Improvement in antibacterial ability and cell cytotoxicity of Ti-Cu alloy by anodic oxidation

Ti-Cu alloy has potential to be used in plastic surgery and dental implants due to its strong antibacterial properties, high strength and good corrosion resistance. In this paper, Ti-5Cu was anodic-oxidized to enhance the surface compatibility. The influence of the oxidation on the corrosion resistance, antibacterial properties and biological properties was investigated. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) results showed that a double-layer oxide coating with dense inner layer and porous outside layer was formed on Ti-Cu sample. The oxide coating consisted mainly of TiO2, Cu2O and small amount of CuO, improved the corrosion resistance of Ti-Cu alloy by one order of magnitude due to the formation of the dense oxide inner layer, but high Cu ion release was detected. The plate count results showed that the antibacterial activity of Ti-Cu sample was improved to >= 99% due to the comprehensive function of CuO and Cu2O in the coating and Cu2+ release. Cell test results showed that the coating exhibited good cell compatibility, the porous surface structure improved the adhesion of cells, and Cu ion release promoted the cell proliferation.