Well-defined polymers with activated ester and protected aldehyde side chains for bio-functionalization

Polymers with reactive side chains and narrow molecular weight distributions were synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization, and the potential to utilize these polymers to prepare drug carriers was demonstrated. p-Nitrophenyl methacrylate (NPMA) and diethoxypropyl methacrylate (DEPMA) were polymerized utilizing cumyl dithiobenzoate (CDB) as the chain transfer agent and azobisisobutyronitrile (AIBN) as the initiator to high conversions (>= 86%). The resulting pNPMA and pDEPMA had narrow molecular weight distributions (polydispersity indices < 1.3). The ability to functionalize these polymers was confirmed. For pNPMA, up to 86% of the side chains were substituted with the amino acid, glycine methyl ester. The side chains of pDEPMA were hydrolyzed to aldehydes and reaction with O-benzylhydroxylamine and O-methylhydroxylamine to form stable oxime bond conjugates was demonstrated. The percent substitution depended on the feed ratios. Conjugation of an aminooxyfunctionalized RGD peptide was also demonstrated. (c) 2007 Elsevier B.V All rights reserved.