Structural and Functional Changes of Silk Fibroin Scaffold Due to Hydrolytic Degradation

In this study, hydrolytic degradation of silk fibroin (SF) in Phosphate buffer saline (PBS) after 12 weeks incubation was investigated. Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and X-ray diffraction (XRD) patterns have confirmed the transition from crystalline β-sheet to random coil in treated SF. A decrease in adhesion force and surface Young's modulus were observed using atomic force microscopy (AFM). Structural changes were further confirmed using scanning electron microscopy (SEM). Biocompatibility and alkaline phosphatase production of osteoblast cells were decreased significantly in treated SF scaffold. Moreover, a significant decrease in mRNA level of collagen type I and osteopontin compared with fresh SF scaffold was observed. Finally, structural and biological characteristics of SF scaffold could alter in PBS. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014, 131, 39980. Copyright © 2013 Wiley Periodicals, Inc.