Abstract: Gelatin was covalently immobilized onto the polyurethane membrane surface grafted previously with poly(methacrylic acid) (PU-g-PMAA) using 1-[(3-dimethylamino)propyl]-3-ethyl carbodiimide as the condensing reagent. ATR-FTIR and ESCAcharacterizations verify the occurrence of the grafting, and prove that the immobilized amount of gelatin is proportional to the number of active sites, i.e. carboxylic groups on PU surface. Endothelial cells culture reveals that the cell attachment and cell growth on PU-g-PMAA-g-Gelatin are both improved obviously, demonstrating that a cell compatible PUis obtained and the immobilizing method is quite effective to introduce cell growth factors onto polymer surface.

Key words: Polyurethane, Gelatin, Coupling, Endothelial cell, Cytocompatibility