Semitelechelic Poly[N-(2-hydroxypropyl)-methacrylamide] for Biomedical Applications

Semitelechelic (ST) polymers are low molecular weight linear macromolecules having a reactive functional group at one end of the polymer chain and one terminal end. To modify proteins or biomedical surfaces by one point attachment, ST polymers should be used. ST polymers with N-hydroxysuccinimide ester end groups ST-poly [N-(2-hydroxypropyl) methacrylamide] (ST-PHPMA)-COOSu were synthesized by esterification of ST-PHPMA-COOH with a large excess of N-HOSu with dicyclohexyl carbodiimide as coupling agent. The modification of charge transfer with narrow fractions of ST (2-hydroxypropyl) methacrylamide (HPMA) polymers produced conjugates possessing a uniform structure compared with those prepared from unfractionated ST macromolecules. ST HPMA polymers also effectively modify biomedical surfaces. The functional ST HPMA polymers can be readily prepared by free radical polymerization in the presence of functional mercaptans. The functional groups and chain length of the ST polymers can be controlled by the choice of a particular mercaptan and the reaction conditions.