Foam-Propelled Self-Gelling Hemostatic Powder Enabling Active Deep Delivery and Wet Tissue Adhesion for Complex Wound Bleeding

Most self-gelling hemostatic powders lack active delivery, limiting efficacy in deep, complex wounds. Herein, we develop a multifunctional self-gelling powder (QST) composed of quaternized chitosan (QCS), catechol-modified sodium alginate (SA-DA), protonated tranexamic acid (TXA-NH3+), and sodium bicarbonate (NaHCO3). The powder integrates rapid self-gelation (5 s), shape-adaptive swelling (4-fold volume expansion), self-propulsion, procoagulant capacity, and wet tissue adhesion (14.9 ± 0.6 kPa). Upon contact with blood, TXA-NH3+ reacts with NaHCO3 to generate CO2, driving powder self-expansion within 5 s, covering irregular bleeding surfaces. Concurrently, QCS and SA-DA undergo rapid gelation that traps red blood cells and activates the extrinsic coagulation pathway, forming a robust clot reinforced by the polymer network. Furthermore, owing to its good wet tissue adhesion, the hydrogel firmly anchors to the wound, resisting blood-flow erosion. Consequently, QST outperforms gelatin sponge and Celox in animal injury models. It also shows favorable antibacterial activity, cytocompatibility, degradability, and wound healing promotion.