Active Blood Cell Capture and Synergistic Coassembly: Self-Gelling Gelatin-Polysaccharide Powders for Rapid...

While effective for irregular wounds, traditional hemostatic powders often lack posthydration cross-linking, yielding fragile barriers susceptible to washout under high-pressure hemorrhage. To address this, a novel self-gelling composite powder (GOQL) was developed by incorporating dopamine-grafted gelatin (GelDA), oxidized sodium alginate (OSA), and lauric acid-grafted quaternized chitosan (QCS-LA). Upon contact with bleeding sites, the porous powder swiftly absorbs interfacial fluids, triggering rapid in situ self-gelation through Schiff-base reactions and physical interactions, followed by progressive network maturation. During this process, blood cells are rapidly captured and retained through multiple interfacial interactions mediated by the functionalized macromolecules. The coupling of polymer-network formation with blood cell capture and retention contributes to the synergistic coassembly of a robust "blood cell-polymer" composite barrier. In vitro evaluations revealed firm tissue adhesion and potent procoagulant activity. In vivo, GOQL demonstrated excellent hemostatic efficacy in rat tail amputation and liver cruciate incision. Notably, in high-pressure femoral artery puncture and transection, the powder formed a stable hydrogel barrier within 30 s, effectively sealing the ruptured vessels. Furthermore, GOQL displayed favorable biocompatibility and biodegradability. Overall, by integrating ease of application, rapid in situ gelation, active blood cell capture and retention, and reliable tissue sealing, GOQL composite powder offers a highly promising strategy for managing severe traumatic hemorrhage.