A triple-network carboxymethyl chitosan-based hydrogel for hemostasis of incompressible bleeding on wet wound surfaces

Hydrogel is a kind of hemostatic agent with good application prospect. However, the water molecules on the wound made the hydrogel less adhesive to wet wound tissue. Herein, the carboxymethyl chitosan (CMCS)/oxidized dextran (OD)/γ-polyglutamic acid (γ-PGA) hydrogel was prepared using a double-barreled syringe for hemostasis of diffuse and incompressible wound bleeding. The hydrogel formation was based on the intramolecular lactam bonds, intermolecular amide bonds, and Schiff base bonds. In the hydrogel, the super hydrophilic γ-PGA could drain the surface moisture of the wound and create a local dry environment for enhanced surface adhesion. In vivo study showed that the CMCS/ODex/γ-PGA hydrogel possesses a good biosafety and biodegradability. Interestingly, the CMCS/ODex/γ-PGA hydrogel exhibited excellent hemostatic abilities in dynamic humid environment and resisted a high blood pressure of 238 mmHg, which exceeds the threshold systolic blood pressure of healthy adults (i.e., 120 mmHg). Together with the antibacterial and reactive nitrogen species scavenging activities, this study is expected to provide a new method to design the wet-surface adhesives for the efficient hemostatic application.