Bioinspired Fibrin-Trapping Microspheres Enable Supra-Physiological Clot Formation Under High-Pressure Hemostasis

Rapid capture of fibrin and platelets is critical in high-pressure hemorrhage. However, many conventional hemostatic agents fail to sequester fibrin and assemble a stable clot, which limits their effectiveness in emergency care. In this study, hydroxyapatite (HAp)-doped gelatin microspheres (GHMPs-10) are developed to enhance hemostasis in high-pressure hemorrhage by accelerating the coagulation process. Initially, the surface-exposed HAp domains of GHMPs-10 facilitates the rapid recruitment of fibrinogen and its subsequent assembly into a robust network, enhancing the entrapment of platelets and erythrocytes to stabilize the thrombus. In addition, hydrophilic groups in the gelatin matrix enable rapid fluid uptake and microsphere expansion (≈718%). This concentrates local coagulation factors and platelets and accelerates fibrin network formation, while the expanded microspheres mechanically occlude the injury site. Functionally, GHMPs-10 withstood ≈191.5 mmHg in burst-pressure testing and, across multiple animal models, achieved shorter hemostasis times with lower blood loss than commercial powders. By rapidly initiating coagulation and concentrating blood components to form a mechanically robust hydrogel clot, these fibrinogen-capturing microspheres emerge as a highly promising candidate for rapid hemostasis, with potential for clinical translation.