Adhesive phosphopullulan gel supports bone regeneration with 50% replacement of autologous bone volume in alveolar cleft repair

Alveolar cleft repair traditionally relies on autologous bone grafting, which is limited by donor-site morbidity, graft availability, and displacement. We evaluated the safety and efficacy of a bioresorbable phosphopullulan (PPL) gel for alveolar cleft repair in preclinical models. Biological safety was assessed according to ISO 10993 guidelines, including cytotoxicity, genotoxicity, sensitization, pyrogenicity, irritation, and systemic toxicity. Osteocompatibility and resorption were evaluated using rabbit bone defect and tooth-erupting alveolar cleft models. The PPL gel showed excellent biocompatibility without adverse biological responses. Although small fragments were detected in the lungs under exaggerated implantation conditions, no pulmonary injury or inflammation was observed; distribution was negligible under clinically relevant conditions. In bone implantation models, the PPL gel demonstrated retention of graft materials, osteoconductivity, and progressive bioresorption, supporting sustained bone formation. In the alveolar cleft model, replacing 50% of the autologous bone graft with PPL gel did not show an apparent adverse effect on bone formation or tooth eruption at 4 weeks compared with autologous bone grafting alone. These findings indicate that PPL gel is a safe and promising bone augmentation material that supports bone regeneration and may reduce graft displacement and the amount of autologous bone required, warranting further translational investigation.