Construction of a Ni(OH)@CaTiO heterostructure on a Ti implant for enhanced osseointegration through NIR photoactivated bacterial inactivation and microenvironment optimization.

Desirable antibacterial and osseointegration abilities are essentially important for long-term survival of a Ti-orthopedic implant. Herein, a near-infrared light (NIR) excited antibacterial platform with excellent osseointegration composed of perovskite calcium titanate/nickel hydroxide on a Ti implant (Ni(OH)@CaTiO/Ti) was designed and successfully fabricated. The construction of the heterostructure efficiently separated the photogenerated electron-hole pairs to produce sufficient reactive oxygen species (ROS), which enabled the photoactivated bacterial inactivation (PBI) of Ti implants. The results showed that the surface-modified Ti implant displayed remarkable antibacterial ability with bacterial inhibition rates of 95.5% for and 93.8% for under NIR excitation. Also, the intervention of Ni(OH) could create a slightly alkaline surface on the Ti implant, which synchronized with Ca-rich CaTiO to regulate the osteogenic microenvironment in favor of the adhesion, proliferation and differentiation of MC3T3-E1 cells as well as the up-regulation of osteogenesis-related gene expressions. The implantation experiments further confirmed that the heterostructured coating prominently accelerated the formation of new bone and promoted the osseointegration of Ti implants. Our work may provide a novel concept for improving the antibacterial and osseointegration abilities of Ti implants in orthopedic and dental applications.