Ellipsometric in vitro studies on blood plasma and serum adsorption to zirconium

Ellipsometry/antibody techniques were used to study the adsorption of heparinized human blood plasma and serum onto spontaneously oxidized zirconium, and a colorimetric assay measured the formation of kallikrein by the surface in citrated plasma. After 10 min incubation in the blood plasma the protein film thickness was approximately 4.2 nm, and the film bound polyclonal antibodies mainly against high molecular weight kininogen (HMWK), immunoglobulin G (IgG) and fibrinogen. After 5 or 60 min of incubations in whole normal or EGTA sera, antibodies against complement factor 3 (C3) and complement factor 3d (C3d) deposited to the surface. Factor H and complement factor 1q (C1q) were detected similarly after 1 and 5 min of incubation in 1-10% normal serum in veronal buffer, respectively. The indications are that upon contact with blood plasma, zirconium activates the intrinsic pathway of coagulation and is opsonized with C3. The failure to detect properdin and transient presence of factor H at the surface suggest that complement binds to zirconium although the activation becomes quickly down-regulated.