An anti-corrosion MAO coating containing germanium dioxide and tantalum pentoxide on titanium surface for facilitating osteoblastic differentiation and killing bacteria

Looseness and infection are the two main reasons for failure of titanium (Ti) based implants (TBI), and offering TBI with superb osteogenesis and bactericidal effects is especially promising for orthopedic applications. Herein, a micro-arc oxidation (MAO) coating including germanium oxide (GeO2), tantalum oxide (Ta2O5) and titanium dioxide (TiO2) on Ti (MTG) surface was created through simultaneous dispersing Ge and Ta particles in the basic electrolyte. In comparison with Ti, the simultaneous deposition of Ge and Ta particles onto the MAO coating led to the change of surface characters (e.g., topography, hydrophilicity, roughness, and protein absorption) of MTG. Moreover, MTG exhibited exceptional corrosion resistance because of presence of Ta2O5. In addition, MTG significantly facilitated the cell response (e.g., attachment, multiplication, and osteoblastic differentiation) due to the existence of Ta2O5. Further, MTG revealed excellent bactericidal capability, which was ascribed to the sustained-release of Ge ions from the MAO coating. Accordingly, simultaneous deposition of Ge and Ta particles onto the MAO coating resulted in a novel implantable biomaterial of MTG with illustrious osteogenic and antibacterial capability as well as corrosion resistance. In short, MTG with excellent cytocompatibility possessed great potential for dental and load-bearing bone replacements.