BACKGROUND:Chitosan is a kind of biomaterial with good hemostatic, antibacterial and absorption properties. The guanidine modified chitosan holding better antibacterial and absorption abilities is a commonly used chemical separation material. However, its coagulation property is still unclear. OBJECTIVE:To evaluate the in vitro hemostatic property and cytotoxicity of the guanidine modified chitosan, and to explore its availability as a hemostatic material.METHODS:The guanidine modified chitosan was synthesized with the raw materials of chitosan and arginine, and the coupling agents of EDC and NHS. The coagulation ability was evaluated preliminarily through the whole blood coagulation time, and three in vitro coagulation indexes (activated partial thromboplastin time, prothrombin time and thrombin time). The guanidine modified chitosan extracts were co-cultured with the mouse fibroblasts, and then the cell growth was observed by MTT assay and fluorescence microscope. RESULTS AND CONCLUSION:The guanidine modified chitosan shortened the whole blood coagulation time, suggesting its hemostatic property. In vitro coagulation results indicated that the guanidine modified chitosan exerted the effect not through the traditional endogenous and extrinsic coagulation pathways. Guanidino group has not been proved to be hemostatic, so the chitosan may be the effective component. MTT assay showed that the cell proliferation rate was 87.8%and the toxicity level was grade 1. Fluorescent staining observed abundant live cells, and few dead cells, indicating that the guanidine modified chitosan exhibits low cytotoxicity.