Biological Properties of an Heparin-Poly (Methyl Methacrylate) Copolymer

The heparin-poly(methyl methacrylate) copolymer was prepared by polymerization of methyl methacrylate on an heparin radical. It was initiated by cerium IV ions and heparin in nitric aqueous solution.An heparin effect was present in the plasma in contact with the copolymer. It was not due to a release of heparin in the plasma, but to a contact effect. The anticoagulant effect was depending upon the concentration of the copolymer. The activity of clotting factors in plasma, after a contact with the copolymer was not decreased except for factor V. Antithrombin III was selectively adsorbed on the surface of the copolymer.The copolymer lost progressively its anticoagulant properties after each contact with the plasma. This might be due to the adsorption of fibrinogen on the copolymer. Labelled 125I albumin, transferrin, Ig G and fibrinogen were not similarly desorbed in the presence of serum and of plasma.This copolymer seems to offer interesting properties for blood devices.