Bio‐Inspired Self‐Hydrophobized Sericin Adhesive with Tough Underwater Adhesion Enables Wound Healing and Fluid Leakage Sealing

Abstract Given that adhesion‐resistance of water severely weakens the bonding strength of tissue adhesives, instant adhesion to wet biological tissue surfaces remains challenging. Inspired by the robust underwater adhesion of natural creatures (such as mussels and barnacles whose underwater adhesion derives from the synergy of hydrophobic and adhesive matrix), a self‐hydrophobized adhesive is developed by co‐assembly of disulfide‐bond hydrolyzed hydrophobic natural sericin protein (a major component of silkworm silk fibers) and tannic acid. Once exposed to water, the self‐aggregation of hydrophobic chains within the adhesive repels water and enhances interfacial hydrogen bonding or electrostatic interactions, mechanistically leading to a robust (>0.5 MPa for solid plates and >0.1 MPa for tissues) and durable (still maintained at 0.4 Mpa even after five cycles) underwater adhesion. Owing to its robust underwater adhesion property, this adhesive possesses multiple advantages outperforming commercial adhesives, such as in vivo wound healing‐promoting effects, effective fluid leakage sealing, and rapid hemostasis activity. This study not only offers a novel strategy for designing and fabricating an underwater adhesive with natural protein but also provides a new adhesive for various potential applications, including promoting wound healing and hemostasis.