A Biodegradable, Self-Gelling Protease-Grafted Alginate Dressing for Efficient Control of Non-Compressible Hemorrhage

Uncontrollable noncompressible bleeding has always been a major cause of death and disability among civilians and military personnel. Herein, a biodegradable, self-gelling protease-grafted alginate dressing was developed for efficient noncompressible bleeding control. The hemostatic dressing was fabricated through a high-degree sodium ion exchange of calcium alginate fibers, followed by covalent grafting of trypsin via carbodiimide chemistry. This design confers exceptional swelling capacity and rapid gelation within seconds upon blood contact, forming a physical barrier. The grafted trypsin establishes an artificial coagulation pathway independent of endogenous factors, significantly shortening in vitro clotting times. Moreover, it promotes adhesion and aggregation of red blood cells and platelets, accelerating clot formation and increasing the clot strength. In a rabbit liver injury model, the dressing achieved hemostasis within 70 s, significantly reducing blood loss and promoting wound healing compared to commercial SURGICEL while demonstrating excellent biocompatibility and biodegradability. The protease-grafted alginate dressing exhibited high robustness against high-temperature treatment, maintaining its high procoagulant activity in vitro for over 55 days at 47 °C.