Development of PVA /Chitosan Aerogels With Fishbone‐Like Anisotropic Structures for Rapid Hemostasis

ABSTRACT Efficient hemostasis remains a major challenge in treating noncompressible bleeding wounds, thereby necessitating the development of haemostatic materials with both excellent clotting performance and antimicrobial activity. To address this need, we fabricated chitosan/poly(vinyl alcohol) (CS/PVA) hybrid aerogels with anisotropic structures via sol–gel and freeze‐drying methods. The aerogel was further crosslinked through interactions between Fe 3+ , protocatechualdehyde (PA), and chitosan (CS), which imparted antimicrobial functionality. By modulating the PVA content, the aerogels exhibited a fishbone‐like axial structure and a uniform radial honeycomb structure (77.8 μm pore size), with an axial elastic modulus that was nearly an order of magnitude greater than the radial elastic modulus. At 66% solid content and 80% compressive strain, the aerogel achieved a compressive stress > 2.2 MPa and toughness of 450 kJ/m 3 , thereby significantly surpassing those of conventional aerogels. In rat liver hemorrhage models, the CS/PVA aerogel reduced the bleeding volume by approximately 73% and the hemostasis time by approximately 50% compared with those of the blank controls and gelatine sponges. Additionally, it demonstrated strong antibacterial activity against Staphylococcus aureus and Escherichia coli , along with excellent biocompatibility (no cytotoxicity or haemolysis being observed). This multifunctional aerogel demonstrates promising potential for managing noncompressible wound hemorrhage.