Quinone-mediated, tissue-adaptive double-network hydrogel for instant hemostasis and wet-tissue adhesion.

Rapid control of bleeding in complex wounds remains a major clinical challenge. Here, we develop a tissue-adaptive double-network hydrogel that enables instant adhesion to wet tissue and rapid hemostasis. We show that the material can be applied either as an injectable sealant for confined sites or as a conformal patch for large defects. The hydrogel is formed from interpenetrating polymer networks dynamically crosslinked to provide mechanical toughness, rapid self-healing, and shear-thinning injectability. We demonstrate that partial oxidation of catechol groups generates reactive quinone species that form strong bonds with wet tissue without additional activation steps, while incorporated polyphenols accelerate blood clotting. We show that the hydrogel achieves hemostasis within seconds in a mouse liver hemorrhage model and effectively controls bleeding in large-area liver and spleen injuries in rabbits. Finally, we test in a skin incision model to demonstrate that the hydrogel can function as a suture-free adhesive and support healing with minimal scarring.