Facile Fabrication of Poly(N-vinyl pyrrolidone)-Iodine Coating on TiO₂ Nanotubes with Antibacterial and Osteoconductive Properties

Implants made of titanium (Ti) and its alloys are widely used in orthopedics and dentistry. However, the Ti-based materials, due to their inherent surface bioinertness, lack antibacterial properties and osteoconductive activity, leading to an increased risk of bacterial infection post-implantation and suboptimal osseointegration efficiency. Herein, an antibacterial and osteoconductive coating via polydopamineassisted immobilization of poly(N-vinyl pyrrolidone)-iodine (PVP-I) on TiO₂ nanotubes named TNT-DP-I is constructed. The TNT-DP-I coating could rapidly kill 97.80% Gram-positive Staphylococcus aureus (S. aureus) and 97.96% Gram-negative Escherichia coli (E. coli) within 1 h, highlighting its superior antibacterial efficiency. Additionally, this coating effectively promoted pre-osteoblasts MC3T3-E1 adhesion, growth, and proliferation, demonstrating enhanced osteoconductivity. Meanwhile, TNT-DP-I coating demonstrated good mammalian cytocompatibility and hemocompatibility, suggesting its promising biosafety. Overall, this study presents a facile approach for reducing bacterial contamination and enhancing osseointegration of Ti implants.