Water-Triggered Self-Expanding Agarose/Chitosan-Gallate Hemostatic Sponge for Incompressible Wounds

Incompressible deep wound bleeding is difficult to control and remains a formidable challenge. Here, a water-triggered self-expanding hemostatic sponge (AG/GA-CS) was prepared using agarose (AG) and gallic acid-modified chitosan (GA-CS) via sequential physical mixing, freeze-drying, and a compression fixation process. The prepared AG/GA-CS sponge showed high mechanical performance and can expand rapidly after absorbing liquid, which can provide pressure on the wound to close it and ultimately form a physical hemostatic barrier to promote hemostasis. In addition, it showed good antioxidant performance and effectively inhibited bacterial proliferation. Moreover, the AG/GA-CS sponge can rapidly absorb blood and promote efficient aggregation and activation of negatively charged erythrocytes and platelets on its surface, further significantly improving the blood clotting efficiency. On this basis, in vivo, the hemostatic effect was investigated using three hemorrhage animal models, namely, the mouse liver puncture model, mouse femoral artery hemorrhage model, and rat liver defect model. Results suggested that the prepared AG/GA-CS sponge showed superior hemostatic effects compared with the commercial gelatin sponge. In particular, the total amount of bleeding was sharply reduced by about five times within 5 s in the rat liver defect model. Therefore, the prepared AG/GA-CS sponges showed potential applications in the hemostasis of incompressible wounds.