Surface Hemocompatibility of Three Biomedical Carbonaceous Materials

Surface hemocompatibilities of graphite, diamond-film and diamond-like coating were investigated by comparing the surface energy parameters with the conformation changes of plasma-proteins and platelets on the surfaces of these materials. It is shown that graphite has the highest critical surface-tension and interfacial free-energy, followed by diamond-film and diamond-like coating, but in a reverse order are the magnitudes of γ_s~p/γ_s~d of three materials. Among the three materials, graphite has most significant effect on the conformation of plasma-protein, then diamond-film and, finally, the diamond-like coating. The platelets adhered on the surface of graphite are much more than those on the diamond-film, while on the surface of diamond-like coating, nearly no platelets are founded. It follows that the surface hemocompatibility of diamond-like coating is the best among the three materials.