Mechanochemically reprogrammed porous tantalum with synergistic antibacterial and osteogenic properties for the treatment of infectious bone defects

Infection and poor osseointegration following orthopedic implantation remain significant challenges that can lead to complications, including prosthesis loosening, delayed fracture healing, and even implant failure. Porous tantalum is a game changer in the field of bone implants. In this study, we employed magnetron sputtering technology to modify ZnO particles on the surface of tantalum nanotubes (TaNTs) in porous tantalum, which were mechanochemically reprogrammed to enhance their properties. This approach enabled functionalization without altering the surface microstructure, resulting in the development of a ZnO-modified tantalum nanotube array coating (TaNTs@ZnO) designed to address infection. ZnO coating, applied via magnetron sputtering, exhibits pH-responsive Zn2+ release and antibacterial activity, achieving over 99% inhibition against S. aureus and E. coli by disrupting bacterial membranes and metabolism. Additionally, TaNTs promote bone marrow mesenchymal stem cells (BMSCs) adhesion and osteogenic differentiation, accelerating bone healing and osseointegration in both femoral condyle and infective bone defect models. In conclusion, TaNTs@ZnO show strong antibacterial and osteogenic capabilities, offering a promising solution for bone defect treatment and infection prevention.