Expandable Nanocomposite Shape-Memory Hemostat for the Treatment of Noncompressible Hemorrhage.

Noncompressible hemorrhage is a leading cause of death in both combat and lay settings, primarily due to the challenges in accessing and treating injuries deep within abdominal tissues where traditional compression-based methods are ineffective. Existing hemostatic materials fail to address the needs of large wound cavities, necessitating the development of advanced materials with rapid expansion and superior hemostatic properties. Here we report an expandable hemostat engineered from a nanocomposite-coated shape memory foam. This material exhibits rapid expansion, achieving a ~5X increase in volume within 3 min in vitro, and demonstrates notable shape recovery in vivo. The material's hemostatic efficacy is evident through a ~70% reduction in clotting time compared to untreated controls, primarily due to the ability to adhere platelets and red blood cells. Moreover, the composite material displays excellent hemocompatibility and cytocompatibility, with low hemolysis rates and high cellular viability. In vivo assessments further confirm its effectiveness, showing an accelerated clotting time (~80% reduction) and decreased blood loss (~50% decrease), alongside minimal inflammation and necrosis in histological analyses. Additionally, the composite demonstrates good biocompatibility following subcutaneous implantation, illustrating its efficacy in vivo. Overall, the synergistic effect of rapid expansion by shape memory foam, along with the excellent procoagulant ability of the nanocomposite makes this biocompatible, expandable hemostat a promising treatment for noncompressible hemorrhage.