A shape memory and antibacterial cryogel with rapid hemostasis for noncompressible hemorrhage and wound healing

Death from uncontrollable hemorrhage remains a worldwide concern, especially for deep noncompressible wounds caused by gunshot and sharp objects. However, traditional hemostatic methods such as gauze, tourniquets and direct pressure are not powerful enough for these extreme bleeding and promoting wound healing. In this study, a shape memory cryogel was prepared through mixing quaternized chitosan (QCS) and mesoporous bioactive glass (MBG) under -20 degrees C, in which MBG could activate intrinsic coagulation pathway and endow the cryogel with the function for promoting wound healing. The QCS/MBG cryogels possessed highly interconnected macroporous structure between 100 and 200 mu m and robust mechanical property, which could maintain stable even after undergoing 10 cycles compression test. The hemostatic results demonstrated that QSC/MBG cryogel exhibited desirable hemostasis effect for liver prick injury model (71.58 +/- 9.11 s) and liver noncompressible hemorrhage model (46.94 +/- 0.92 s) compared to commercial gelatin sponge. Meanwhile the cryogels also showed efficient antibacterial properties for both gram-positive and negative bacteria. Furthermore, MBG loaded cryogel significantly accelerated wound healing rate in infected full-thickness wound. In summary, the shape memory cryogel can quickly control bleeding as well as avoid bacterial infection and accelerate wound healing, which had great potential for clinical application as a novel multifunctional hemostatic.