A self-crosslinking powder based on carboxymethyl chitosan and guar gum with free radical scavenging for rapid hemostasis and promotion of wound healing

Uncontrolled non-compressible visceral hemorrhage and irregular wet wounds remain difficult to manage because many hemostatic powders lack robust wet adhesion and mechanical integrity under continuous blood flow, leading to displacement and rebleeding. Here, a multifunctional, natural-polysaccharide hemostatic powder (CSO) is engineered from carboxymethyl chitosan (CMCS), dopamine-grafted sodium alginate (SA-DA), and oxidized guar gum (OGM), and the mixture is activated by EDC/NHS to enable rapid, in situ self-crosslinking. Upon contact with wound, the CSO powder rapidly absorbs tissue exudate or blood, concentrates coagulation factors and blood cells, and undergoes in situ self-crosslinking to form a stable, adherent hydrogel that seals the wound for rapid hemostasis. The incorporated dopamine moiety endows the hydrogel with potent free radical scavenging ability, effectively mitigating oxidative stress and inflammation to accelerate wound healing. In addition, the CSO powder exhibits notable antimicrobial activity, helping to prevent post-hemostatic infection. In rat tail-amputation and liver-incision models, CSO achieves rapid hemostasis with markedly reduced blood loss, and further accelerates infected full-thickness skin repair by dampening inflammation and improving collagen remodeling. These features, together with favorable biocompatibility and practical applicability, position CSO as a promising powder-to-hydrogel platform for emergency and surgical hemostasis with improved healing outcomes.