An injectable, robust double network adhesive hydrogel for efficient, real-time hemostatic sealing

Despite significant progress in bioadhesive hydrogels, achieving injectable adhesives with robust mechanical strength, strong wet-tissue adhesion and anti-postoperative tissue adhesion is challenging. Herein, an injectable double network adhesive hydrogel (DNAH) consisting of catechol-branched polyacrylamide network formed by radical polymerization and chitosan-oxidized hyaluronic acid covalent network produced by Schiff base condensation is reported. Benefiting from the catechol groups, chemically crosslinked network, a tough dissipative matrix, as well as dynamic oxidation of catechol to quinone, DNAH exhibits high mechanical strength, robust wet-adhesiveness, and postoperative anti-adhesion after injection. Combining the above ideal features with their good injectability and shape-adaptability to complex wound contours, DNAH can coagulate instantaneously in situ and firmly glue to the tissue surface to seal the wounds in rat models of cardiac penetration holes and portal vein injuries, achieving efficient hemostasis. Overall, DNAH developed in this work is demonstrated to be a promising candidate for rapid hemostasis in clinic.