Lethal hemorrhage could endanger lives. Although many hemostatic agents are commercially available with good clinical effect, it is necessary to develop novel hemostatic materials with high efficacy, biological safety, low cost, easily preparation and excellent biodegradability and biocompatibility. Here, novel biodegradable and uniform microspheres with regular spherical architecture and porous microstructure were prepared by thermosensitive carboxymethyl chitin (CMCH) with low substitution degree and low deacetylation through physical-crosslinking at high temperature without using any toxic crosslinkers. The obtained CMCH microspheres (CMCH-MS) were non-cytotoxic, low hemolytic potential and biodegradable in the presence of lysozyme. In vitro blood clotting evaluation indicated that the porous microsphere network structures and the hydrophilicity of the CMCH could promote hemostasis due to the quick blood absorption and local concentration of the coagulation factors for the CMCH-MS. The CMCH-MS showed much better hemorrhage control than negative control and traditional hemostatic chitosan, similar hemostatic performance as commercialized cross-linked starch microspheres in both rat tail and liver models. Thus, the new biodegradable porous CMCH-MS may hold great potential for hemorrhage control in medical treatment.

致命性出血可能危及生命。虽然目前市面上已有多种止血剂，临床效果良好，但仍需开发高效、生物安全、成本低、制备容易、生物降解性和生物相容性优良的新型止血材料。在这里，在不使用任何有毒交联剂的情况下，通过高温物理交联，通过低取代度和低脱乙酰化的热敏羧甲基甲壳素（CMCH）制备了具有规则球形结构和多孔微观结构的新型可生物降解且均匀的微球。获得的CMCH微球（CMCH-MS）无细胞毒性，溶血能力低，在溶菌酶存在下可生物降解。体外凝血评估表明，由于 CMCH-MS 的血液吸收快和凝血因子的局部浓度，CMCH 的多孔微球网络结构和亲水性可以促进止血。CMCH-MS 显示出比阴性对照和传统止血壳聚糖更好的出血控制，在大鼠尾和肝脏模型中止血性能与商业化交联淀粉微球相似。因此，新型可生物降解的多孔 CMCH-MS 在医疗出血控制方面具有巨大潜力。