Adhesive Hydrogel Loaded with Sulfonated Chitosan Promotes Oral Mucosal Defect Repair in Diabetic Rats

Diabetic oral mucosal wounds exhibit impaired healing and require biomaterials with strong wet adhesion, favorable biocompatibility, and adequate mechanical stability. In this study, an in situ photocurable adhesive hydrogel (ATDS) based on sulfonated chitosan was developed for diabetic oral mucosal wound repair. ATDS exhibited a tensile strength of 50 kPa, an elongation at break of 320%, and an adhesive strength of 0.605 MPa, while also displaying a porous microstructure without obvious cytotoxicity. Compared with hyaluronic acid (HA) gel, which was completely lost by day 3, ATDS provided more durable wound coverage in the oral environment. In a diabetic rat model of oral mucosal defect, ATDS significantly accelerated wound closure, with wounds nearly completely healed by day 6, promoted re-epithelialization as early as day 3, and increased epidermis thickness by approximately 50% compared with the control group. In addition, ATDS enhanced angiogenesis and reduced the expression of the inflammatory cytokines TNF-α and IL-1β. Collectively, these findings demonstrate that ATDS effectively promotes diabetic oral mucosal wound healing through its barrier-protective, pro-angiogenic, and anti-inflammatory effects, highlighting its potential as a promising biomaterial for oral tissue engineering and regenerative applications.