Construction of a TiO2/Cu2O multifunctional coating on Ti-Cu alloy and its influence on the cell compatibility and antibacterial properties

Inflammation and infection caused by implants are serious problems in the clinical application of titanium and titanium alloy. Titanium copper alloy has shown strong antibacterial properties, but the surface bioactivity is still necessary to be modification to improve biocompatibility. In this paper, a TiO2/Cu2O multifunctional coating was prepared on Ti-5Cu alloy by an anodic oxidation process in order to enhance the surface bioactivity without affecting the antibacterial ability. The surface physical and chemical properties of the anodized Ti-Cu alloys were tested by X-ray diffraction (XRD), X-ray photo-electron spectroscopy (XPS), scanning electron microscopy (SEM), Vickers hardness tester, contact angle tester and laser confocal microscope, and the corrosion properties were studied by inductively coupled plasma mass spectrometer and electrochemical workstation. The results have shown that the roughness, the hydrophilicity, the copper ion release the corrosion resistance were increased by the anodization in a voltage dependent way. The effect of the anodization was evaluated on the antibacterial properties and cell bioactivity. It was shown that pure titanium did not have antibacterial properties after the anodization. However, the anodization significantly improved the antibacterial properties of titanium copper alloy due to the formation of TiO2/Cu2O coating. No cytotoxicity was found on Ti-5Cu alloys and the anodized Ti-5Cu alloys but the treatment accelerated the cell adhesion. It was suggested that anodization treatment might be a potential surface biomodification method for the clinical application of titanium copper alloys.