Long-term antibacterial characteristics and cytocompatibility of titania nanotubes loaded with Au nanoparticles without photocatalytic effects

Au nanoparticles (NPs) can endow titania nanotubes (Au@TiO₂-NT) with light-independent antibacterial properties which bode well for in vivo application because of the dark environment inside tissues. In this work, the long-term antibacterial bactericidal properties and cytocompatibility of Au@TiO₂-NT without photocatalytic effects are studied in details. The materials exhibit MC3T3-E1 osteoblasts on Au@TiO₂-NT reveal cytocompatibility comparable to that of TiO₂-NT. No reactive oxygen species (ROS) are detected from either the antibacterial effects against Staphylococcus aureus according to antibacterial tests carried out for a total time of 21 days, which are normally long enough for early stage tissue healing after surgery. In addition, adhesion and proliferation of bacteria or MC3T3-E1 cells cultured on the Au@TiO₂-NT surface. The absence of ROS, long-term antibacterial properties, and cytocompatibility make Au@TiO₂-NT promising biomaterials in orthopedic devices and implants.