Biodegradable carboxymethyl chitin-based hemostatic sponges with high strength and shape memory for non-compressible hemorrhage.

Uncontrolled hemorrhage of deep, narrow and non-compressible perforating wounds is responsible for many trauma deaths. In this work, a novel biodegradable hemostatic sponge based on thermosensitive carboxymethyl chitin was prepared via simple cryo-regeneration process without using any crosslinkers. The collagen and polydopamine were added to further enhance mechanical and hemostatic properties of the sponge. All the carboxymethyl chitin based sponges showed high strength with excellent water/blood-triggered shape memory property, and the highest compressive fracture wet-strength could reach about 291.2 kPa, which was almost higher than those of many reported biodegradable hemostatic sponges pre-swelled in water. More importantly, the carboxymethyl chitin-collagen-polydopamine sponges displayed much better blood-clotting capacity and superior hemostasis performance than gauze and clinically used collagen sponge iRegene@ in vitro and in the rat liver perforating wound model. This study revealed a facile strategy to construct the effective carboxymethyl chitin based hemostatic sponges for the deep and non-compressible perforating wound.