A photo-thermal dual crosslinked chitosan-based hydrogel membrane for guided bone regeneration

Alveolar bone defects caused by inflammation or trauma jeopardize patients' oral functions. Guided bone regeneration (GBR) is widely used in repairing periodontal tissue, with barrier membranes play a crucial role in preserving the bone regeneration space. In this study, an injectable dual-crosslinked hydrogel was developed to improve the existing barrier membranes in flexibility and functionality. The hydrogel matrix, composed of methacrylated carboxymethyl chitosan (CMCS) reinforced with robust silk fibroin (SF), was further functionalized with bioactive glass (BG) particles to promote bone regeneration. The pre-gel solution achieved a fast-curing process under visible light and at body temperature. Further, the composite hydrogels presented good biocompatibility, biodegradability, resilience, alongside in vitro barrier effect against human gingival fibroblasts (HGFs). It significantly enhanced osteogenic differentiation and angiogenesis of bone marrow mesenchymal stem cells (BMSCs), facilitate the tube formation of human umbilical vein endothelial cells (HUVECs), and inhibit Staphylococcus aureus and Porphyromonas gingivalis. In a rat skull defect model, the osteogenic performance of hydrogels was comparable with that of collagen membranes (Bio-Gide®). Overall, this in-situ gel-forming barrier material served as a stable carrier for bioactive ions and a biomineralized scaffold for tissue ingrowth, supporting the enhancement of GBR technique.