Abstract: A blood-compatible polyurethane surface was prepared by multiply steps surface modification. ε-Lysine was conjugated to polyurethane surface through PEG spacer via Schiff-base and reduce reaction. The results of water contact angle and XPS measurements suggest that both PEG and lysine are immobilized to the surface successfully. Protein adsorption and plasma clot lysis measurements were performed to investigate the bloodcompatibility of the modified surface. Comparing with the unmodified surface, ε-lysine modified surface reduced fibrinogen adsorption by 80%. It was shown in clot lysis experiment that the ε-lysine modified surface could break down the incipient fibrinous clot within 13 min. The results demonstrate that ε-lysine modified surface not only suppress non-specific protein adsorption, but also degrade fibrin in an evolving clot.

Key words: Polyurethane, Poly(ethylene glycol), Lysine, Protein adsorption resistance, Surface modification, Clot lysis, Bloodcompatibility