Green and Efficient Preparation of Chitosan-Based Sponge with In Situ Synthesized ZnO for Deep Trauma Bleeding and Wound Healing

Deep trauma often leads to acute bleeding and infections, which are major causes of death. It is worth exploring the preparation of hemostatic materials and improving their hemostatic and antibacterial properties applied to deep trauma by green and efficient methods. In this study, porous chitosan/zinc oxide/alkylated chitosan (CS/ZnO/ACS) sponges were prepared by a freezing phase separation method. ACS induced the formation of stable foam, increasing the pore formation during the freezing phase separation process. The porous structure enabled the sponge to rapidly absorb blood and expand to close the wound. The in situ synthesis of ZnO within the sponge enhances its antibacterial properties. In the antibacterial test against S. aureus and E. coli, the CS/ZnO/ACS sponges can effectively inhibit bacterial growth. Besides, compared with CS sponges, the introduction of ACS increases the adhesion of the CS/ZnO/ACS sponges to blood cells and promotes coagulation. In addition, the CS/ZnO/ACS sponges were prepared by physical phase separation, which endows it with increased solubility under acidic conditions and can be quickly removed after hemostasis. Therefore, the CS/ZnO/ACS expandable sponges offer promising clinical applications for the treatment of deep trauma.