IMMOBILIZATION OF HUMAN THROMBOMODULIN ONTO POLY(ETHER URETHANE UREA)FOR DEVELOPING ANTITHROMBOGENIC BLOOD-CONTACTING MATERIALS

Thrombomodulin (TM) is a newly described endothelial cell-associated p rotein that functions as a potent natural anticoagulant by converting thrombin from a procoagulant protease to an anticoagulant. In this stu dy, focussing on the application of TM for biomedical materials, recom binant human TM (hTM) was immobilized onto the polymers for medical us e, and the evaluation of their antithrombogenicity and the interaction with platelets were investigated. As the base polymer for immobilizat ion reaction, poly(ether urethane urea)(PEUU), which was reported to h ave good blood compatibility, was used. hTM-immobilized PEUU showed su perior antithrombogenic activity, such as the prolongation of plasma r ecalcification time and the inhibition of thrombin-induced platelet ag gregation, though the amount of immobilized hTM was very small (i.e. l ess than 1 mu g/cm(2)). Platelet adhesions onto hTM-immobilized PEUU w ere not observed. These results show that the immobilization of hTM do es not change the native good blood compatibility of PEUU, but provide s excellent anticoagulant activity.