A nanochitin-drived natural biological adhesive with high cohesive for wound healing.

The weak cohesive strength of tissue adhesives hinders their practical applications. To overcome this challenge, we develop a green bio-adhesive that balances both cohesion and adhesion, drawing inspiration from the natural adhesion mechanisms of mussels. This bio-adhesive, referred to as OTS, was ingeniously crafted through the co-assembly of multi-surface-charged chitin nanofibers (OAChN) and tannic acid (TA), integrated with silk fibroin (SF), resulting in a material with enhanced cohesive strength and robust adhesive properties. The adhesive achieved significant cohesion through hydrogen-bonded crosslinking among OAChN, SF, and TA, boasting a tensile strength of 24.53 KPa and allowing for 150 % elastic deformation. OTS adheres effectively to diverse complex surfaces, with adhesive strengths of 14.55 MPa underwater and 8.83 MPa in air, demonstrating excellent versatility. The biocompatibility and degradability of OTS were confirmed by a wound healing model in SD rats, showing no nanotoxicity and effectively promoting wound healing, rapid hemostasis, and sealing. This green adhesive strategy offers a novel approach to augmenting the cohesive strength of tissue adhesives suitable for complex conditions and has potential medical applications ranging from rapid hemostasis to wound healing enhancement.