HEPARIN-LIKE ANTICOAGULANT ACTIVITY OF SULFONATED POLY(ETHYLENE OXIDE) AND SULFONATED POLY(ETHYLENE OXIDE)-GRAFTED POLYURETHANE

Sulphonated poly(ethylene oxide) (PEO-SO3) and PEO-SO3-grafted polyure thane (PU-PEO-SO3) were prepared by bulk modification and their antico agulant and heparin-like activities were investigated. Anticoagulant a ctivity measured by activated partial thromboplastin time of PU-PEO-SO 3 displayed 2%, whereas that of PEO-SO3 itself reached 14% as compared to free heparin. In addition, the anticoagulant effects of these sulp honated polymers were not due to factor Xa inhibition but mainly throm bin inhibition. From the clotting time measurements using reptilase in stead of thrombin and antithrombin III (AT III), PEO-SO3 and PU-PEO-SO 3 indicated heparin-like activity which represents both prolonged thro mbin time (TT) and normal reptilase time and increased TT in the prese nce of AT III. Thrombin was also neutralized by sulphonated polymers t o a great extent. Therefore, the anticoagulant and heparin-like activi ties of PEG-SO3 and PU-PEO-SO3 seem to contribute to their improved bl ood compatibility.