Evaluation of the performance of TiO₂ thin films doped with silver nanoparticles as a protective coating for metal prostheses

Metallic alloys are widely used in orthopedic and dental prostheses due to their mechanical stability, hard tissue compatibility, strong resistance to corrosion and biocompatibility. Corrosion may occur once the prosthesis is integrated into the patient due to the presence of natural defects in alloys, which limits their biocompatibility. A promising strategy to prevent corrosion in metallic implants is to grow TiO₂ films on their surface, which act as an extension of the prosthesis to the bone and increase biocompatibility. In addition, silver nanoparticles are well known for their antibacterial properties. In this work, we propose the combination of the biocompatible properties of TiO₂ coatings with the antibacterial activity of metallic silver nanoparticles through their synthesis as thin films on 316 L stainless steel. These coatings were prepared by the sol-gel process, a versatile and low-cost synthetic method. The corrosion resistance of 316 L steel samples coated with these films was evaluated by the linear polarization technique using a simulated body fluid (SBF) electrolyte at 37 °C and pH of 7.25. Our results showed a decrease in the corrosion rate of about 70 % for both coated and non-coated samples. Coated samples were characterized by SEM microscopy. The coating was found to be biocompatible with osteoblast cells and exhibited antifungal activity against Aspergillus flavus.