Fibrinogen adsorption and platelet adhesion to metal and carbon coatings.

In order to study the haemocompatibility of metal and carbon coatings, fibrinogen adsorption and platelet adhesion to various coatings have been investigated. Two metallic coatings--titanium and zirconium, and two carbon coatings - isotropic diamond-like and isotropic graphite-like coatings, were prepared by plasma vapour deposition onto stainless steel substrate. It has been shown that the adsorption of fibrinogen to metal and carbon coatings and its post-adsorptive transition are dependent on both the material properties and the fibrinogen environment. The adsorption of fibrinogen from human plasma on titanium and zirconium coatings is similar to that on uncoated stainless steel surface. Both carbon coatings adsorb much greater amount of fibrinogen from plasma, and fibrinogen retention by carbon surfaces is also greater than by metal surfaces. Increased numbers of adhered platelets have been found on both carbon coatings in comparison to the metal materials, although this does not correlate with the amount of adsorbed fibrinogen.