Metal ion-protein-based liquid hemostatic foam for prehospital emergency treatment of incompressible hemorrhage

Mortality resulting from incompressible hemorrhage is the primary cause of pre-hospital deaths, highlighting the urgent need for the development of innovative hemostatic materials capable of effectively managing this type of bleeding. Inspired by the long-lasting foams constituted by transition metal ion-protein complexes, we have developed an injectable and stable liquid hemostatic foam composed of gelatin/silk fibroin and hemostatic metal ions Ca²⁺/Fe²⁺. This foam can be rapidly obtained using a simple double-syringe Tessari method and exhibits superior mechanical strength, longevity, and rheological properties compared to traditional pure gelatin foam. We characterized the size changes and blood interactions of the foam under an optical microscope. Benefiting from the synergistic effects of multiple pro-coagulation components, the foam demonstrated superior hemostatic performance in rat liver injury, femoral artery injury, and porcine superficial epigastric artery injury models compared to commercial gauze and gelatin sponge. After hemostasis, the foam can be retained on the wound, where it rapidly and harmlessly degrades, mitigating inflammatory responses and reducing unnecessary adhesions Alternatively, it can be gently, rapidly, and intact removed from the wound through a simple process, without damaging the formed clot and causing secondary bleeding, thus facilitating further treatment of casualties. These functions highlight its great potential for prehospital emergency treatment of incompressible hemorrhage. STATEMENT OF SIGNIFICANCE: We have developed a liquid hemostatic foam for rapid hemostasis of incompressible hemorrhage. The foam shows consistent stability, mechanical strength, and duration, meeting the requirements for managing incompressible hemorrhage. The foam can be easily removed from the wound without disrupting the clot or causing secondary bleeding, which is beneficial for pre-hospital rescue. We believe that such liquid hemostatic foam materials, benefiting from injectability and improved mechanical strength, are actually more advantageous for pre-hospital treatment of incompressible hemorrhage. We also hope that there will be more research in this field in the future to further optimize and develop liquid foam hemostatic materials.