Green preparation of hierarchically structured hemostatic epoxy-amine sponge

Abstract

Materials with highly absorptive property have been used to control bleeding by creating a physical barrier at the wound. Additionally, studies have suggested that macroporosity, cationic chemical groups, and microparticle morphology are advantageous attributes for hemostatic materials. Yet, no study to date has capitalized on these properties synergistically and integrates them into the development of multifunctional materials for enhanced performance in hemorrhage hemostasis. Here we present the preparation of such a new hemostatic sponge material using a facile and green method. The process simply involves epoxy-amine click reaction in water coupled with the phenomenon of temperature induced phase separation of polymer solution. It enables the convergence of multiple key features with hemostasis significance into the material. Specifically, phase separation results in the epoxy-amine (EA) sponge being hierarchically structured, with macroporosity for high water uptake while its microparticle structural units amenable for encapsulation of hydrophobic guests. Additionally, the EA sponge is inherently rich in amine groups, and thus can potentially exhibit a positive charge-based procoagulant effect. The material is pliable, and demonstrates excellent hemocompatibility and cytocompatibility. It also shows improved hemostatic performance over commercial products of gauze and gelatin sponge, supported by findings of in vitro whole blood clotting study, as well as in vivo mouse-tail amputation and rat liver injury models. This new versatile material has shown strong promises to warrant further development of such a multifaceted intervention to significantly enhance hemostatic management of bleeding.