Multifaceted Ag-alloyed α-Ta5Si3 nanostructured coating for high-performing bioimplants

Abstract

With the growth of the elderly population worldwide especially in developed countries, bioimplants with a multifunctional surface that embraces self-sterilizing trait, biocompatibility with mammalian cells, favorable bioactivities and high wear/corrosion resistance are in acute need. To meet such demand, the Ag-containing nanostructured α-Ta 5 Si 3 coating was fabricated onto Ti6Al4V alloy via double cathode glow discharge method. The effect of Ag addition on the mechanical properties of α-Ta 5 Si 3 was analyzed using first-principles calculations. The as-deposited α-(Ta 0.85 Ag 0.15 ) 5 Si 3 coatings consist of equiaxed nanocrystallites and greatly enhance the surface hardness of Ti6Al4V alloy. Moreover, the electrochemical characteristic, apatite-inducing ability, biocompatibility and antimicrobial trait of the α-(Ta 0.85 Ag 0.15 ) 5 Si 3 coatings were systematically studied for potential orthopedic application. The new coatings were found to remarkably reduce the corrosion damage of Ti6Al4V alloy in Ringer's solution. The coatings also promoted the formation of bone-like apatite layers and have a beneficial effect on MC3T3-E1 cells functions, including adhesion, spreading and proliferation. Ag alloying markedly increased the antibacterial capacity of the α-Ta 5 Si 3 coating against both Escherichia coli ( E. coli ) and Staphylococcus aureus ( S. aureus ) strains, and the released Ag ions were found to enhance antibacterial performance. Therefore, a unique combination of diverse functional traits makes Ag-alloyed α-Ta 5 Si 3 coating an attractive choice in the design of next-generation biomedical implants for aging population. • The (Ta 0.85 Ag 0.15 ) 5 Si 3 coating improves biocorrosion resistance of Ti-6Al-4 V alloy. • Ag addition enables the antibacterial activities of the coating against both E. coli and S. aureus . • The (Ta 0.85 Ag 0.15 ) 5 Si 3 coating enhances the cytocompatibility and in vitro bioactivity of Ti-6Al-4V alloy. • Ag ion release plays a major role in the antibacterial performance of the coating.