Polyurethane Sponges with Releasing Calcium Ions for Rapid Hemostasis

Traumatic hemorrhage is the main cause of death; therefore, the development of materials with excellent hemostatic function is of great significance. Thanks to the good biocompatibility, polyurethane sponge (PUS) has great application prospects in hemostasis. In this study, five types of PUSs with different calcium ion contents (PUSCas) were prepared by the chemical foaming method, labeled as PUSCa0 (0%), PUSCa15 (1.5%), PUSCa30 (3.0%), PUSCa45 (4.5%), and PUSCa60 (6.0%). The effects of calcium ion content on the pore structure, mechanical strength, and liquid absorption of PUSCas were explored. The results showed that the liquid absorption and mechanical strength of PUSCas increased with the increase of calcium ion content, while the pore size, pore wall thickness, and density of PUSCas showed an opposite trend. In addition, the result of biocompatibility in vitro indicated that the introduction of calcium ions did not increase the biological toxicity of PUSCas but significantly increased the in vitro coagulation rate. In a mouse model of femoral artery free hemorrhage, the hemostasis time (57 ± 3 s) and blood loss value (105 ± 6 mg) of PUSCa60 were better than those of PUSCa0 (145 ± 5 and 276 ± 10 mg). Furthermore, these results of plasma coagulation experiments confirmed that PUSCas participated in endogenous and exogenous coagulation pathways by releasing calcium ions, promoting the formation of fibrin oligomers, and ultimately enhancing hemostasis. This PUSCa exhibits broad clinical application prospects in hemostasis.