Chitosan-Based Powder with Ultrafast Powder-Gel Transition for Accelerated Hemostasis and Enhanced Tissue Regeneration

Post-traumatic uncontrolled bleeding is a major cause of trauma-related mortality, especially in cases involving irregular and noncompressible wounds. Existing commercial hemostatic powders face limitations such as unstable clot formation, poor tissue adhesion, and suboptimal biocompatibility, which restrict their clinical applicability. To address this, we developed a chitosan (CS)/poly(acrylic acid) (polyacrylic acid (PAA))-based composite hemostatic powder (CP powder) for effective management of noncompressible bleeding. The CP powder was obtained by dehydrating and grinding the CS/PAA hydrogel. They could rapidly absorb a large volume of fluid at the bleeding site and undergo an in situ transformation into a hydrogel state only within 10 s. In vitro experiments verified its excellent antibacterial efficacy, hemocompatibility, immunoregulation, and coagulation performance. In vivo experiments confirmed its efficacy in achieving rapid hemostasis in noncompressible wounds and modulating the immune microenvironment to promote tissue regeneration. The CP powder combines the quick hemostasis and enhanced tissue regeneration, offering a promising strategy for managing severe bleeding in clinical and emergency settings.