Hemostatic Sponge Based on Modified Alginate and Water-Soluble Chitosan for Rapid Hemorrhage Control

Hemorrhage remains a leading cause of preventable mortality in trauma and surgical settings, necessitating hemostatic materials that act rapidly while maintaining mechanical integrity and safety. Here, we report a flexible hemostatic sponge composed of 2-(dimethylamino)ethyl methacrylate (DMAEMA)-modified water-soluble chitosan and dual-functionalized alginate derivatives (alendronate- and 3-(dimethylamino)-1-propylamine (DMPA)-modified alginate). The materials were synthesized entirely in aqueous media and processed via controlled freezing followed by freeze-drying, yielding partially ionically cross-linked porous scaffolds (∼85% porosity) with rapid swelling (up to ∼4500% within 10 min) and efficient blood absorption. Structural characterization confirmed successful functionalization, while the scaffolds exhibited tensile strengths of 260-290 kPa and maintained structural integrity under physiological conditions for up to 2 weeks. The sponges demonstrated low hemolysis (<8%) and high fibroblast viability (>95%), indicating good hemocompatibility and cytocompatibility. In a mouse liver hemorrhage model, the material significantly reduced blood loss (84.3%) and exhibited hemostatic performance comparable to the commercial control KALTOSTAT. This dual-modification strategy integrates a Ca²⁺-mediated coagulation support, rapid fluid absorption, and cationic blood-material interactions, enabling effective bleeding control while maintaining structural durability. These findings highlight the potential of the WS-C/MA sponge for emergency and surgical hemostasis.