Preparation and properties of chitin/silk fibroin biocompatible composite fibers

In the present world chitin is used enormously in various fields, such as biopharmaceuticals, medical and clinical bioproducts, food packaging, etc. However, its development has been curbed by the impaired performance and cumbersome dissolution process when chitin materials are dissolved and regenerated by physical or chemical methods. To further obtain the regenerated chitin fiber material with improved performance, silk fibroin was introduced into the chitin matrix material, and chitin/silk fibroin biocompatible composite fibers were obtained by formic acid/calcium chloride/ethanol ternary system and top-down wet spinning technology. The produced composite fibers outperformed previously reported chitin-silk composites in terms of the tensile strength (160 MPa) and failure strain (25%). The fibers also performed good cell compatibility and strong cellular affinity for non-toxicity. The cell viabilities of the fibers were about 20% greater than those of silk fiber after three days of co-culture with NIH-3T3. Furthermore, no hemolysis occurs in the presence of chitin/silk fibers, demonstrating their superior hemocompatibility. The fibers had a hemolysis index as low as 1%, which is far lower than the acceptable level of 5%. The material offers prospective opportunities for biomaterial applications in anticoagulation, absorbable surgical sutures, etc.