Near-infrared light triggered multi-mode synergetic therapy for improving antibacterial and osteogenic activity of titanium implants

Reducing bacterial infection and improving osseointegration are critical for the long-term use of orthopedic implants, especially for the infection related surgery. Here, mesoporous dopamine (MPDA) nanoparticles were loaded with nitric oxide (NO) donor, S-nitrosoglutathione (GSNO), and they were immobilized on the surface of titanium (Ti). When bacterial infections occurred, a large amount of NO was rapidly released and triggered by the thermal effect of MPDA after the near-infrared (NIR) light irradiation, which could damage the permeability and integrity of the bacterial membrane, leading to the leakage of bacterial DNA, proteins and ATP. Thus, bacteria was synergistically eliminated by NO and photothermal therapy (PTT) under NIR irradiation. While without NIR irradiation, the low concentration of NO was slowly released into the environment from GSNO, which promoted the proliferation and differentiation of osteoblasts. In addition, the in vivo results also demonstrated good osteogenic and antibacterial effects. Therefore, this study demonstrated a multi-mode synergetic therapy for promoting the antibacterial property and osseointegration of titanium implants.