Study on the Promotion of Healing of Rabbit Dental Extraction Wounds After Bisphosphonate Injection by Slow-Release bFGF from Chitosan Hydrogel.

The increasing use of bisphosphonates (BPs) poses a formidable challenge to the treatment of medication-related osteonecrosis of the jaw (MRONJ), for which effective therapeutic approaches remain scarce to date. This study introduces a chitosan-based thermosensitive composite hydrogel system (CS-bFGF) loaded with basic fibroblast growth factor (bFGF), which is engineered to accelerate the healing of tooth extraction sockets in rabbits following zoledronic acid administration. The CS-bFGF hydrogel underwent comprehensive characterization, with particular emphasis on its microstructural properties. Furthermore, in vitro cytotoxicity assays demonstrated that CS-bFGF exhibited excellent cytocompatibility with no apparent cytotoxicity toward MC3T3-E1 pre-osteoblasts. The healing efficacy was evaluated at 3 months post-implantation of CS-bFGF into the tooth extraction sockets of zoledronic acid-treated rabbits. Gross examination and histological assessment indicated that CS-bFGF treatment significantly reduced the extent of osteonecrosis and inflammatory infiltration in the MRONJ animal model, while markedly enhancing new bone formation. These findings indicate that CS-bFGF holds substantial potential as a therapeutic agent for the management of MRONJ.