Enhancement of Antithrombogenicity by Urokinase Immobilization on the Gelatin-Adsorbed Polyurethane Surface

=Abstract=The porous polyurethane (PU) sheet was impregnated with 5% (wlv) gelatin solution and the fibrinolytic enzyme to promote the antithrombogenicity of artificial ventricle's surface. Urokinase was immobilized on the gelatin-treated surface with 0.45% (wlv) buffered glutaraldehyde solution (pH 7.4). The coagulation time was delayed to 1.2 times in the gelatin-urokinase co-immobilized surface than the nonporous PU control by APTT measurement. By urokinase immobilization, the maximal activities of the enzyme were elongated (from 2 hour to 4 hour). In vitro study shows that the antithrombogenicity was improved after gelatin adsorption and urokinase immobilization on the polyurethane.