Fabrication of porous starch microspheres by electrostatic spray and supercritical CO and its hemostatic performance.

Effective control of bleeding is critical to saving lives whether on the battle field or in civilian life. Microporous starch (MS) is a promising hemostat for its extensive sources, huge surface area and good biocompatibility. However, the hemostatic performance of MS is limited because of its complex preparation process and lack of effective component to activate coagulation factors. Herein, porous starch microspheres modified by calcium (Ca-PSM) with dense shell and honeycomb micro-porous core were prepared by electrostatic spray and supercritical CO for the first time. The topological morphology of Ca-PSM changed with the increase of Tween-80 content within 0.5%. Ca-PSM possessed excellent water absorbability due to high specific surface area, and what's more, it showed good hemostatic performance because of the synergistic effects of physical adsorption and chemical activation mechanisms. The results of thrombelastograph (TEG) showed that the initial clotting time (R) and coagulation time (R + K) of Ca-PSM-1 were shortened by 47.1%, 53.3% than that of control group. The maximum blood clot strength (MA) of Ca-PSM-1 was also significantly raised. Furthermore, it was noteworthy that Ca-PSM could activate clotting cascade and induce erythrocyte adsorption. In summary, Ca-PSM as a hemostat will be a promising and alternative candidate for clinical application.