Surface modification of polymeric biomaterials by albumin grafting using h-irradiation

Polymeric biomaterial surfaces were modified by albumin grafting to improve their blood compatibility. Albumin molecules were functionalized by introducing double bonds using glycidyl acrylate. The functionalized albumin was covalently attached to various biomaterial surfaces such as polypropylene, polycarbonate, and poly(vinyl chloride) by h-irradiation. Surface-induced platelet adhesion and thrombus formation on the albumin-grafted surfaces was examined using computer-enhanced video microscopy and scanning electron microscopy. The amount of the grafted albumin was dependent on the h-irradiation dose and the concentration of albumin used for adsorption. The grafted albumin molecules remained on the surface even after exposure to blood for prolonged time periods. This approach was used to graft albumin to polymeric materials of an oxygenator. The albumin grafting resulted in a substantial improvement in blood compatibility as compared to control oxygenators. The covalent grafting of functionalized albumin by h-irradiation obviates the need for premodification of chemically inert polymer surfaces. It is useful for albumin grafting to various biomaterial surfaces.