Simultaneous incorporation of gallium oxide and tantalum microparticles into micro-arc oxidation coating of titanium possessing antibacterial effect and stimulating cellular response

Orthopedic implants with both osteogenesis and antibacterial functions are particularly promising for bone repair and substitutes. In this study, a micro-arc oxidation (MAO) coating containing titanium dioxide (TiO2), gallium oxide (Ga2O3) and tantalum oxide (Ta2O5) on the titanium surface (MGT) was fabricated by dispersing Ga2O3 and Ta microparticles in the electrolyte. The results showed that the simultaneous incorporation of Ga2O3 and Ta microparticles into the MAO coating resulted in optimized surface performance (e.g., micro-topography, roughness, wettability, surface energy, and protein absorption) of MGT compared with pure titanium (pTi). In addition, MGT exhibited outstanding corrosion resistance owing to the presence of both Ga2O3 and Ta microparticles, which exhibit excellent corrosion resistance and their microparticles were incorporated into the micropores of the coating. Moreover, MGT with good cytocompatibility and optimized surface resulted in improved cellular responses (e.g., proliferation and osteogenic differentiation) of rat bone mesenchymal stem cells, which was attributed to Ta microparticles with outstanding osteogenic bioactivity. Furthermore, the excellent antibacterial effect of MGT was attributed to the slow release of Ga3+ from the coating. Thus, the simultaneous incorporation of Ga2O3 and Ta microparticles into the MAO coating of MGT exhibited excellent cytocompatibility, osteogenic bioactivity, antibacterial functions, and corrosion resistance, suggesting that MGT possesses great potential for bone repair applications.