Blend films of silk fibroin and water-insoluble polyurethane prepared from an ionic liquid

In order to blend the water-insoluble and biocompatible polyurethane (PU) with silk fibroin (SF) to prepare water-insoluble films as a biomaterial, the ionic liquid, 1-butyl-3-methylimidazolium chloride (BMIMCI), was used to prepare a SF/BMIMCI solution, which was directly blended with PU solution in N, N-dimethylformamide (DMF). Infrared spectroscopy indicated that the solution blending led to chemical bonding between the two polymers and a beta-sheet structure was the main conformation of SF in the films. The hydrophilicity of the films increased with the content of SF, based on contact angle measurements. The composite showed good blood compatibility in coagulation time tests and has potential biomaterial applications. (C) 2011 Published by Elsevier B.V.