Quaternary Ammonium Groups Modified Starch Microspheres for Instant Hemorrhage Control.

Instant rapid hemostasis is crucial not only for decreasing mortality in these conditions, but also for optimal recovery. The hemostatic agents on the market suffer from inefficiency hemostasis, nondegradability, high cost and potential safety issues. It is necessary to develop a hemostatic agent with rapid hemostatic performance, potent biodegradation and improved biocompatibility. The aim of this work was to develop a novel type of cationic modified starch microspheres (CS) and investigate its hemostatic performance. CS was firstly developed via enzymatic hydrolysis and then assembled with quaternary ammonium groups by etherification reaction with microsporous starch. The result showed that CH3 -N+ groups were successfully grafted on the backbone of CS. The zeta potential of CS was increased by 19 mv and the viscosity was improved with a tenfold. Rapid water absorption ratio (304.2%, only 81.8% of pure Starch) and high swelling capacity of CS (1008%, nearly quadruple higher than pure Starch), together with its porous structure, enhanced the physical hemostatic efficacy. In addition, in vitro coagulation studies showed that CS induced the adhesion of red blood cell and platelet, and thus activated the blood chemical coagulation system due to the positive charge. In vivo studies in rabbit liver injuries model further confirmed the dramatic improvement in the hemostatic capacity of CS because the synergistic effects of the chemical activation mechanism and physical absorption mechanism. Furthermore, the degradation of CS was greatly improved by the modification. This study suggested the quaternary ammonium groups modified starch microspheres could serve as an effective and promising hemostatic agent for instant rapid hemostasis.