Nano Sim@ZIF8@PDA modified injectable temperature sensitive nanocomposite hydrogel for photothermal/drug therapy for peri-implantitis.

Dental implant restoration has become one of the most important treatments for missing teeth. However, peri-implantitis is a common complication of implant restorations, and lack of timely and effective treatment will most likely lead to implant failure. Here, we developed a chitosan-based multifunctional temperature-sensitive hydrogel. Chitosan (CS)/β-glycerophosphate (β-GP) as the body of the hydrogel enabled a gelation transition at physiological temperatures. To enhance functionality, we designed Sim@ZIF8@PDA nanoparticles (SZP), where simvastatin (Sim) was loaded onto the zeolitic imidazolate framework-8 (ZIF8), leveraging its high drug-loading capacity and pH-sensitive release properties. These nanoparticles were further coated with polydopamine (PDA) to enhance photothermal efficiency and stability. The SZP nanoparticles were subsequently integrated with CS/β-GP to form the SZP/CS/β-GP hydrogel. The results showed that under near-infrared light irradiation, PDA exerted a photothermal effect to achieve anti-infection, while the release of simvastatin could promote the differentiation of CD4+ T cells to regulatory T cells (Tregs) to achieve immunoregulation. SZP/CS/β-GP hydrogel attenuated the infection and inflammation at the peri-implantitis lesion. In conclusion, this study provides a new approach for the non-surgical treatment of peri-implantitis.