Antibacterial capability of microstripe structure on silver-doped Ti6Al4V by laser interference direct writing.

The antibacterial ability of medical titanium alloy implant in vivo remains a significant challenge for orthopedic implants despite its excellent mechanical and osteoconductive properties. Here, we explored a simple method to improve the antibacterial ability of Ti6Al4V. The silver physically adheres to the surface of the structure by laser interference direct writing after coating the silver film by ion sputtering from 50 to 500 nm; meanwhile, periodic microstripe structure was formed, showing good antibacterial properties against the Gram-positive bacterial Staphylococcus aureus (S. aureus). Moreover, the antibacterial ability was increased with the increase of silver film thickness. While the silver film thickness was larger than 100 nm, the antibacterial rate exceeded 90%. In addition, the Ag⁺ releases concentration for Ag_100nm, Ag_300nm, and Ag_500nm were also measured from 24 to 120 h, which showed the linear increment with the thickness of Ag thin film and release time. The surface of the structure showed the good bio-compatibility for the MC3T3-E1 cell; simultaneously, the growth of the cell was obviously adjusted by these microstripes. In summary, the Ti6Al4V with these microstripes after Ag modification combines good antimicrobial properties, bio-compatibility and cell growth regulation performance, which showed the potential application as an orthopedic implant in the future. [ABSTRACT FROM AUTHOR]