Long-lasting bactericidal activity through selective physical puncture and controlled ions release of polydopamine and silver nanoparticles-loaded TiO nanorods in vitro and in vivo.

Titanium (Ti) implant-associated infection, which is mostly caused by bacterial adhesion and biofilm formation, may result in implant failure and secondary surgery. Thus it is an urgent issue to prevent bacterial infections at the earliest step. To develop a novel surface strategy of polydopamine (PDA) and silver (Ag) nanoparticle-loaded TiO nanorods (NRDs) coatings on Ti alloy. Ag-TiO@PDA NRDs was fabricated on Ti alloy by hydrothermal synthesis. The antibacterial activity of Ag-TiO@PDA NRDs against and methicillin-resistant were tested by FE-SEM, Live/Dead staining, zone of inhibition, bacteria counting method and protein leakage analysis . In addition, an implant infection model was conducted and the samples were tested by X-ray, Micro-CT and histological analysis . Besides, cell morphology and cytotoxicity of Mouse calvarial cells (MC3T3-E1) were characterized by FE-SEM, immunofluorescence and CCK-8 test . Our study successfully developed a new surface coating of Ag-TiO@PDA NRDs. The selective physical puncture of bacteria and controlled release of Ag+ ions of Ag-TiO@PDA NRDs achieved a long-lasting bactericidal ability and anti-biofilm activity with satisfied biocompatibility. This strategy may be promising for clinical applications to reduce the occurrence of infection in the implant surgeries.