Development of gelatin/zein fibrous membranes for hemostatic application

Microporous structures are usually designed for hemostatic agents to dehydrate blood and thus accelerate the natural clotting process. We have developed gelatin-based fibrous membranes by co-electrospinning with a hydrophobic protein, zein, for hemostatic dressings. The hybrid gelatin/zein fibers showed structural integrity upon introduction into an aqueous medium without the subsequent crosslinking of the protein components. Fibrous membranes with different gelatin/zein ratios were characterized by blood absorption, whole blood clotting, and coagulation activity in vitro and hemostatic efficiency in vivo. The results indicated that both blood and simulated body fluid uptake were increased as zein content of hybrid fibers decreased, in correspondence to the increase of hydrophilicity of the membranes. Coagulation activity tests showed that both components did not activate coagulation at all, indicating that the gelatin/zein fibrous membrane provided a physical matrix for clotting to be initiated. Adequate hemostatic efficacy was observed after applying gelatin/zein fibrous membranes to bleeding sites on the auricular vein, middle auricular artery, and liver of rabbits. In different hemorrhage models, fibrous membranes with a gelatin/zein ratio of 3/1 showed the least bleeding time and blood loss among the other membranes as well as control (gelatin sponge). Moreover, the total blood loss in the liver injury using the membrane (50.7 mg ± 3.8 mg) was significantly less than that of the control (182.5 mg ± 40.3 mg). Overall results demonstrated that gelatin/zein fibrous membranes with fibrous structure and moderate fluid absorption ability showed rapid hemostasis and limited blood loss, which could be of great benefit for hemostatic applications.