Multifunctional bioactive coating on biomedical -Ti12Mo6Zr2Fe alloy to improve corrosion protection and bioactivity properties

The present work presents and discusses the results of a comprehensive electrochemical study of the laser-textured beta-Ti12Mo6Zr2Fe (TMZF) alloy coated with a bioactive layer (TMZF-BL), which was strategically designed to produce an improvement in corrosion resistance and impart bioactive properties to the TMZF alloy. The bioactivation of the laser-textured TMZF alloy was performed using a simple and innovative strategy that effectively coated the metal surface with a bioactive layer structured with bioactive glass (BG) particles functionalized with silicate and phosphate groups, acting as chemical anchoring agents. The electrochemical corrosion behavior of the bare and coated TMZF was evaluated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) in Simulated Body Fluid (SBF) at 37 degree celsius. Our results showed that the presence of the bioactive layer in the TMZF-BL samples shifted the corrosion potential (E-corr) towards more noble values compared to polished TMZF (TMZF-P), and increased EIS modulus, suggesting that the corrosion resistance improved. The chemical stability of the bioactive coating was confirmed by the high polarization resistance and low capacitance values. Various analysis techniques surveyed the apatite-forming ability and growth on the surface of TMZF-P and TMZF-BL alloys as a function of soaking time in SBF. The bone-like apatite formation rate depended on the homogeneity of the bioactive layer covering the surface of the TMZF-BL alloy. Taken together, our results confirm the success of the experimental strategy designed to bioactivate the TMZF alloy and reinforce the potential of this approach for the development of highly stable bioactive implants, in addition to protecting the alloy surface against corrosion in the physiological environment.