Porous chitosan microspheres containing zinc ion for enhanced thrombosis and hemostasis

摘要

AbstractQuick hemostats for non-lethal massive traumatic bleeding in battlefield and civilian accidents are important for reducing mortality and medical costs. Chitosan (CS) has been widely used as a clinic hemostat. To enhance its hemostatic efficiency, Zn2+in the form of zinc alginate (ZnAlg) was introduced to CS to make porous CS@ZnAlg microspheres with ZnAlg component on the surface. Such microspheres were prepared by successive steps of micro-emulsion, polyelectrolyte adhesion, and thermally induced phase separation. Their structure and hemostatic performance were analyzed by SEM, FT-IR, XPS and a series ofin vitrohemostatic experiments including thromboelastography analysis. The composite microspheres had an outer and internal interconnected porous structure. Their size, surface area, and water absorption ratio wereca.70μm, 48m2/g, and 1850%, respectively. Compared to the neat chitosan microspheres, the CS@ZnAlg microspheres showed shorter onset of clot formation, much fasterin vitroandin vivowhole blood clotting, bigger clot, less blood loss, and shorter hemostatic time in the rat liver laceration and tail amputation models. The synergetic hemostatic effects from (1) the electrostatic attraction between chitosan component and red blood cells, (2) the activation of coagulation factor XII by Zn2+of zinc alginate component, and (3) physical blocking by microsphere matrix, contributed to the enhanced hemostatic performance of CS@ZnAlg microspheres.Highlights•Chitosan@Zn-alginate microspheres with enhanced hemostatic potential were fabricated.•Zn2+released from chitosan@Zn-alginate microspheres accelerated the formation of clot.•The onset of fibrin formation was measured by TEG.