Physical and Chemical Characteristics of Silk Fibroin/Fucoidan Composite Films
摘要
BACKGROUND: Silk fibroin blend films with α-helix cannot be used as biomaterials due to water-soluble and unstable; however, β-sheet structure is stable. OBJECTIVE: To prepare for a β-sheet conformation silk fibroin composite films mixing fucoidan and to observe the physical and chemical characteristics of silk fibroin /fucoidan composite films. DESIGN, TIME AND SETTING: The physical and chemical characteristics experiments of silk fibroin/fucoidan composite films were conducted in Chemistry Experiment Center of Institute of Chemistry Chinese Academy of Sciences and Chengde Petroleum College from November 2003 to August 2006. MATERIALS: Fucoidan was isolated from Laminaria Japonica, and Bombyx mori silk was commercially from China Import & Export Company. METHODS: The solution prepared with a different blend ratios aqueous solution of silk fibroin and fucoidan, was cast into a polystyrene plate and incubated at 25 ℃ and 65% relative humidity. Silk fibroin film was formed after dry the plate at the temperature. The composite films were well when the mixing rate of fucoidan was more than 20% (w). The silk fibroin solution and fucoidan solution were mixed according to the different mass ratios of silk fibroin and fucoidan, including 0:100, 5:95, 10:90, 20:80, and 100:0. The films were marked a, b, c, d and e, respectively. MAIN OUTCOME MEASURES: The physical and chemical characteristics of silk fibroin/fucoidan composite films were examined through Fourier transform infrared spectroscopy, X-ray diffractometry, and thermogravimetry. RESULTS: The conformation of silk fibroin in blend films was revealed to be β-sheet structure according to the results of Fourier transform infrared and X-ray diffractometry spectra. These results demonstrated that the conformation change of silk fibroin occurred from a random coil to a β-sheet structure due to the formation of intermolecular hydrogen bonds between fucoidan and silk fibroin in the blend films. Thermogravimetry showed t