Antibacterial, angiogenic, and osteogenic activities of Ca, P, Co, F, and Sr compound doped titania coatings with different Sr content.

Titanium implants are often combined with microporous titania coatings simultaneously doped with various elements to enhance their antibacterial, angiogenic and osteogenic activities. To evaluate how Sr doping levels affect properties of titania coatings simultaneously doped with Ca, P, Co and F (TiCPCF coatings), we prepared coatings with Sr contents equal to 6, 11 and 18 wt% (TiCPCF-S6, TiCPCF-S11 and TiCPCF-S18, respectively) using micro-arc oxidation of titanium. Sr presence in TiCPCF coatings did not affect their phase compositions, microstructure, surface wettability, roughness, and adhesion to titanium. Antibacterial, angio- and osteo-genic activities of all the coatings were evaluated. Sr incorporation improved mesenchymal stem cell proliferation, osteogenic differentiation and implant osseointegration. TiCPCF-S11 showed the most optimum Sr content judging by its enhanced osteogenic activity. While Sr incorporation did not weaken angiogenic and antibacterial abilities of TiCPCF. Thus TiCPCF-S11 coating is a very strong candidate to be used as a next-generation bone implant material.