Rapid and effective hemorrhage control is essential to reduce mortality following traumatic injuries. Herein we developed an organic solvent-free process to prepare carboxymethyl chitin microsphere (CMCHm) in an aqueous two-phase system through heating and freeze-drying. To further enhance the hemostatic performance of CMCHm, we loaded calcium ions and in-situ polymerized dopamine to get modified hemostatic microspheres CMCHm-Ca²⁺ and CMCHm-PDA, respectively. The size of these microspheres was mainly distributed between 50 μm and 150 μm, and the porous microstructure was observed by SEM. The data of in vitro degradation, cell cytotoxicity, and hemolysis test indicated good biocompatibility of these microspheres. Importantly, CMCHm-Ca²⁺ and CMCHm-PDA displayed better hemostatic performance compared with CMCHm and the positive controls Yunnan baiyao® and Quickclean®. Especially, the bleeding time was reduced to 59 s (CMCHm-Ca²⁺) and 45 s (CMCHm-PDA) in the femoral artery/vein cut model, respectively. All these demonstrate CMCHm-Ca²⁺ and CMCHm-PDA hold great potential for rapid hemostasis.

快速有效的出血控制对于降低外伤后的死亡率至关重要。在此，我们开发了一种无有机溶剂工艺，通过加热和冷冻干燥在水性两相体系中制备羧甲基甲壳素微球（CMCHm）。为了进一步增强CMCHm的止血性能，我们分别加载了钙离子和原位聚合的多巴胺，得到了改性止血微球CMCHm-Ca ²⁺和CMCHm-PDA。这些微球的尺寸主要分布在 50 μm 和 150 μm 之间，并通过 SEM 观察到多孔微观结构。体外降解、细胞毒性和溶血试验数据表明这些微球具有良好的生物相容性。重要的是，CMCHm-Ca ²⁺与 CMCHm 和阳性对照云南白药®和 Quickclean® 相比，CMCHm-PDA 显示出更好的止血性能。特别是，在股动脉/静脉切割模型中，出血时间分别减少到 59 s (CMCHm-Ca ²⁺ ) 和 45 s (CMCHm-PDA)。所有这些都表明 CMCHm-Ca ²⁺和 CMCHm-PDA 具有快速止血的巨大潜力。