Cytocompatibility and antimicrobial properties of silver nanoparticle-decorated hydroxyapatite-coated TiMoNbTa alloy

Titanium and its alloys are widely used for implants, although they have limitations like higher elastic modulus compared to bone, causing stress shielding and potential implant failure. To address these issues, β-Ti alloys and calcium phosphate coatings are being developed to improve the mechanical properties while enhancing bone integration. The risk of infection is another important limitation that can be addressed through the deposition of antibacterial and antibiofilm coatings on the alloys. Here, we present a β-Ti alloy (Ti-18Mo-6Nb-5Ta (wt%)) coated with calcium-deficient hydroxyapatite (CDHA) and decorated with silver nanoparticles intended to be used as antimicrobial orthopedic implants. The experiments revealed that human osteoblasts were able to adhere and proliferate on coating. The presence of silver nanoparticles did not adversely affect human osteoblast differentiation and led to a 50% increase in type I collagen production. The coating decorated with silver nanoparticles exhibited a significant antibacterial effect against Staphylococcus aureus , reducing biofilm formation by over 40% after 24 h compared to the undecorated coating. Taken together, these results show the effectiveness of the silver decorated CDHA coating in enhancing osteoblasts proliferation and differentiation while also reducing biofilm growth when compared to CDHA coating.