Optimization of TiO2 Coatings Properties and Photochemical Ag-functionalization: Implications on Bioactivity and Antibacterial Activity

Titanium-based implants are widely used in implant manufacture. However, the low bone-implant contact and infections are still potential complications. To pursue the development of nanotubular TiO2 coatings that present suitable characteristics for biomedical application, synthesis variables, and Ag-functionalization were explored. TiO2 coatings were grown over Ticp and Ti6Al4V by potentiostatic anodization (25 V, 90 min, 25 °C), being investigated the substrate, %wt NH4F, electrolyte stirring, and annealing effect on biocompatibility and antimicrobial performance. Samples were characterized by FE-SEM, XDR, and contact angle. The results show that morphology and microstructure are very sensitive to these experimental parameters. Stirring was related to an aggressive dissolution. Static condition can be used to grow nanotubes and enhance anatase stabilization, wettability, and apatite epitaxy. The optimized condition was achieved with annealed 0.75-%wt NH4F, without stirring. This condition was photochemically Ag-functionalized in 0.25/0.5 M of AgNO3 and the results demonstrated an increase in the antimicrobial activity.