Gelable and Adhesive Powder for Lethal Non‐Compressible Hemorrhage Control

Hemostatic powders are widely used in clinical and emergency situations but often exhibit low wet adhesion, cytotoxicity concerns, and do not work well for lethal non‐compressible hemorrhage. Here a new kind of gelable and adhesive powder (GAP) is developed, which integrates chitosan microspheres (CM), tetra‐armed poly(ethylene glycol) amine (Tetra‐PEG‐NH 2 ), and tetra‐armed poly(ethylene glycol) succinimidyl succinate (Tetra‐PEG‐SS). Upon application to the wound site, the macroporous CM can rapidly absorb the interfacial liquids, and meanwhile, the hydrated GAP turns into hydrogel (crosslinking between Tetra‐PEG‐SS and CM/Tetra‐PEG‐NH 2 ) with stable and robust adhesion to the wet tissue though covalent bonding. The in vitro and in vivo results suggest that the GAP with optimized formulation exhibits strong tissue adhesive, high burst pressure, and enhanced blood clotting ability, as well as excellent biocompatibility and on‐demand removal properties. A significantly improved hemostatic efficacy is demonstrated in the rat liver, spleen, and femoral artery injury models compared to that of the CM, commercial fibrin glue, and Yunnan Baiyao (YB). The GAP can also halt the severe bleeding from pig visceral organs. Overall, the proposed GAP has many advantages including good biocompatibility, rapid and effective hemostasis, low cost, and ease of use, making it as a promising hemostat for lethal non‐compressible hemorrhage control.