Abstract: The present invention provides, among other things, polymeric reagents suitable for reaction with biologically active agents to form conjugates, the polymeric reagents comprising one or more polymer chains and a plurality of hydroxyapatite-targeting moieties, and optionally the reagents include one or more degradable linkages that serve to divide the polymer chains into polymer segments having a molecular weight suitable for renal clearance.

Abstract: The present invention provides pharmaceutical compositions comprising a pharmaceutically acceptable excipient and a conjugate having a degradable linkage. The conjugates include at least one of each the following: an aromatic moiety comprising an ionizable hydrogen atom, a spacer moiety, and a water-soluble polymer. Methods for delivering such compositions are also provided.

Abstract: Multi-armed, monofunctional, and hydrolytically stable polymers are described having the structure wherein Z is a moiety that can be activated for attachment to biologically active molecules such as proteins and wherein P and Q represent linkage fragments that join polymer arms polya and polyb, respectively, to central carbon atom, C, by hydrolytically stable linkages in the absence of aromatic rings in the linkage fragments. R typically is hydrogen or methyl, but can be a linkage fragment that includes another polymer arm. A specific example is an mPEG disubstituted lysine having the structure where mPEGa and mPEGb have the structure CH3O—(CH2CH2O)nCH2CH2— where n may be the same or different for polya- and polyb- and can be from 1 to about 1,150 to provide molecular weights of from about 100 to 100,000.

Abstract: The invention provides polymer conjugates of opioid antagonists comprising a polymer, such as poly(ethylene glycol), covalently attached to an opioid antagonist. The linkage between the polymer and the opioid antagonist is preferably hydrolytically stable. The invention also includes a method of treating one or more side effects associated with the use of opioid analgesics, such as constipation, nausea, or pruritus, by administering a polymer conjugate of the invention.

Abstract: Provided herein are water-soluble prodrugs, compositions comprising such prodrugs, and related methods of making and administering the same. The prodrugs of the invention comprise a water-soluble polymer having three or more arms, at least three of which are typically covalently attached to an active agent, e.g., a small molecule. The conjugates of the invention provide an optimal balance of polymer size and structure for achieving improved drug loading, since the conjugates of the invention possess three or more active agents releasably attached to a multi-armed water-soluble polymer. The prodrugs of the invention are therapeutically effective, and exhibit improved properties in-vivo when compared to unmodified parent drug.

Abstract: Isolatable, hydroxyapatite-targeting polymeric structures, and biologically active conjugates thereof, are provided. The polymeric structure includes a linear or branched water-soluble and non-peptidic polymer backbone, such as a PEG backbone, having at least two termini, a first terminus being covalently bonded to a hydroxyapatite-targeting moiety, such as a bisphosphonate, and a second terminus covalently bonded to a chemically reactive group, wherein said chemically reactive group is protected or unprotected. Methods of preparing and using hydroxyapatite-targeting polymeric structures, and biologically active conjugates thereof, are also provided.

Abstract: The invention provides small molecule drugs that are chemically modified by covalent attachment of a water-soluble oligomer. A conjugate of the invention, when administered by any of a number of administration routes, exhibits characteristics that are different as compared to the characteristics of the small molecule drug not attached to the water-soluble oligomer.

Abstract: The invention provides methods for making copolymers and multi-arm block copolymers useful as drug delivery vehicles. The multi-arm block copolymers comprise a central core molecule, such as a residue of a polyol, and at least three copolymer arms covalently attached to the central core molecule, each copolymer arm comprising an inner hydrophobic polymer segment covalently attached to the central core molecule and an outer hydrophilic polymer segment covalently attached to the hydrophobic polymer segment, wherein the central core molecule and the hydrophobic polymer segment define a hydrophobic core region. The solubility of hydrophobic biologically active agents can be improved by entrapment within the hydrophobic core region of the block copolymer. The invention further includes pharmaceutical compositions including such block copolymers, pharmaceutical compositions, and methods of using the block copolymers as drug delivery vehicles.

Abstract: The present invention provides water-soluble, polymer derivatives having a thiol-selective terminus suitable for selective coupling to thiol groups, such as those contained in the cysteine residues of proteins, as well as methods for preparing the water-soluble, polymer derivatives having a thiol-selective terminus.

Abstract: Provided herein is a straightforward and efficient method for covalently attaching a polyethylene glycol polymer to a taxane. The method involves, among other things, a step of reacting a taxame with a polyethylene glycol polymer comprising a functional group reactive with a functional group within said taxane in the presence of a coupling reagent and DPTS. The result of the reacting step is the formation of a polyethylene glycol-taxane conjugate.

Abstract: The present invention provides, among other things, segmented, degradable polymeric reagents suitable for reaction with biologically active agents to form conjugates, the polymeric reagents comprising one or more polymer chains divided or separated by one or more degradable linkages into polymer segments having a molecular weight suitable for renal clearance. The polymeric reagents can have a substantially linear structure, a branched structure, or a multiarm structure. Each structure includes one or more linkages capable of degradation in vivo.

Abstract: The invention provides a method comprising the steps of providing a poly(ethylene glycol) having one terminal hydroxyl group; reacting the terminal hydroxyl group of the poly(ethylene glycol) with di(1-benzotriazolyl)carbonate to form a 1-benzotriazolylcarbonate ester of the poly(ethylene glycol); reacting the 1-benzotriazolylcarbonate ester of the poly(ethylene glycol) with an amino acid to form an amino acid derivative; and reacting the amino acid derivative with a biologically active agent under conditions to form a polymer-active agent conjugate.