Photocurable robust gelatin-based hydrogel with strong tissue adhesion for wound closure

Traditional wound closure techniques still have many shortcomings, including invasive procedures, foreign body reactions, and suboptimal healing outcomes. An adhesive with high tissue adhesion and robust mechanical properties for wound closure and healing is an urgent need in wound management. This study has successfully designed a photocurable bioadhesive diazirine-modified gelatin (DG), which exhibited good tissue adhesion. Additionally, Gelatin Methacryloyl (GelMA) was incorporated to form dual-network hydrogel Diazirine-Gelatin-Methacryloyl (DGM) with better mechanical properties, thereby achieving strong tissue adhesion. The prepared DGM adhesive has a burst pressure of 324 mmHg and a lap shear strength of 60 kPa. The DGM also has exhibited good biocompatibility in both in vitro and in vivo. In a full-thickness skin incision model, not only was DGM able to provide reliable wound adhesion, it also had healing promotion capabilities compared with traditional sutures and commercial adhesives. During healing process, DGM effectively decreased the inflammation and encouraged the deposition of collagen, which is orderly, and resulting in high-quality tissue healing. This high-performance hydrogel adhesive provides new insights for wound repair. STATEMENT OF SIGNIFICANCE: Developing an ideal wound adhesive that balances interfacial adhesion, bulk mechanical properties and biocompatibility remains a problem. The present work is devoted to solving this problem. This study synthesizes diazirine-modified gelatin (DG) successfully, which can generate strong interfacial adhesion by forming covalent bonds with amino groups on tissue surfaces under UV light (365 nm) irradiation. After introduction of Gelatin Methacryloyl (GelMA), the bulk mechanical properties and fatigue resistance of the adhesive have been enhanced. Thereby achieving reliable wound closure and providing an optimal healing environment for the wound. This work not only creates a promising adhesive for wound management but also provides a versatile chemical strategy for developing next-generation tissue adhesives.