Synergistic antibacterial photocatalytic and photothermal properties over bowl-shaped TiO2 nanostructures on Ti-19Zr-10Nb-1Fe alloy

As implant substitutes are increasingly applied to the clinic, the infection caused by implants has become one of the most common complications, and the modification of the antibacterial function of the implant can reduce such complications. In this work, a well-defined bowl-shaped nanostructure coating with photocatalytic and photothermal synergistic antibacterial properties was prepared on Ti-19Zr-10Nb-1Fe (TZNF) alloy. The coating is obtained by spin-coating and sintering TiO2 precursors templated from self-assembled microspheres of polystyrene-poly(4-vinylpyridine) (PS-P4VP) amphiphilic block polymer on TZNF alloy. PS-P4VP provides the bowl-shaped TiO2 nanostructures doped with C, N elements, reducing the band-gap of TiO2, which can absorb near-infrared (NIR) light to release reactive oxygen species and produce photothermal conversion. The bowl structure is expected to enhance the utilization of light via the reflection in the confined space. The bowl-shaped surface has 100% antibacterial rates after 30 min of NIR light irradiation. In addition to antibacterial properties, the bowl-shaped surface has better hydrophilicity and protein adsorption capacity. The amount of protein adsorbed on TZNF with the bowl-shaped structures was six times that of TZNF. Hence, the bowl-shaped nanostructure can promote the proliferation and adhesion of osteoblasts, the cell proliferation rate was increased by 10-30%.