Ultrafast self-gelling, sprayable, and adhesive carboxymethyl chitosan/ poly-γ-glutamic acid/oxidized dextran powder for effective gastric perforation hemostasis and wound healing

The rapid and effective hemostasis of gastrointestinal bleeding sites remains an urgent clinical challenge. In this study, an ultrafast self-gelling, sprayable, and adhesive carboxymethyl chitosan/poly-gamma-glutamic acid/oxidized dextran (CPO) powder was designed for gastric perforation hemostasis and healing. When the CPO powder was sprayed to the gastric perforation site, the CPO powder absorbed water from the blood and concentrate blood cells and clotting factors to achieve the purpose of rapid hemostasis. During the hemostasis, the CPO powder formed a hydrogel in situ through the formation of amide bonds and Schiff base bonds within 15 s, forming a physical barrier to cover the wound surface. Concurrently, the aldehyde group (-CHO) of oxidized dextran formed additional Schiff base bonds with the amino group (-NH2) of the tissue, enabling the CPO powder with wound surface adhesion. Moreover, the CPO powder was shown to have excellent in vitro and in vivo antibacterial properties and it was able to promote the healing of infected wounds in a mouse model. In summary, CPO powder provides a promising idea for the rational design of gastrointestinal hemostatic agents.