Superwettable calcium ion exchanged carboxymethyl cellulose powder with self-gelation, tissue adhesion and bioabsorption for effective hemorrhage control

Water-soluble polymers can be used to develop self-gelling hemostatic powders, and powder wettability potentially plays the key role in determining their hemostatic efficacy. Herein, a superwettable calcium ion exchanged carboxymethyl cellulose (Ca-ex-CMC) powder is reported for effective hemorrhage control. Despite being water-soluble, Ca-ex-CMC powder can form a physically crosslinked hydrogel upon contact with water (self-gelation), and the rate of water permeating the hydrogel to achieve dissolution is extremely slow. With increased calcium content, Ca-ex-CMC powder shows not only improved procoagulant activity, but enhanced wettability which can facilitate the fusion of the powders with water, resulting in promoted water uptake and insitu formation of strong hydrogel barriers with enhanced tissue adhesion. Applying Ca-ex-CMC powder to noncompressible (liver and tail) and massive (artery) hemorrhage wounds in rat and rabbit models can stanch bleeding instantly, because of complete sealing of the bleeding sites by enhanced in-situ self-gelation. Moreover, owing to water-solubility, Ca-ex-CMC powder shows outstanding bioabsorbability and histocompatibility after implantation into rabbit liver and gluteus. These findings not only support Ca-ex-CMC powder as a promising hemostatic agent for extensive application but identify the critical role of wettability in promoting hemostasis for self-gelling powders.