitumor antibiotic M2is selected from the group consisting of peplomycin sulfate, pirarubicin hydrochloride, zinostatin stimalamer, idarubicin hydrochloride, mitomycin C, bleomycin hydrochloride, doxorubicin hydrochloride, daunorubicin hydrochloride, and epirubicin hydrochloride

[0200] In some embodiments, M2is an enediyne antitumor antibiotic. In some embodiments, the enediyne antitumor antibiotic M2is calicheamicin or more specifically calicheamicin yl.

[0201] In some embodiments, M2has one of the following structures:

[0202]

[0203] In some embodiments, M2is a fluorescent or colored dye as described herein with respect to M1. In some specific embodiments, the compound of structure (I) is a compound selected from Table 2.

[0204] Table 2. Exemplary Compounds of Structure (I)

[0205]

[0206] In Table 2, FAM represents

[0207] In some embodiments, compounds of the present disclosure that are formed by reacting compounds of structure (I) with compounds of structure (II) has the following structure (III): wherein:

[0208] M1is, at each occurrence, independently a moiety comprising a fluorescent or colored dye;

[0209] M2is, at each occurrence, independently a moiety comprising a biologically active moiety or a fluorescent or colored dye, provided at least one occurrence of M2is a biologically active moiety;

[0210] L1and L7are at each occurrence, independently absent or an alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenylene, heteroalkynylene, arylene or heteroarylene linker or combinations thereof;

[0211] L2, L3, L5, and L6are, at each occurrence, independently absent or an alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenyl ene or heteroalkynylene linker;

[0212] L4is, at each occurrence, independently an alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenylene or heteroalkynylene linker;

[0213] R1and R2are each independently H, OH, SH, alkyl, alkoxy, alkylether, heteroalkyl, -OP(=Ra)(Rb)Rc, or Q;

[0214] R3is, at each occurrence, independently H, alkyl or alkoxy;

[0215] R4is, at each occurrence, independently OH, SH, O', S', ORa or SRa;

[0216] R5is, at each occurrence, independently oxo, thioxo or absent;

[0217] R5and R7are, at each occurrence, independently H, OH, or halo; Ra is O or S;

[0218] Rb is OH, SH, O', S', ORd or SRa;

[0219] Rc is OH, SH, O', S', ORd, OL', SRd, alkyl, alkoxy, heteroalkyl, heteroalkoxy, alkylether, alkoxyalkylether, phosphate, thiophosphate, phosphoalkyl, thiophosphoalkyl, phosphoalkylether or thiophosphoalkylether;

[0220] Rd is a counter ion;

[0221] Q is, at each occurrence, independently a moiety comprising a reactive group, or protected form thereof, capable of forming a covalent bond with a complementary reactive group Q' on a targeting moiety;

[0222] L' is, at each occurrence, independently a linker comprising a covalent bond to Q, a targeting moiety, a linker comprising a covalent bond to a targeting moiety, a linker comprising a covalent bond to a solid support, a linker comprising a covalent bond to a solid support residue, a solid support residue, a linker comprising a covalent bond to a nucleoside, or a linker comprising a covalent bond to a further compound of structure (I); m and p are, at each occurrence, independently an integer of zero or greater; w is, at each occurrence, independently an integer of one or greater; and n is an integer of one or greater.

[0223] In compounds of structure (III), M1, M2, R1, R2, R3, R4, R5, R6, R7, L2, L3, L4, L5, L6, L7, m, n, p, and w are defined in any one of the foregoing embodiments. The bioactive moiety M2is covalently linked to the polymer chain via L1. In compounds of structure (III), in some embodiments, M2is the same. In other embodiments, each M2is different. In still more embodiments, one or more M2is the same and one or more M2is different.

[0224] In some embodiments, at least one occurrence of L1comprises one of the following structures:

[0225] In some embodiments, at least one occurrence of L1comprises one of the following structures:

[0226]

[0227] 5 In some embodiments, at least one occurrence of L1comprises one of the following structures:

[0228]

[0229] In some embodiments, in instances where G is -C(=O)OH, the resulting compound of structure (III) has the following structure (IIIA) wherein R8and L1are defined in any one of the foregoing embodiments. In some embodiments, at least one occurrence of L4is heteroalkylene. In some embodiments, each occurrence of L4is heteroalkylene. In some embodiments, at least one occurrence of L4comprises alkylene oxide. In some more specific embodiments, the alkylene oxide of L4is ethylene oxide. In some more specific embodiments, the ethylene oxide is polyethylene oxide. In certain embodiments, L4, at each occurrence, has the following structure: wherein: z is an integer from 1 to 100; and

[0230] * indicates a bond to the adjacent phosphorous atom.

[0231] In some embodiments, the compound of structure (III) has the following structure (IIIB):

[0232] In some embodiments, L2, L3, L5, and L6are, at each occurrence, independently absent (i.e., a direct bond) or independently an alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenylene or heteroalkynylene linker. In some embodiments, L2, L3, L5, and L6are, at each occurrence, independently alkylene. In more embodiments, L2, L3, L5, and L6are, at each occurrence, independently Ci-Ce alkylene, C2-C6 alkenylene or C2-C6 alkynylene. In some more specific embodiments, the alkylene linker of L2, L3, L5, and L6is a Ci alkylene linker. In some more specific embodiments, the alkylene linker of L2, L3, L5, and L6is a C2 alkylene linker. In some more specific embodiments, the alkylene linker of L2, L3, L5, and L6is a C ; alkylene linker. In some more specific embodiments, the alkylene linker of L3and L5is a C4 alkylene linker. In some more specific embodiments, the alkylene linker of L2, L3, L5, and L6is a Cs alkylene linker. In some more specific embodiments, the alkylene linker of L2, L3, L5, and L6is a Cr> alkylene linker. In some other embodiments, at least one occurrence of L2, L3, L5, and L6are a direct bond. In certain embodiments, at least one occurrence of L2is absent. In more specific embodiments, L2is absent at each occurrence.

[0233] In some related embodiments, the compound of structure (IIII) has the following structure (IIIC): wherein y1, y2, y3, and y4are, at each occurrence, independently an integer from 0 to 6.

[0234] In some embodiments, y1, y2, y3, and y4are, at each occurrence, an integer 0 (z.e., each of L2, L3, L5, and L6is a direct bond). In some embodiments, y1, y2, y3, and y4are, at each occurrence, an integer 1. In some embodiments, y1, y2, y3, and y4are, at each occurrence, an integer 2. In some embodiments, y1, y2, y3, and y4are, at each occurrence, an integer 3. In some embodiments, y1, y2, y3, and y4are, at each occurrence, an integer 4. In some embodiments, y1, y2, y3, and y4are, at each occurrence, an integer 5. In some embodiments, y1, y2, y3, and y4are, at each occurrence, an integer 6. In some more specific embodiments, y1, y2, y3, and y4are each 0 or 1 at each occurrence.

[0235] In some specific embodiments, the compound of structure (III) is a compound selected from Table 3. The compounds in Table 3 are prepared according to the procedures set forth in the Examples.

[0236] Table 3. Exemplary Compounds of Structure (III)

[0237]

[0238]

[0239]

[0240]

[0241]

[0242]

[0243] In Table 3, FAM represents

[0244] The following Reaction Schemes illustrate exemplary methods of making compounds comprising one or more biologically active moieties and one or more fluorescent or colored moi eties (e.g., compound of structure (III)) by reacting a compound of structure (I) with a compound of structure (II)).

[0245] Reaction Scheme I illustrates direct reaction of G with an amine-containing compound of structure (II) to form compounds of structure (III) in instances where G is a reactive group.

[0246] Reaction Scheme I Reaction Scheme II

[0247] Reaction Scheme II illustrates reaction of G with an amine-containing compound of structure (II) to form compounds of structure (IIIA) in instances where G is a group convertible into a reactive group.

[0248] In instances where G is carboxylic acid, the reaction of compound of structure (IA) and the compound of structure (II) is performed in the presence of an activating agent. The activating agent converts carboxylic acid into a reactive group such as an activated ester or an anhydride In some embodiments, the carboxylic acid is converted into an activated ester, and compounds of structure (I) is reacted with an activating agent to produce compounds of structure (IA’) comprising the activated ester. In some embodiments, the activating agent comprises a guanidinium reagent, a uronium reagent, preferably 2-(H-benzotriazol-l-yl)-l, 1,3,3- tetramethyluronium hexafluorophosphate (HBTU), O-(benzotriazol-l-yl)-N,N,N',N'- tetramethyluronium tetrafluoroborate (TBTU) or 2-(lH-7-azabenzotriazol-l-yl)-l, 1,3,3- tetramethyluronium hexafluorophosphate (HATU), a benzotri azole reagent, preferably 1- hydroxybenzotriazole reagent (HOBt), an immonium reagent, a carbodiimide reagent, preferably N,N'-dicyclohexyl carbodiimide (DCC) or diisopropyl carbodiimide (DIPCDI), an imidazolium reagent, an organophosphorous reagent, an acidic halogenating reagent, a phosphonium reagent, preferably benzotriazol-l-yl-oxy-tris(dimethylamino)phosphonium hexafluorophosphate (BOP); also known as Castros reagent) or benzotriazol- 1-yl-oxytripyrrolidinophosphonium hexafluorophosphate (PyBOP), a morpholine reagent, preferably N-methylmorpholine (NMM), a chloroformate reagent and / or a combination thereof. In certain embodiments, the coupling agent is HBTU. The activated ester then reacts the amino group in compound of structure (II) to form a compound of structure (IIIA). The bioactive moiety M2thus is covalently linked to the polymer chain via the reaction of the activated ester with amine.

[0249] In compounds of structure (IA’), R9a leaving group of an activated ester. In some embodiments, R9has one of the following structures:

[0250] In some embodiments, the reaction of compound of structure (I) and compound of structure (II) may be carried out in a solution comprising an organic solvent and an activating agent. In some embodiments, the reaction may be carried out under a basic condition.

[0251] In some embodiments, the organic solvent may one or more selected from the group consisting of dimethylsulfoxide (DMSO), N-methylformamide (NMP), N-methylpyrrolidone, dimethylacetamide, dimethylformamide (DMF), di chloromethane, di chloroethane, and chloroform. In certain embodiments, the solvent is DMF.

[0252] In some embodiments, the base may be one or more selected from the group consisting of diisopropylethylamine (DIPEA), tri ethyl amine, piperidine, pyrrolidine, pyridine, N- methylmorpholin (NMM), and collidine. In certain embodiments, the base is DIPEA.

[0253] In some more specific embodiments, the coupling of the compound of structure (I) and the compound of structure (II) is carried out in the presence of HBTU in DMF.

[0254] The compounds of structure (I) may be prepared by DNA synthesis methodology. Monomers (e.g., phosphoramidite monomers) can be purchased commercially (e.g., from ChemGenes Corporation, Wilmington Mass.) or synthesized using methods known in the art (see, e.g., U.S. Publication No. 2019 / 0136065, which is hereby incorporated by reference). Introduction of desired moieties can be accomplished during the DNA synthesis steps by including the desired moiety as a portion of the monomer (see, e.g., L and M of the Representative DNA Synthesis Cycle, below). An exemplary DNA synthesis scheme is shown below.

[0255] A REPRESENTATIVE DNA SYNTHESIS CYCLE

[0256] Oligomerization is initiated, typically, through the removal of a protecting group (e.g. a dimethoxytrityl group, DMTr) to reveal a free -OH (hydroxyl) group (Step 1, DETRIT YLATION). In a subsequent coupling step, a phosphoramidite monomer is introduced that reacts with the free OH group making a new covalent bond to phosphorus, with concomitant loss of the diisopropyl amine group (Step 2, COUPLING). The resultant, phosphite triester is oxidized (e.g. with b and pyridine) to the more stable phosphate ester (Step 3, OXIDATION) and a capping step renders unreactive any remaining free OH groups (Step 4, CAPPING). The new product, phosphate oligomer, contains a DMTr protected OH group that can be deprotected to reinitiate the synthetic cycle so another phosphoramidite monomer can be appended to the oligomer.

[0257] Customization occurs at step 2 through the choice of phosphoramidite monomer. The nature of L (i.e., a linker group) and M (i.e., a fluorescent or colored dye) in the scheme above are selected such that a desired compound of structure (I) is synthesized. M can be optionally absent to incorporate desired spacing between M moieties. A person of ordinary skill in the art can select multiple monomer types to arrive at compounds of the disclosure containing multiple therapeutic agents and / or other moieties (e.g., fluorophores or chromophores) with concurrent variability in linker groups.

[0258] In some embodiments, compounds of structure (I) may be prepared by oligomerization using well known automated phosphoramidite chemistry using a phosphoramidite compound having the following structure (IV): wherein:

[0259] R1" and R2" are, at each occurrence, independently H, a protecting group, or an activated phosphorus moiety;

[0260] R4" is alkoxy, haloalkyl, alkyl, an optionally substituted aryl or an optionally substituted aralkyl.

[0261] In some embodiments of compound of structure (IV), R1" is H. In certain embodiments, is a protecting group, for example, a trityl protecting group. In some embodiments, R1" is trityl. In some embodiments, R1" is 4-methoxytrityl. In more specific embodiments, R1" is 4,4'- dimethoxytrityl. In some embodiments, R2" is H. In some embodiments, R2" is an activated phosphorus moiety. For example, in some embodiments R2" comprises the following structure: wherein:

[0262] R5" is H or cyano alkyl; and

[0263] R6" is, at each occurrence, independently Ci-Ce alkyl.

[0264] In some embodiments of compound of structure (IV), R5" is H. In other embodiments, R5" is 2-cyanoethyl.

[0265] In some embodiments, at least one occurrence of R6" is isopropyl. In some embodiments, each occurrence of R6" is isopropyl.

[0266] In certain specific embodiments, R2" has the following structure:

[0267] In some embodiments of compound of structure (IV), R4" is C1-C4 haloalkyl. In more specific embodiments, R4" is -CFs. In some embodiments, R4" is C1-C4 alkoxy. In more specific embodiments, R4" is methoxy.

[0268] In some specific embodiments, a compound of structure (IV) has the following structure:

[0269] Alternatively, compounds of structure (I) may be prepared by first synthesizing compounds of structure (V) and then coupling the fluorescent or colored dyes M1and biologically active moieties M2to the compounds of structure (V). Accordingly, some embodiments provide intermediate compounds having structure (V): wherein:

[0270] G is, at each occurrence, independently a moiety comprising a reactive group, a group convertible into a reactive group, or protected analogue thereof, capable of forming a covalent bond with an amine group;

[0271] G1is, at each occurrence, independently a moiety comprising a reactive group, or protected analogue therefore, capable of forming a covalent bond with a complementary reactive group in M1, provided G1does not react with an amine group .

[0272] L1and L7are at each occurrence, independently an alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenylene, heteroalkynylene, arylene or heteroarylene linker or combinations thereof;

[0273] L2, L3, L5, and L6are, at each occurrence, independently absent or an alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenyl ene or heteroalkynylene linker;

[0274] L4is, at each occurrence, independently an alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenylene or heteroalkynylene linker;

[0275] R1and R2are each independently H, OH, SH, alkyl, alkoxy, alkylether, heteroalkyl, -OP(=Ra)(Rb)Rc, or Q;

[0276] R3is, at each occurrence, independently H, alkyl or alkoxy;

[0277] R4is, at each occurrence, independently OH, SH, O', S', ORd or SRd;

[0278] R5is, at each occurrence, independently oxo, thioxo or absent;

[0279] R5and R7are, at each occurrence, independently H, OH, or halo;

[0280] Ra is O or S;

[0281] Rb is OH, SH, O', S', ORd or SRd;

[0282] Re is OH, SH, O', S', ORd, OL', SRd, alkyl, alkoxy, heteroalkyl, heteroalkoxy, alkylether, alkoxyalkylether, phosphate, thiophosphate, phosphoalkyl, thiophosphoalkyl, phosphoalkylether or thiophosphoalkylether;

[0283] Rd is a counter ion; Q is, at each occurrence, independently a moiety comprising a reactive group, or protected form thereof, capable of forming a covalent bond with a complementary reactive group Q' on a targeting moiety;

[0284] L' is, at each occurrence, independently a linker comprising a covalent bond to Q, a targeting moiety, a linker comprising a covalent bond to a targeting moiety, a linker comprising a covalent bond to a solid support, a linker comprising a covalent bond to a solid support residue, a solid support residue, a linker comprising a covalent bond to a nucleoside, or a linker comprising a covalent bond to a further compound of Structure (I); m and p are, at each occurrence, independently an integer of zero or greater; w is, at each occurrence, an integer of one or greater; and n is an integer of one or greater.

[0285] The G1moiety in the compound of structure (V) can be selected from any moiety comprising a group having the appropriate reactivity group for forming a covalent bond with a complementary group on an M1moiety. In some embodiments, G1at each occurrence, independently comprises a moiety suitable for reactions including: the copper catalyzed reaction of an azide and alkyne to form a triazole (Huisgen 1, 3-dipolar cycloaddition), reaction of a diene and dienophile (Diels-Alder), strain-promoted alkyne-nitrone cycloaddition, reaction of a strained alkene with an azide, tetrazine or tetrazole, alkene and azide [3+2] cycloaddition, alkene and tetrazine inverse-demand Diels- Alder, alkene and tetrazole photoreaction and various displacement reactions, such as displacement of a leaving group by nucleophilic attack on an electrophilic atom.

[0286] In some embodiments, G1is, at each occurrence, independently a moiety comprising an oxime, hydrazone, alkyne, amine, azide, acylazide, acylhalide, nitrile, nitrone, sulfhydryl, disulfide, sulfonyl halide, isothiocyanate, imidoester, activated ester, ketone, a,[3-unsaturated carbonyl, alkene, maleimide, a-haloimide, epoxide, aziridine, tetrazine, tetrazole, phosphine, biotin or thiirane functional group.

[0287] In some embodiments, G1at each occurrence, independently comprises an alkyne or an azide group. In other embodiments, G1at each occurrence, independently comprises an amino, isothiocyanate or activated ester group. In different embodiments, G1at each occurrence, independently comprises a reactive group capable of forming a functional group comprising an alkene, ester, amide, thioester, disulfide, carbocyclic, heterocyclic or heteroaryl group, upon reaction with the complementary reactive group. For example, in some embodiment the heteroaryl is triazolyl. In other of any of the foregoing embodiments of compound (V), G1is, at each — | - - U N3occurrence, independently ? or ? . In some embodiments, at least one occurrence of G1has one of the following structures:

[0288] —5-N3—s - — NH

[0289] ? ; ? or ?22 .

[0290] In some related embodiments, G1, at each occurrence, independently have one of the following structures:

[0291] In some embodiments of compound of structure (V), at least one occurrence of G1is . In more specific embodiments, G1is, at each occurrence, independently-

[0292] In some embodiments of compound (V), at least one occurrence of G1is a protected form of an amine. In some embodiments, G1is, at a plurality of occurrences, independently a protected form of an amine. In certain embodiments, G1is, at each occurrence, independently a protected form of an amine.

[0293] In some of the foregoing embodiments, the protected form of the amine is a trifluoroacetate protected amine. In some embodiments, the protected form of the amine is a BOC protected amine. In some embodiments, the protected form of the amine is an Fmoc protected amine. For example, in certain embodiments, at least one occurrence of G1has one of the following structures:

[0294] In more specific embodiments, G1, at each occurrence, independently has one of the following structures:

[0295] In some embodiments, L7-G1has one of the following structures:

[0296] In some embodiments, R1, R2, R3, R4, R5, R6, R7, L2, L3, L4, L5, or L6are as defined in any one of the foregoing embodiments.

[0297] In some embodiments, G is, at each occurrence, independently -C(=O)OH or -C(=O)H.

[0298] In some related embodiments, the compound of structure (V) has the following structure (VA) or (VB):

[0299] The linker L1can be used as a point of attachment of the G group to the reminder of the compound.

[0300] In some embodiments, at least one occurrence of L1comprises a linker that is non- cleavable under physiological conditions. Accordingly, in some embodiments, L1comprises an amide bond, an ester bond, a disulfide bond, a hydrazone, a phosphotriester, a diester, P- glucuronide, a double bond, a triple bond, an ether bond, a ketone, a diol, or combinations thereof.

[0301] In some embodiments, L1comprises tert-butyloxycarbonyl, paramethoxybenzyl, dialkyl or diaryldialkoxysilane, orthoester, acetal, P-thiopropionate, ketal, phosphoramidate, hydrazone, vinyl ether, imine, aconityl, trityl, polyketal, bisarylhydrazone, diazobenzene, vivinal diol, pyrophosphate diester, or valine citrulline. In certain embodiments, L1is, at each occurrence, independently a linker that is cleavable at a pH ranging from 6 to 8. For example, in some embodiments L1is a linker that is cleavable at pH 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, or 8.0.

[0302] In some embodiments, L1is, at each occurrence, independently a linker that is cleavable at a temperature ranging from 20°C to 40°C, from 25°C to 35°C, from 30°C to 35°C, from 30°C to 37°C, from 35°C to 37°C, from 35°C to 40°C, from 32°C to 38°C. In certain embodiments, L is, at each occurrence, independently a linker that is cleavable at a temperature of about 20°C, about 21°C, about 22°C, about 23°C, about 24°C, about 25°C, about 26°C, about 27°C, about 28°C, about 29°C, about 30°C, about 31°C, about 32°C, about 33°C, about 34°C, about 35°C, about 36°C, about 37°C, about 38°C, about 39°C, or about 40°C.

[0303] In certain embodiments, L1is, at each occurrence, independently a linker that is cleavable by an enzyme. For example, in some embodiments, the enzyme is a hydrolase, an oxidoreductase or a lyase. In certain embodiments, the enzyme is an EC 4.1 (e.g., EC 4.1.1, EC 4.1.2, EC 4.1.3 or EC 4.1.99), EC 4.2, EC 4.3, EC4.4, EC 4.5, EC 4.6, or EC 4.99 enzyme.

[0304] In some embodiments, for at least one occurrence of L1, L^G has the following structure: -j-L1a-L1 b-G

[0305] In some embodiments, at least one occurrence of Llais an optionally substituted 5-9 membered heteroarylene linker. In certain embodiments, Llais a substituted 5-membered heteroarylene linker. In certain embodiments, Llais a substituted 6-membered heteroarylene linker. In certain embodiments, Llais a substituted 7-membered heteroarylene linker. In certain embodiments, Llais a substituted 8-membered heteroarylene linker. In certain embodiments, Llais a substituted 9-membered heteroarylene linker. In some related embodiments, Llais substituted with oxo, alkyl (e.g., methyl, ethyl, etc.) or combinations thereof. In certain embodiments, Llais, at each occurrence, unsubstituted. In some more specific embodiments, Llais, at each occurrence independently a pyrimidine. In some more specific embodiments, Llais, at each occurrence, independently cytosine or thymine. In some embodiments, Llais, at each occurrence, independently selected from cytosine and thymine such that the compound comprises a sequence of cytosine and thymine bases capable of triplex formation with a target DNA sequence.

[0306] In some embodiments, Llahas one of the following structures:

[0307] In some embodiments, Llbis, at each occurrence, independently an optional alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenyl ene, heteroalkynylene, alkyl eneheteroary 1 enealkyl ene, alky 1 eneheterocy cly 1 enealky 1 ene, alkyl enecarb ocy cly 1 enealky 1 ene, heteroalkyl eneheteroary 1 enealky 1 ene, heteroalkyleneheterocyclylenealkylene, heteroalkylenecarbocyclylenealkylene, heteroalkyleneheteroaryleneheteroalkylene, heteroalkyleneheterocyclyleneheteroalkylene, heteroalkylenecarbocyclyleneheteroalkylene, alkyleneheteroaryleneheteroalkylene, alkyl eneheterocyclyleneheteroalkylene, alkylenecarbocyclyleneheteroalkylene, heteroarylene, heterocyclylene, carbocyclylene, alkyleneheteroarylene, alkyleneheterocyclylene, heteroarylenealkylene, alkylenecarbocyclylene, carbocyclylenealkylene, heteroalkyleneheteroarylene, heteroalkyleneheterocyclylene, heteroaryleneheteroalkylene, heteroalkylenecarbocyclylene, carbocyclyleneheteroalkylene or heteroatomic linker. In some embodiments, Llbis an optionally substituted heteroalkenylene linker.

[0308] J-L1a-L1 bL

[0309] In some more specific embodiments, Laand I? together (z.e., ? ? ) has one of the following structures:

[0310] In some embodiments, at least one occurrence of L1comprises one or more amino acid residues. In some embodiments, the amino acid residue is valine. In certain embodiments, at least one occurrence of L1comprises one of the following structures:

[0311] In some embodiments, at least one occurrence of L1comprises one of the following structures: In some embodiments, at least one occurrence of L4is heteroalkylene. In some embodiments, each occurrence of L4is heteroalkylene. In some embodiments, at least one occurrence of L4comprises alkylene oxide. In some more specific embodiments, the alkylene oxide of L4is ethylene oxide. In some more specific embodiments, the ethylene oxide is polyethylene oxide. In certain embodiments, L4, at each occurrence, has the following structure: wherein: z is an integer from 1 to 100; and

[0312] * indicates a bond to the adjacent phosphorous atom.

[0313] In some embodiments, the compound of structure (V) has the following structure (VC) or (VD):

[0314] In some embodiments, L2, L3, L5, and L6are, at each occurrence, independently absent (z'.e., a direct bond) or independently an alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenylene or heteroalkynylene linker. In some embodiments, L2, L3, L5, and L6are, at each occurrence, independently alkylene. In more embodiments, L2, L3, L5, and L6are, at each occurrence, independently Ci-Ce alkylene, C2-C6 alkenylene or C2-C6 alkynylene. In some more specific embodiments, the alkylene linker of L2, L3, L5, and L6is a Ci alkylene linker. In some more specific embodiments, the alkylene linker of L2, L3, L5, and L6is a C2 alkylene linker. In some more specific embodiments, the alkylene linker of L2, L3, L5, and L6is a C3 alkylene linker. In some more specific embodiments, the alkylene linker of L3and L5is a C4 alkylene linker. In some more specific embodiments, the alkylene linker of L2, L3, L5, and L6is a Cs alkylene linker. In some more specific embodiments, the alkylene linker of L2, L3, L5, and L5is a C& alkylene linker. In some other embodiments, at least one occurrence of L2, L3, L5, and L6are a direct bond. In certain embodiments, at least one occurrence of L2is absent. In more specific embodiments, L2is absent at each occurrence.

[0315] In some related embodiments, the compound of structure (V) has the following structure (VE) or (VF): wherein y1, y2, y3, and y4are, at each occurrence, independently an integer from 0 to 6.

[0316] In some embodiments, y1, y2, y3, and y4are, at each occurrence, an integer 0 (z.e., each of L2, L3, L5, and L6is a direct bond). In some embodiments, y1, y2, y3, and y4are, at each occurrence, an integer 1. In some embodiments, y1, y2, y3, and y4are, at each occurrence, an integer 2. In some embodiments, y1, y2, y3, and y4are, at each occurrence, an integer 3. In some embodiments, y1, y2, y3, and y4are, at each occurrence, an integer 4. In some embodiments, y1, y2, y3, and y4are, at each occurrence, an integer 5. In some embodiments, y1, y2, y3, and y4are, at each occurrence, an integer 6. In some more specific embodiments, y1, y2, y3, and y4are each 0 or 1 at each occurrence.

[0317] In some embodiments, the compound of structure (V) is a compound selected from Table 4.

[0318] Table 4. Exemplary Compounds of Structure V

[0319]

[0320] Reaction Scheme III

[0321] Reaction Scheme III illustrates an exemplary method for preparing a compound of structure (I), wherein M1, G1, G1, R1, R2, R3, R4, R5, R6, R7, L1, L2, L3, L4, L5, L6, L7, L7, m, n, p, and w are as defined above. Compound of structure (V) is reacted with M^G1to yield compound of structure (I). Here, G1and G1represent functional groups having complementary reactivity (i.e., functional groups which react to form a covalent bond). G1may be pendant to M1or a part of the structural backbone of M1. G1and G1may be any number of functional groups described herein, such as alkyne and azide, respectively, amine and activated ester, respectively or amine and isothiocyanate, respectively, and the like. For example, in some embodiments, when G1is -NH2, G1is -C(=O)OH.

[0322] Compounds of structure (V) may be prepared by DNA synthesis methodology described above.

[0323] It will be appreciated by those skilled in the art that in the process described herein the functional groups of intermediate compounds may need to be protected by suitable protecting groups. Such functional groups include hydroxy, amino, mercapto and carboxylic acid. Suitable protecting groups for hydroxy include trialkylsilyl or diarylalkylsilyl (for example, t- butyldimethylsilyl, t-butyldiphenyl silyl or trimethyl silyl), tetrahydropyranyl, benzyl, and the like. Suitable protecting groups for amino, amidino and guanidino include t-butoxycarbonyl, benzyloxycarbonyl, and the like. Suitable protecting groups for mercapto include -C(O)-R" (where R" is alkyl, aryl or arylalkyl), p-methoxybenzyl, trityl and the like. Suitable protecting groups for carboxylic acid include alkyl, aryl or arylalkyl esters. Protecting groups may be added or removed in accordance with standard techniques, which are known to one skilled in the art and as described herein. The use of protecting groups is described in detail in Green, T.W. and P.G.M. Wutz, Protective Groups in Organic Synthesis (1999), 3rd Ed., Wiley. As one of skill in the art would appreciate, the protecting group may also be a polymer resin such as a Wang resin, Rink resin, or a 2-chlorotrityl-chloride resin.

[0324] Furthermore, all compounds of the disclosure which exist in free base or acid form can be converted to their salts by treatment with the appropriate inorganic or organic base or acid by methods known to one skilled in the art. Salts of the compounds of the disclosure can be converted to their free base or acid form by standard techniques.

[0325] EXAMPLES

[0326] General Methods

[0327] Mass spectral analysis is performed on a Waters / Micromass Quattro micro MS / MS system (in MS only mode) using MassLynx 4.1 acquisition software. Mobile phase used for LC / MS on dyes is 100 mM l,l,l,3,3,3-hexafluoro-2-propanol (HFIP), 8.6 mM triethylamine (TEA), pH 8. Phosphoramidites and precursor molecules are also analyzed using a Waters Acquity UHPLC system with a 2.1 mm x 50 mm Acquity BEH-Cis column held at 45 °C, employing an acetonitrile / water mobile phase gradient. Molecular weights for monomer intermediates are obtained using tropylium cation infusion enhanced ionization on a Waters / Micromass Quattro micro MS / MS system (in MS only mode). Excitation and emission profiles experiments are recorded on a Cary Eclipse spectra photometer.

[0328] All reactions are carried out in oven dried glassware under a nitrogen atmosphere unless otherwise stated. Commercially available DNA synthesis reagents are purchased from Glen Research (Sterling, VA). Anhydrous pyridine, toluene, di chloromethane, diisopropylethyl amine, tri ethyl amine, acetic acid, pyridine, and THF are purchased from Aldrich. All other chemicals are purchase from Aldrich or TCI and are used as is with no additional purification. EXAMPLE 1

[0329] SYNTHESIS OF COMPOUND 1-1 AND COMOPUND 1-2

[0330] Compound 1-1 and Compound 1-2 were prepared by automated solid-phase synthesis (SPS) using standard phosphoramidite chemistry; analogous to the synthesis chemistry used for oligonucleotide synthesis. The synthesis process involves: solid phase synthesis, final deprotection and cleavage from the solid support, isolation of the compound, and analysis. The general solid phase synthesis process is a repetitive cycle of four steps, with solvent washes in between each step, as follows: step 1- detrityl ati on, step 2- monomer coupling, step 3-oxidation, and step 4-capping. The synthesis cycle is repeated until all of the monomers have been sequentially incorporated into the polymer. The solid phase synthesis of each of Compound 1-1 and Compound 1-2 was conducted using an AKTA oligopilot™ Plus synthesizer, UNICORN control software, and standard oligonucleotide synthesis programing steps. The AKTA synthesis columns were loaded with solid support, 0.13 g (40 pmole) of Primer Support 5G T 300 purchased from Cytiva. The phosphoramidite monomers used in the synthesis (e.g., hexaethylene glycol phosphoramidite, 6-FAM phosphoramidite, 5'-thiol C-6 disulfide modifier CED phosphoramidite, carboxy-dT phosphoramidite) were dissolved in anhydrous acetonitrile at 0.2 M concentration and loaded onto the AKTA system. During the monomer coupling steps, 240 pmole (6 equivalents) of phosphoramidite monomer was delivered to the solid support and allowed sufficient contact time to complete the coupling reaction. At the completion of solid phase synthesis, Compound 1-1 and Compound 1-2 were deprotected and cleaved from the solid support using 20 mL of 0.4 M sodium hydroxide solution in methanol / water (80:20), for 18 hours, at 37 °C. The solid support was then separated from the compound containing solution by filtration, the solid support was washed three times with 5 mL of ethanol / water (50:50), the filtrates combined, and the filtrate solution was neutralized with 60 mL of 2 M triethylammonium acetate solution in water. The compound containing solutions were de-salted by ultrafiltration (Microsep centrifugal filter with Omega modified polyethersulfone membrane and IK MWCO, PALL Corporation). The desalted compound containing solutions were then sampled for LC-UV / MS analysis, UV absorption spectroscopy analysis, and then concentrated to a dry residue by evaporation and lyophilization. Compound 1-1 yield was 74 mg (by UV spec. 266 nm), -85% purity (by LC-UV, diode array), and observed mass 2530.6 (by mass spectrometry). Compound 1-2 yield was 109 mg (by UV spec. 266 nm), -83% purity (by LC- UV, diode array), and observed mass 3923.6 (by mass spectrometry). All of the U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and / or listed in the Applicant Data Sheet, including U.S. Provisional Patent Application No. 63 / 587,602, filed October 3, 2023, are incorporated herein by reference, in their entirety to the extent not inconsistent with the present description. Aspects of the embodiments can be modified, if necessary to employ concepts of the various patents, applications and publications to provide yet further embodiments.

[0331] From the foregoing it will be appreciated that, although specific embodiments of the disclosure have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the disclosure. Accordingly, the disclosure is not limited except as by the appended claims.

Claims

CLAIMSWhat is claimed is:

1. A method for preparing a polymer-drug conjugate, the method comprising reacting a compound of structure (I):with a compound of structure (II):M2-NHR8(II) wherein:M1is, at each occurrence, independently a moiety comprising a fluorescent or colored dye;M2is a moiety comprising a biologically active moiety or a fluorescent or colored dye;G is, at each occurrence, independently a moiety comprising a reactive group, a group convertible into a reactive group, or protected analogue thereof, capable of forming a covalent bond with an amine group;L1and L7are at each occurrence, independently absent or an alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenylene, heteroalkynylene, arylene or heteroarylene linker or combinations thereof;L2, L3, L5, and L5are, at each occurrence, independently absent or an alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenyl ene or heteroalkynylene linker;L4is, at each occurrence, independently an alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenylene or heteroalkynylene linker;R1and R2are each independently H, OH, SH, alkyl, alkoxy, alkylether, heteroalkyl, -OP(=Ra)(Rb)Rc, or Q;R3is, at each occurrence, independently H, alkyl or alkoxy;R4is, at each occurrence, independently OH, SH, O', S', ORd or SRa;R5is, at each occurrence, independently oxo, thioxo or absent;R6and R7are, at each occurrence, independently H, OH, or halo;R8is H or alkyl;Ra is O or S;Rb is OH, SH, O', S', ORa or SRa;Re is OH, SH, O', S', ORa, OL', SRd, alkyl, alkoxy, heteroalkyl, heteroalkoxy, alkylether, alkoxyalkylether, phosphate, thiophosphate, phosphoalkyl, thiophosphoalkyl, phosphoalkylether or thiophosphoalkylether;Rd is a counter ion;Q is, at each occurrence, independently a moiety comprising a reactive group, or protected form thereof, capable of forming a covalent bond with a complementary reactive group Q' on a targeting moiety;L' is, at each occurrence, independently a linker comprising a covalent bond to Q, a targeting moiety, a linker comprising a covalent bond to a targeting moiety, a linker comprising a covalent bond to a solid support, a linker comprising a covalent bond to a solid support residue, a solid support residue, a linker comprising a covalent bond to a nucleoside, or a linker comprising a covalent bond to a further compound of structure (I); m and p are, at each occurrence, independently an integer of zero or greater; w is, at each occurrence, independently an integer of one or greater; and n is an integer of one or greater, thereby: i) forming a first bond between G of the compound of structure (I) and -NHR8of the compound of structure (II).

2. The method of claim 1, wherein G is -C(=O)OH or -C(=O)H.

3. The method of claim 2, wherein the compound of structure (I) has the following structure (IA) or (IB):

4. The method of any one of claims 1-3, wherein L4has following structure:4(OCH2CH2)Z-J- wherein: z is an integer from 1 to 100; and* indicates a bond to the adjacent phosphorous atom.

5. The method of claim 4, wherein z is an integer from 3 to 8.

6. The method of claim 4, wherein z is an integer from 22 to 26.

7. The method of any one of claims 3-6, wherein the compound of structure (I) haswherein m is an integer from 0 to 10.

8. The method of claim 7, wherein m is 1.

9. The method of any one of claims 1-8, wherein L2, L3, L5, and L6are, at each occurrence, independently absent or Ci-Ce alkylene, C2-C6 alkenylene or C2-C6 alkynylene.

10. The method of any one of claims 3-9, wherein the compound of structure (I) has the following structure (IE) or (IF):wherein y1, y2, y3and y4are, at each occurrence, independently an integer from 0 to 6.

11. The method of claim 10, wherein y1, y2, y3and y4are, at each occurrence, 0 or 1.

12. The method of any one of claims 1-11, wherein L1comprises an amide bond, an ester bond, a disulfide bond, a hydrazone, a phosphotriester, a diester, p -glucuronide, a double bond, a triple bond, an ether bond, a ketone, a diol, or combinations thereof.

13. The method of claim 12, wherein L1comprises tert-butyloxycarbonyl, paramethoxybenzyl, dialkyldialkoxysilane, diaryldialkoxysilane, orthoester, acetal, P- thiopropionate, ketal, phosphoramidate, hydrazone, vinyl ether, imine, aconityl, trityl, polyketal, bisarylhydrazone, diazobenzene, vivinal diol, pyrophosphate diester or valine citrulline.

14. The method of any one of claims 1-11, wherein L1comprises one of the following structures:

15. The method of any one of claims 1-11, wherein L1comprises one of the following structures:

16. The method of any one of claims 1-11, wherein L1comprises one of the following structures:

17. The method of any one of claims 1-16, wherein L7has one of the following structures:

18. The method of claim 17, wherein L7is:

19. The method of any one of claims 1-16, wherein L7has one of the following structures:

20. The method of any one of claims 1-16, wherein L7has one of the following structures:

21. The method of any one of claims 1-20, wherein R3is H.

22. The method of any one of claims 1-21, wherein R4is O', OH or ORd.

23. The method of any one of claims 1-22, wherein R5is oxo.

24. The method of any one of claims 1-23, wherein R6and R7are H.

25. The method of any one of claims 1-24, wherein one of R1or R2is -OP(=Ra)(Rb)Rc, and the other of R1or R2is Q.

26. The method of claim 25, wherein Q comprises a nucleophilic reactive group, an electrophilic reactive group or a cycloaddition reactive group.

27. The method of claim 26, wherein Q comprises a sulfhydryl, disulfide, activated ester, isothiocyanate, azide, alkyne, alkene, diene, dienophile, acid halide, sulfonyl halide, phosphine, oc-haloamide, biotin, amino or maleimide functional group.

28. The method of claim 27, wherein the activated ester is an N-succinimide ester, imidoester or polyflourophenyl ester.

29. The method of claim 27, wherein the azide is an alkyl azide or acyl azide.

30. The method of any one of claims 25-29, wherein Q is a moiety selected from Table 1.

31. The method of any one of claims 1-24, wherein R1and R2are each independently -OP(=Ra)(Rb)Rc.

32. The method of any one of claims 25-31, wherein Rc is OL'.

33. The method of claim 32, wherein L1is a targeting moiety.

34. The method of claim 32, wherein L1is a linker to a targeting moiety, a linker to an analyte molecule or a linker to a solid support, the linker comprising an alkylene oxide or phosphodiester moiety, or combinations thereof.

35. The method of any one of claims 32-34, wherein L' has the following structure:wherein: m" and n" are independently an integer from 1 to 10;Reis H, an electron pair or a counter ion; andL" is the targeting moiety or a linkage to the targeting moiety.

36. The method of claim 35, wherein n" is 6.

37. The method of any one of claims 33-36, wherein the targeting moiety is an antibody or cell surface receptor antagonist.

38. The method of claim 37, wherein the antibody or cell surface receptor antagonist is an epidermal growth factor receptor (EGFR) inhibitor, a hepatocyte growth factor receptor (HGFR) inhibitor, an insulin-like growth factor receptor (IGFR) inhibitor, a folate, or a MET inhibitor.

39. The method of claim 38, wherein the targeting moiety is a monoclonal antibody.

40. The method of any one of claims 34-39, wherein the analyte molecule is a nucleic acid, amino acid or a polymer thereof.

41. The method of any one of claims 34-39, wherein the analyte molecule is an enzyme, receptor, receptor ligand, glycoprotein, aptamer or prion.

42. The method of any one of claims 34-39, wherein the solid support is a polymeric bead or nonpolymeric bead.

43. The method of any one of claims 25-42, wherein R1or R2has one of the following structures:

44. The method of any one of claims 25-42, wherein R1or R2has the following structure:

45. The method of any one of claims 1-44, wherein M1has one of the following structures:

46. The method of claim 45, wherein M1is47. The method of claim 6, wherein L7-Mxhas the following structure:

48. The method of any one of claims 1-44, wherein M1has one of the following structures:

49. The method of any one of claims 1-48, wherein p is an integer from 0 to 4.

50. The method of claim 49, wherein p is 1.

51. The method of any one of claims 1-50, wherein w is an integer from 1 to 20.

52. The method of claim 51, wherein w is an integer from 1 to 10.

53. The method of claim 52, wherein w is 1.

54. The method of claim 52, wherein w is 2.

55. The method of any one of claims 1-54, wherein n is an integer from 1 to 20.

56. The method of claim 55, wherein n is 1.

57. The method of any one of claims 1-56, wherein the compound of structure (I) is a compound selected from Table 2.

58. The method of any one of claims 1-57, wherein M2is an antineoplastic agent.

59. The method of claim 58, wherein the antineoplastic agent is paclitaxel, camptonthecin, doxorubicin, monomethyl auristatin E (MMAE), MMAE-Val-Cit or monomethyl auristatin F.

60. The method of any one of claims 58-59, wherein the antineoplastic agent is monomethyl auristatin E.

61. The method of any one of claims 58-59, wherein the antineoplastic agent is MMAE-Val-Cit.

62. The method of any one of claims 58-59, wherein the antineoplastic agent is doxorubicin.

63. The method of any one of claims 58-59, wherein M2has one of the following structures:

64. The method of any one of claims 1-58, wherein M2is an antitumor antibiotic.

65. The method of claim 64, wherein M2is selected from the group consisting of peplomycin sulfate, pirarubicin hydrochloride, zinostatin stimalamer, idarubicin hydrochloride,mitomycin C, bleomycin hydrochloride, doxorubicin hydrochloride, daunorubicin hydrochloride and epirubicin hydrochloride.

66. The method of claim 64, wherein M2is an enediyne antitumor antibiotic.

67. The method of claim 66, wherein the enediyne antitumor antibiotic is calicheamicin.

68. The method of any one of claims 1-67, wherein R8is H or ethyl.

69. The method of any one of claims 58-68, wherein the compound of structure (II) has one of the following structures:

70. The method of any one of claims 1-69, wherein the reaction of the compound of structure (I) and the compound of structure (II) is carried out in a solution comprising the compound of structure (I) and the compound of structure (II).

71. The method of claim 70, wherein the solution further comprises a solvent selected from the group consisting of dimethylsulfoxide (DMSO), N-methylformamide (NMP), N- methylpyrrolidone, dimethylacetamide, dimethylformamide (DMF), dichloromethane, di chloroethane, chloroform, and combinations thereof.

72. The method of claim 71, wherein the solvent is DMF.

73. The method of any one of claim 70-72, wherein the solution further comprises an activating agent.

74. The method of claim 73, wherein the activating agent is selected from the group consisting of 2-(H-benzotriazol-l-yl)-l,l,3,3-tetramethyluronium hexafluorophosphate (HBTU), O-(benzotriazol-l-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate (TBTU), 2-(lH-7- azabenzotriazol-l-yl)-l,l,3,3-tetramethyluronium hexafluorophosphate (HATU), 1- hydroxybenzotriazole reagent (HOBt), N,N'-dicyclohexyl carbodiimide (DCC), diisopropyl carbodiimide (DIPCDI), benzotriazol-l-yl-oxy-tris(dimethylamino)phosphonium hexafluorophosphate (BOP), benzotriazol- 1 -yl-oxytripyrrolidinophosphonium hexafluorophosphate (PyBOP), N-methylmorpholine (NMM), and a combination thereof.

75. The method of claim 74, wherein the activating agent is HBTU.

76. The method of any one of claims 70-75, wherein the solution further comprises a base selected from the group consisting of diisopropylethylamine (DIPEA), triethylamine, piperidine, pyrrolidine, pyridine, N-methylmorpholin (NMM), collidine and combinations thereof.

77. A compound have the following structure (I):wherein:M1is, at each occurrence, independently a moiety comprising a fluorescent or colored dye;G is, at each occurrence, independently a moiety comprising a reactive group, a group convertible into a reactive group, or protected analogue thereof, capable of forming a covalent bond with an amine group;L1and L7are at each occurrence, independently absent or an alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenylene, heteroalkynylene, arylene or heteroarylene linker or combinations thereof;L2, L3, L5, and L6are, at each occurrence, independently absent or an alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenyl ene or heteroalkynylene linker;L4is, at each occurrence, independently an alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenylene or heteroalkynylene linker;R1and R2are each independently H, OH, SH, alkyl, alkoxy, alkylether, heteroalkyl, -OP(=Ra)(Rb)Rc, or Q;R3is, at each occurrence, independently H, alkyl or alkoxy;R4is, at each occurrence, independently OH, SH, O', S', ORd or SRa;R5is, at each occurrence, independently oxo, thioxo or absent;R5and R7are, at each occurrence, independently H, OH, or halo;Ra is O or S;Rb is OH, SH, O', S', ORd or SRd;Re is OH, SH, O', S', ORa, OL', SRa, alkyl, alkoxy, heteroalkyl, heteroalkoxy, alkylether, alkoxyalkylether, phosphate, thiophosphate, phosphoalkyl, thiophosphoalkyl, phosphoalkylether or thiophosphoalkylether;Rd is a counter ion;Q is, at each occurrence, independently a moiety comprising a reactive group, or protected form thereof, capable of forming a covalent bond with a complementary reactive group Q' on a targeting moiety;L' is, at each occurrence, independently a linker comprising a covalent bond to Q, a targeting moiety, a linker comprising a covalent bond to a targeting moiety, a linker comprising a covalent bond to a solid support, a linker comprising a covalent bond to a solid support residue, a solid support residue, a linker comprising a covalent bond to a nucleoside, or a linker comprising a covalent bond to a further compound of structure (I); m and p are, at each occurrence, independently an integer of zero or greater; w is, at each occurrence, independently an integer of one or greater; and n is an integer of one or greater.

78. The compound of claim 77, wherein G is -C(=O)OH or -C(=O)H.

79. The compound of any one of claims 77-78, wherein the compound of structure (I) has following structure (IA) or (IB):

80. A compound having the following structure (III):wherein:M1is, at each occurrence, independently a moiety comprising a fluorescent or colored dye;M2is, at each occurrence, independently a moiety comprising a biologically active moiety or a fluorescent or colored dye, provided at least one occurrence of M2is a biologically active moiety;L1and L7are at each occurrence, independently absent or an alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenylene, heteroalkynylene, arylene or heteroarylene linker or combinations thereof;L2, L3, L5, and L6are, at each occurrence, independently absent or an alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenyl ene or heteroalkynylene linker;L4is, at each occurrence, independently an alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenylene or heteroalkynylene linker;R1and R2are each independently H, OH, SH, alkyl, alkoxy, alkylether, heteroalkyl, -OP(=Ra)(Rb)Rc, or Q;R3is, at each occurrence, independently H, alkyl or alkoxy;R4is, at each occurrence, independently OH, SH, O', S', ORd or SRd;R5is, at each occurrence, independently oxo, thioxo or absent;R5and R7are, at each occurrence, independently H, OH, or halo;Ra is O or S;Rb is OH, SH, O', S', ORd or SRd;Re is OH, SH, O', S', ORd, OL', SRd, alkyl, alkoxy, heteroalkyl, heteroalkoxy, alkylether, alkoxyalkylether, phosphate, thiophosphate, phosphoalkyl, thiophosphoalkyl, phosphoalkylether or thiophosphoalkylether;Rd is a counter ion;Q is, at each occurrence, independently a moiety comprising a reactive group, or protected form thereof, capable of forming a covalent bond with a complementary reactive group Q' on a targeting moiety;L' is, at each occurrence, independently a linker comprising a covalent bond to Q, a targeting moiety, a linker comprising a covalent bond to a targeting moiety, a linker comprising a covalent bond to a solid support, a linker comprising a covalent bond to a solid support residue, a solid support residue, a linker comprising a covalent bond to a nucleoside, or a linker comprising a covalent bond to a further compound of structure (III); m and p are, at each occurrence, independently an integer of zero or greater; w is, at each occurrence, independently an integer of one or greater; and n is an integer of one or greater.

81. The method of claim 80, wherein L1comprises one of the following structures:

82. The method of claim 80, wherein L1comprises one of the following structures:

83. The method of claim 80, wherein L1comprises one of the following structures:

84. The compound of any one of claims 80-83, wherein M2has one of the following structures:

85. The compound of any one of claims 80-84, wherein the compound of structure (III) is a compound selected from Table 3.

86. The compound of any one of claims 77-85, wherein L7comprises one of the following structures:

87. The compound of claim 86, wherein L7is:

88. The compound of any one of claims 77-85, wherein L7comprises one of the following structures:

89. The method of any one of claims 77-86, wherein L7comprises one of the following structures:The compound of any one of claims 77-89, wherein M1has one of the following structures:

91. The compound of any one of claims 77-90, wherein M1has one of the following structures:

92. A compound having the following structure (V):wherein:G is, at each occurrence, independently a moiety comprising a reactive group, a group convertible into a reactive group, or protected analogue thereof, capable of forming a covalent bond with an amine group;G1is, at each occurrence, independently a moiety comprising a reactive group, or protected analogue therefore, capable of forming a covalent bond with a complementary reactive group in M1, provided G1does not react with an amine group .L1and L7are at each occurrence, independently an alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenylene, heteroalkynylene, arylene or heteroarylene linker or combinations thereof;L2, L3, L5, and L6are, at each occurrence, independently absent or an alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenyl ene or heteroalkynylene linker;L4is, at each occurrence, independently an alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenylene or heteroalkynylene linker;R1and R2are each independently H, OH, SH, alkyl, alkoxy, alkylether, heteroalkyl, -OP(=Ra)(Rb)Rc, or Q;R3is, at each occurrence, independently H, alkyl or alkoxy;R4is, at each occurrence, independently OH, SH, O', S', ORd or SRa;R5is, at each occurrence, independently oxo, thioxo or absent;R6and R7are, at each occurrence, independently H, OH, or halo;R8is H or alkyl;Ra is O or S;Rb is OH, SH, O', S', ORd or SRa;Re is OH, SH, O', S', ORd, OL', SRd, alkyl, alkoxy, heteroalkyl, heteroalkoxy, alkylether, alkoxyalkylether, phosphate, thiophosphate, phosphoalkyl, thiophosphoalkyl, phosphoalkylether or thiophosphoalkylether;Rd is a counter ion;Q is, at each occurrence, independently a moiety comprising a reactive group, or protected form thereof, capable of forming a covalent bond with a complementary reactive group Q' on a targeting moiety;L' is, at each occurrence, independently a linker comprising a covalent bond to Q, a targeting moiety, a linker comprising a covalent bond to a targeting moiety, a linker comprising a covalent bond to a solid support, a linker comprising a covalent bond to a solid support residue, a solid support residue, a linker comprising a covalent bond to a nucleoside, or a linker comprising a covalent bond to a further compound of Structure (V); m and p are, at each occurrence, independently an integer of zero or greater; w is, at each occurrence, independently an integer of one or greater; and n is an integer of one or greater.

93. The compound of claim 92, wherein G1has one of the following structures:

94. The compound of claim 92, wherein G1has one of the following structures:

95. The compound of claim 92, wherein L7’-Gxhas one of the following structures:

96. The compound of any one of claims 92-95, wherein G is -C(=O)OH or -C(=O)H.

97. The compound of claim 96, wherein the compound of structure (V) has the following structure (VA) or (VB):

98. The compound of any one of claims 77-97, wherein L4has following structure:4(OCH2CH2)Z-[- wherein: z is an integer from 1 to 100; and* indicates a bond to the adjacent phosphorous atom.

99. The compound of claim 97, wherein z is an integer from 3 to 8.

100. The compound of claim 97, wherein z is an integer from 22 to 26.

101. The compound of any one of claims 77-100, wherein the compound of structure (I) has the following structure (IC) or (ID):wherein the compound of structure (III) has the following structures (IIIB):wherein the compound of structure (V) has the following structure (VC) or V(D):wherein m is an integer from 0 to 10.

102. The compound of claim 101, wherein m is 1.

103. The compound of any one of claims 77-102, wherein L2, L3, L5, and L6are, at each occurrence, independently absent or Ci-Ce alkylene, C2-C6 alkenylene or C2-C6 alkynylene.

104. The compound of claim 103, wherein the compound of structure (I) has the following structure (IE) or (IF):wherein the compound of structure (III) has the following structure (IIIC):wherein the compound of structure (V) has the following structure VE) or (VF):wherein y1, y2, y3and y4are, at each occurrence, independently an integer from 0 to 6.

105. The compound of claim 104, wherein y1, y2, y3and y4are, at each occurrence, 0 or106. The compound of any one of claims 77-79 and claims 92-105, wherein L1has one of the following structures:

107. The compound of any one of claims 77-79 and claims 92-106, wherein L1has one of the following structures:

108. The compound of any one of claims 77-79 and claims 92-107, wherein L1has one of the following structures:

109. The compound of any one of claims 77-108, wherein R3is H.

110. The compound of any one of claims 77-109, wherein R4is O', OH or ORd.

111. The compound of any one of claims 77-109, wherein R5is oxo.

112. The compound of any one of claims 77-111, wherein R6and R7are H.

113. The compound of any one of claims 77-112, wherein one of R1or R2is -OP(=Ra)(Rb)Rc, and the other of R1or R2is Q.

114. The compound of claim 113, wherein Q comprises a nucleophilic reactive group, an electrophilic reactive group or a cycloaddition reactive group.

115. The compound of claim 114, wherein Q comprises a sulfhydryl, disulfide, activated ester, isothiocyanate, azide, alkyne, alkene, diene, dienophile, acid halide, sulfonyl halide, phosphine, a-haloamide, biotin, amino or maleimide functional group.

116. The compound of claim 115, wherein the activated ester is an N-succinimide ester, imidoester or polyflourophenyl ester.

117. The compound of claim 115, wherein the azide is an alkyl azide or acyl azide.

118. The compound of any one of claim 113-117, wherein Q is a moiety selected from Table 1.

119. The compound of any one of claims 77-118, wherein R1and R2are each independently -OP(=Ra)(Rb)Rc.

120. The compound of any one of claims 113-119, wherein Rc is OL'.

121. The compound of claim 120, wherein L' is a targeting moiety.

122. The compound of claim 120, wherein L' is a linker to a targeting moiety, a linker to an analyte molecule or a linker to a solid support, the linker comprising an alkylene oxide or phosphodiester moiety, or combinations thereof.

123. The compound of claim 120, wherein L' has the following structure:wherein: m" and n" are independently an integer from 1 to 10;Reis H, an electron pair or a counter ion; andL" is the targeting moiety or a linkage to the targeting moiety.

124. The compound of claim 123, wherein n" is 6.

125. The compound of any one of claims 121-124, wherein the targeting moiety is an antibody or cell surface receptor antagonist.

126. The compound of claim 125, wherein the antibody or cell surface receptor antagonist is an epidermal growth factor receptor (EGFR) inhibitor, a hepatocyte growth factor receptor (HGFR) inhibitor, an insulin-like growth factor receptor (IGFR) inhibitor, a folate, or a MET inhibitor.

127. The compound of claim 125, wherein the targeting moiety is a monoclonal antibody.

128. The compound of claim 122, wherein the analyte molecule is a nucleic acid, amino acid or a polymer thereof.

129. The compound of claim 122, wherein the analyte molecule is an enzyme, receptor, receptor ligand, glycoprotein, aptamer or prion.

130. The compound of claim 122, wherein the solid support is a polymeric bead or nonpolymeric bead.

131. The compound of any one of claims 113-130, wherein R1or R2has one of the following structures:

132. The compound of any one of claims 113-130, wherein R1or R2has the following structure:

133. The compound of any one of claims 92-132, wherein the compound of structure (V) is a compound selected from Table 4.

134. A method for preparing a compound of structure (I) of claim 1 comprising reacting a compound of structure (V) of claim 92 with MLGr, wherein G1comprises a functional group having complementary reactivity with G1.

135. The method of claim 134, wherein G1is -C(=O)OH.

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