Liquid-Activated Self-Expanding Chitosan Shape Memory Cryogel for Rapid Hemostasis in Penetrating Wounds with Coagulation Disorders.

Due to the complexity of anatomical structure, noncompressible hemorrhage in coagulation disorders often misses the ″golden window" of emergency treatment and becomes the key problem in trauma management. In this work, CS/ODX-G shape-memory cryogel with three-dimensional interoperable porous structure based on chitosan/oxidized dextran system was constructed by a strategy of synergistic cross-linking of dynamic Schiff base bonding and covalent bonding. The cryogel can be implanted minimally invasively with precompression technology. It swells rapidly in situ with blood triggering and utilizes elastic recoil properties to precisely conform to irregular wounds and create a dynamic mechanical compression effect. Additionally, synergistic effects of the capillary effect of multistage channels and surface amine protonation promote fibrin deposition, ultimately forming a multimode coordinated hemostatic mechanism of "morphology adaptation-mechanical compression-coagulation regulation". Meanwhile, cryogels exhibit broad-spectrum antimicrobial resistance and outstanding biocompatibility. In rat tail amputation, rat liver perforation, and normal/coagulopathic rabbit liver hemorrhage models, CS/ODX-G cryogel demonstrated excellent hemostatic efficacy and significant clinical advantages. Through multilevel structural design and coagulation pathway regulation, this work innovatively exploits cryogel that can adapt to the morphology of deep cavities and expedite the coagulation cascade, providing a hemostatic solution with rapid response and intelligent regulation for battlefield injuries (especially for patients with deep wounds and coagulopathies).