3D porous chitin sponge with high absorbency, rapid shape recovery, and excellent antibacterial activities for noncompressible wound

Effective hemostasis as well as antibacterial infection are the urgent challenge for deep, narrow, irregular, and non-compressible wounds. In this work, a robust 3D porous sponges with quaternary chitin/partially deacetylated chitin nanofibers as its skeleton (QCNS) was reported. Thanks to the interconnected microporous, hydrophilicity and robust mechanical properties, QCNS possessed high-water absorption ratio (7534 ± 151%–13044 ± 275%) and even displayed superfast water/blood-trigged shape recovery performance (less than 1 s), allowing it to be delivered into the wound cavity in the shape of small particle and fleetly expand its volume on contacting the blood to fill the wound. Furthermore, due to its high-water uptake and positive-charge feature, QCNS could attract and stimulate blood cells/platelets, thus further promoting blood coagulation. When applied in the cylindrical wound on rat liver as noncompressible wound models, QCNS displayed superior hemostatic performance than traditional hemostatic materials such as medical gauze, gelatin sponge and Celox™. More importantly, QCNS displayed excellent antibacterial activity, cytocompatibility, and hemocompatibility. These outstanding superiorities in water absorption, water-trigged shape recovery, mechanical properties, blood-clotting ability, cytocompatibility, hemocompatibility, as well as antibacterial activity endow QCNS high potential application in hemostasis for noncompressible trauma and ballistic injuries.