A Biomimicking Non-Swelling Wet Tissue Adhesive With Instant, Tough, and Durable Adhesion for Wound Closure

Durable tough underwater tissue adhesion presents a big challenge due to the inherent materials science trade-off between robust interfacial bonding and cohesion strength. Inspired by the synergistic adhesion mechanisms of mussel foot proteins and barnacle cement proteins, we designed and synthesized a novel adhesive via UV-initiated copolymerization of four acrylate monomers: a long-chain alkyl catechol derivative (Cd), its phenolic analogue (Cs), hydroxyethyl acrylate (HEA), and dimethylaminoethyl methacrylate (DMA). Its adhesion is water-triggered, fast (<1 min), tough (underwater tissue adhesion strength: ∼388 kPa; interfacial toughness: ∼530 J/m²), due to the strong interfacial interactions at the adhesive/adherend interface, and the good energy dissipation capacity from the high cohesive mechanical properties (stress: 724 kPa, strain: 395%, and toughness: 864 kJ/m³). Moreover, its adhesion strength to underwater tissue is durable for up to 14 d, attributable to its non-swelling properties (water adsorption ratio is just ∼4%). It can effectively close tissue incisions and facilitate wound healing. This study elucidates the influence of catechol groups, cationic moiety, and hydrophobic segments on underwater adhesion, and therefore develops a non-swellable wet tissue adhesive for better serving the clinical needs.