In some aspects, the present disclosure pertains to a radiopaque, reactive polymer comprising one or more hydrophilic polymer segments having a plurality of hydrophilic polymer segment ends, a plurality of iodinated cyclic anhydride residues covalently linked to the plurality of hydrophilic polymer segment ends, and a plurality of reactive moieties covalently linked to the iodinated cyclic anhydride residues. In some aspects, the present disclosure pertains to a system for forming a hydrogel composition that comprises (a) a nucleophilic compound and (b) such a radiopaque, reactive polymer. In some aspects, the present disclosure pertains to a method of treatment comprising administering to a subject a mixture that comprises (a) a nucleophilic compound and (b) such a radiopaque, reactive polymer under conditions such that the nucleophilic compound and the radiopaque, reactive polymer crosslink after administration.

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.

A drug conjugate is provided herein. The conjugate comprises a protein based recognition-molecule (PBRM) and a polymeric carrier substituted with one or more -L.sup.D-D, the protein based recognition-molecule being connected to the polymeric carrier by L.sup.P. Each occurrence of D is independently a therapeutic agent having a molecular weight 5 kDa. L.sup.D and L.sup.P are linkers connecting the therapeutic agent and PBRM to the polymeric carrier respectively. Also disclosed are polymeric scaffolds useful for conjugating with a PBRM to form a polymer-drug-PBRM conjugate described herein, compositions comprising the conjugates, methods of their preparation, and methods of treating various disorders with the conjugates or their compositions.

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.

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.

In some aspects, the present disclosure pertains to a polymer that comprises a plurality of polymeric arms, wherein a first portion of the polymeric arms each comprises a reactive end group and wherein a second portion of the polymeric arms each comprises a radiopaque aromatic moiety comprising a monocyclic or multicyclic aromatic structure having a plurality of radiopaque functional groups and a plurality of hydrophilic functional groups. In some aspects, the present disclosure pertains to systems comprising (a) a first composition comprising such a radiopaque polymer and (b) a second composition comprising a multifunctional compound that comprises reactive functional groups that are reactive with the reactive end group. In some aspects, the present disclosure pertains to crosslinked reaction products of (a) such a radiopaque polymer and (b) a multifunctional compound that comprises reactive functional groups that are reactive with the reactive end group.