Surface stabilization treatment enhances initial cell viability and adhesion for biodegradable zinc alloys

Zinc-based alloys hold promise as next generation biodegradable implants. Although zinc implants exhibit excellent biocompatibility in vivo, they have been found to inhibit cell attachment and viability under in vitro conditions. In order to clarify the cell response disparity and improve the biocompatibility of zinc implant materials, Zn-1Mg and Zn-1Mg-0.5Ca alloys underwent surface stabilization treatment in cell culture medium. Surface processing resulted in a stable surface oxide film of ∼300 nm thickness. The stability of the oxide layer substantially increased the viability of cells in both direct and indirect contact assays. It is consequently believed that the surface film characteristics of zinc implants may be an important determinant of biocompatibility.