Copper-Chelated Thermosensitive Hybrid Hydrogels for Peri-Implantitis Treatment

Peri-implantitis (PI) is a common disease that occurs in most dental implant patients. The progressive bone resorption related to PI markedly affects patients' life quality. Thermosensitive hydrogels composed of chitosan (CS) and β-glycerophosphate (GP) have been previously employed for the PI treatment. However, their restricted mechanical strength undermined the bone-repairing outcome. The formation of a hybrid network by adding inorganic crosslinking components may help improve the mechanical properties of hydrogels. Moreover, copper (Cu) ions have been confirmed to be beneficial for bacterial killing in a concentration-dependent manner. Hence, a copper chelated thermosensitive hybrid hydrogel (Cu/CGT) is fabricated here by incorporating tetraethoxysilane into the Cu doped CS and GP solution. Material characterization, biocompatibility, and antibacterial tests are conducted in vitro and in vivo to determine the physical and biological properties of hydrogels. The result shows that 1Cu/CGT with improved compressive modulus can not only promote the osteogenic differentiation and suppress the inflammation, but also show notable bacterial killing ability against pathogenic bacteria. The ideal Cu release profile of 1Cu/CGT may contribute to the satisfactory biomedical performance of hydrogels. In summary, this study develops a thermosensitive hybrid hydrogel with ideal bacterial-defensive and pro-osteogenic performance, exhibiting good potential for clinical treatment of PI.