Surface modification and antibacterial properties of superelastic Ti-Zr-based alloys for medical application.

To date, significant progress has been achieved in the development of biomedical superelastic Ti-based alloys with high mechanical properties. In view of the high probability of implant-associated infection, an urgent task is to impart bactericidal properties to the material. Herein, advanced superelastic Ti-18Zr-15Nb alloys were surface-etched in a piranha solution, and then Ag nanoparticles were deposited on their surface using a polyol process. This led to the formation of a porous surface layer with a thickness of approximately 100 nm and pore size of less than 20 nm, filled with metallic Ag nanoparticles with an average size of 14 nm. The surface-modified samples showed superior antibacterial activity against E.coli cells. The enhanced bactericidal efficiency is explained by the combination of a higher rate of Ag+ ions release and direct contact of E.coli cells with Ag nanoparticles.