Fabricating poly(vinyl alcohol)/gelatin composite sponges with high absorbency and water-triggered expansion for noncompressible hemorrhage and wound healing.

It is challenging for traditional hemostatic sponges to control massive and noncompressible hemorrhages in the military field and accidental trauma. In this work, a series of highly fluid-absorbent composite sponges with rapid expansion ability based on norbornene anhydride-modified poly(vinyl alcohol) and gelatin (PVA@Gel-Sps) were developed by a foaming technique, chemical and physical crosslinking reactions and lyophilization. The prepared PVA@Gel-Sp exhibited a 3500% maximum water absorption ratio with a fast water absorption speed, which was suitable for blood component concentration. Owing to its interconnected macroporous structure, robust mechanical strength and high resilience, the compressed sponge could rapidly re-expand to more than 10 times its volume in response to water and blood. Moreover, due to the synergistic effect of the PVA-based sponge and gelatin, PVA@Gel-Sp could obviously shorten the hemostasis time and reduce blood loss in SD rat liver defect noncompressible hemorrhage models, and exhibited better wound healing effects in a full-thickness skin defect model than commercial sponges. These results suggest that PVA@Gel-Sp is a potential candidate for controlling noncompressible hemorrhage and promoting wound healing.