Synthesis and nonthrombogenicity of polymer membrane with surface‐graft polymers carrying thrombin inhibitor

An acrylamide derivative of a thrombin inhibitor was synthesized and graft polymerized to the surfaces of polymer membranes. The thrombin-inhibitor activity was unaffected by the introduction of an acryloyl group. The surface-graft membrane deactivated thrombin markedly and suppressed adhesion of platelets, resulting in a high nonthrombogenicity. Immersion of polymer membranes blended with the thrombin inhibitor in phosphate-buffered saline for 10 d resulted in the loss of nonthrombogenicity, while the polymer membranes grafted with the thrombin inhibitor derivative maintained the nonthrombogenicity over a long period.