Mussel-inspired adhesive drug-loaded hydrogels for oral ulcers treatment

Oral aphthous ulcers are common mucosal lesions that cause pain and discomfort. There are diverse biomaterials and drug treatments for oral ulcers used in both research and clinical settings. However, the complex oral environment often results in low adhesion and short drug retention times, which lead to poor drug availability and treatment outcomes. In this study, a mussel-inspired adhesive hydrogel was developed by grafting catechol onto hyaluronic acid (C-HA), and dopamine was added for oxidative pre-polymerization to form modified hyaluronic acid (M-HA), which remarkably increased the adhesion of the hydrogels. Then, M-HA was interpenetrated into the gelatin methacryloyl (GelMA) network. Chlorhexidine gluconate (CHG) was then incorporated into the hydrogel to enhance its availability and therapeutic effect through its sustained-release capability. The GelMA/M-HA hydrogel demonstrated strong adhesion to wet tissues, antibacterial and anti-inflammatory properties, and good biocompatibility. In both rat oral ulcers and infected wounds, the adhesive hydrogel significantly accelerated the healing of the ulcers and infected wounds. These results indicated that this adhesive hydrogel offers a promising new strategy for the treatment of oral ulcers in clinical practice. STATEMENT OF SIGNIFICANCE: Oral ulcers are a common and high-incidence mucosal condition that seriously affect people's daily lives, often making it difficult for patients to chew and speak. However, a dynamic oral environment with various types of bacteria influences drug availability and treatment effects in clinical settings. To address this challenge, an adhesive, mussel-inspired, drug-loaded hydrogel was constructed using natural macromolecules (hyaluronic acid and gelatin) with good biocompatibility. Chlorhexidine gluconate (CHG), with its broad-spectrum antibacterial activity, has been incorporated to synergistically promote oral ulcer healing. The splendid adhesion, antibacterial, and therapeutic effects of this hydrogel demonstrated a new strategy for treating oral ulcers.