Surface Characterization of Amorphous Zr-Al-(Ni, Cu) Alloys Immersed in Cell-Culture Medium

Abstract

For the evaluation of zirconium-base amorphous alloys as biomaterials, the surface compositions of amorphous Zr–Al–Ni–Cu and Zr–Al–Cu alloys were characterized using X-ray photoelectron spectroscopy. The alloys were polished, autoclaved, and immersed in Hanks’ solution or Eagle’s minimum essential medium containing fetal bovine serum, MEM+FBS. Aluminum was enriched in the surface oxide film and the substrate just under the film of the alloys polished in water. After autoclaving, aluminum and copper were enriched in the substrate while zirconium was preferentially oxidized and incorporated into the surface oxide film. In Hanks’ solution, copper and nickel decreased in the substrate and surface oxide film, resulting in the enrichment of aluminum in the substrate. In MEM+FBS, zirconium preferentially decreased by the effects of amino acids and proteins while copper was enriched in the substrate. The surface composition of zirconium-base amorphous alloys was much influenced by amino acids and proteins in MEM+FBS.