Topography, Corrosion Resistance and Bioactivity of a Cobalt Titanium Dioxide Coating on a Titanium Surface Via Plasma Electrolytic Oxidation

Abstract

Titanium and titanium alloys are widely used to treat orthopedic and dental deficiencies and restorations because of their excellent biocompatibility and mechanical properties. However, they have some drawbacks, such as an inherent biological inertness that prevents them from adhering to cells or tissues, resulting in weak bone induction and angiogenesis abilities. Improving the biological properties of titanium and titanium alloy implants to increase osteogenesis and angiogenesis remains a significant challenge in the field of biomaterials. In addition, the continuous release of various metal ions in the microenvironment caused by body fluid corrosion can also lead to ultimate failure in implanting. Therefore, improving the corrosion resistance of both titanium and titanium alloys is an urgent task. In this study, we prepared cobalt titanium dioxide (Co-TiO2) coatings on medical titanium surfaces using micro arc oxidation. The surface characteristics, chemical composition, and structure of the coatings were analyzed by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The corrosion resistance of the coatings was evaluated using an electrochemical workstation. These results confirmed that plasma electrolytic oxidation technology can be used to prepare cobalt titanium dioxide coatings in cobalt-containing electrolyte solutions successfully. The coating has a porous structure and a rough surface, and cobalt is successfully doped onto the coating surface. In addition, the cobalt titanium dioxide coating improved the corrosion resistance of titanium. In vitro experiments have shown that cobalt titanium dioxide coating can promote the adhesion and proliferation of MC3T3-E1 cells and has good biological activity. Conclusion: Cobalt titanium dioxide coatings can be prepared on medical titanium surfaces through plasma electrolytic oxidation. These coatings have good surface morphology and biological activity, improve the corrosion resistance of medical titanium, and have good clinical application prospects.