Biodegradation of Multilayer Silk Fibroin and Hydroxyapatite Composite Material
Silk fibroin (SF) films containing 5wt% of CaCl2 were prepared by a cast-film method from the degummed SF and then immersed into the simulated body fluid (SBF) to deposit hydroxyapatite (HAp) crystals. The multilayer film of HAp and SF (5-layers), and pure SF film (4-layers) were prepared by a thermo-compression method at 130 °C and 3MPa for 4min. The ratio of β-sheet structure against other structures in both samples showed almost same value of 55.8% and 55.1%. The swelling ratio and in vitro biodegradation were examined by incubating in phosphate-buffered saline (PBS) with and without protease XIV for 1 to 14 days. The changes of sample weight and its tensile strength were investigated. The multilayer film showed slower biodegradation and higher mechanical strength compared with pure SF film.
Takashi Nakamura, Kimihiro Yamashita and Masashi Neo
R. Kino et al., "Biodegradation of Multilayer Silk Fibroin and Hydroxyapatite Composite Material ", Key Engineering Materials, Vols. 309-311, pp. 1169-1172, 2006