Antisera binding onto metals immersed in human plasma in vitro.

Titanium (Ti), silicon (Si), silver (Ag), vanadium (V), gold (Au), and chromium (Cr) surfaces were made hydrophilic by radiofrequency plasma treatment. The binding of antifibrinogen (a-fib) and anti-high-molecular-weight kininogen (a-HMWK) after incubation of surfaces in 10% human blood plasma was investigated with ellipsometry. Ti and Si surfaces bound a-HMWK but no detectable amounts of a-fib, whereas the other metals bound both types of antisera. Protein adsorption in a fluid gradient produced under a convex lens indicated that the small deposition of a-fib on Ti and Si surfaces is probably a result of protein displacement. This displacement was not evident at lens positions simulating low plasma concentrations where large amounts of a-fib adsorbed. Surfaces washed sequentially in trichloroethane, acetone, and ethanol produced more hydrophobic surfaces and resulted in slower rates of a-fib displacement. These studies would indicate that some metals form complexes with specific plasma proteins or, alternatively, that different metals may bind equal amounts of plasma proteins which express differing antigenicities toward their surroundings.