Develop a More Biodegradable/Biocompatible Hemostatic Fabric for Treatment of Bleeding Wounds

Abstract

Hemostatic wound dressings help control traumatic external bleeding by enhancing or accelerating the natural clotting process through various physical reactions. Since the fatal traumatic hemorrhage remains one of the most challenging problems for both military and civilian medicine, efficient hemostatic wound dressings have been in high demand. Currently, several hemostatic dressings have been commercially available for acute hemorrhage, however, they still have some limitations in terms of cytotoxicity, biodegradability, sterilization, and cost performance. Thus, the development of effective biocompatible hemostatic dressings that overcome these limitations has been needed. The goal of this study is to investigate the potential application of Bombyx mori silk fibroin fibers as hemostatic wound dressings. First, the silk fibers were treated with two kinds of neutral salt [calcium nitrate tetra-hydrate (Ca(NO3)2 4H2O) and calcium chloride (CaCl2) ] / alcohol [methanol and ethanol] systems in order to decrystallize theirβ-sheet crystalline structure and improve the water absorbability and biodegradability. The decrystallization was carried out by controlling the solvent concentration and environment temperature. FTIR and X-ray demonstrated that most effective decrystallization of silk fibers were performed with the treatment in 50% (w/w) Ca(NO3)2 4H2O/methanol at 65℃, accompanying obvious decrease in the crystal size. Next, the blood clotting ability of the treated silk fibers was investigated by blood coagulation test. Even though any evident blood clot formation on the silk fibers was not confirmed during the test, the blood was separated into two phases and erythrocyte sedimentation was observed at different rate for each specimen. The silk fibers treated with most severe condition caused slower erythrocyte sedimentation compared with the non-treated silk fibers, suggesting less blood coagulation ability. Previously it has been reported that surface of silk fibroin fibers is hydrophobic and blood proteins interact with the silk fibroin through strong hydrophobic interaction. The obtained results suggest us that the decrease in hydrophobicity of the silk fibers surface due to decrystallization resulted in less interaction with blood proteins. Based on this result, we modified the silk fibers with sodium dodecyl sulfate (SDS) to give hydrophobic portion on the silk fiber surface. The difference in blood coagulation behavior between SDS-modified fibers and non-modified fibers was compared.