AA/MA/AMA copolymer and chitosan as self-gelling powders for rapid hemostasis and robust tissue adhesion.

Bleeding control by traditional hemostatic materials poses a risk of continuing oozing bleeding, while existing self-gelling hemostatic powders still face challenges in simultaneously achieving robust wound sealing and effectively accelerating blood coagulation. Herein, we reported acrylic acid/methacrylic acid/2-aminoethyl methacrylate copolymer (PAMA) and chitosan (CS) as a new type of self-gelling composite powder (PAMA-CS) for acute bleeding wound sealing with reduced blood leakage. Upon rapid blood absorption, PAMA-CS powders could quickly form an adhesive hydrogel that strongly binds to bleeding tissues, exhibiting high burst pressure tolerance (up to 452.6 mmHg) for wound sealing to prevent bleeding. The incorporation of chitosan endowed significantly enhanced liquid uptake ability and accelerated blood coagulation (clot index of 77.92 % within 30 s) to the PAMA-CS powder. Based on the synergistic effect of tight adhesive sealing and accelerating intrinsic blood coagulation, PAMA-CS powders could achieve effective hemostasis within 20 s for acute bleeding liver and stomach on rats, outperforming commercial hemostatic chitosan powders. Combined with rapid hemostasis, tight & stable wound sealing, and favorable biodegradation, PAMA-CS powders may serve as a promising hemostatic candidate for emergency bleeding control and wound closure.