Heparin-conjugated star-shaped PLA for improved biocompatibility

Abstract

Star-shaped PLA-heparin (sPLA-Hep) was prepared by coupling heparin to the star-shaped PLA (sPLA) reaction using carbonyldiimidazole (CDI) chemistry. Hydroxyl groups of sPLA were activated by CDI for the reaction with the remained amino-terminal groups of heparin. The surface heparin content of sPLA-Hep was measured to be 1.43 mu g/cm(2). sPLA-Hep-coated surface has shown higher hydrophilicity than control surface. The clotting time of sPLA-Hep measured by activated partial thromboplastin time (APTT) was significantly prolonged when compared with sPLA and linear PLA-Hep. sPLA-Hep surface demonstrated lower protein adsorption and platelet adhesion than control sPLA surface. In addition, fibroblast culture on the sPLA-Hep surface showed the enhanced cell spreading area compared with the sPLA surface. Obtained results suggest that the incorporation of heparin to sPLA is effective in curtailing the surface induced thrombosis and in manipulating the cell interaction. sPLA-Hep could be applied as blood/tissue compatible biodegradable materials for implantable medical devices and tissue engineering. (c) 2007 Wiley Periodicals, Inc.