Facile fabrication of the porous three-dimensional regenerated silk fibroin scaffolds

In the present work, we report a new facile method to fabricate porous three-dimensional regenerated silk fibroin (RSF) scaffolds through n-butanol- and freezing-induced conformation transition and phase separation. The effects of RSF concentration, freezing temperature and n-butanol addition on the microstructure, the secondary structures of silk fibroin and apparent mechanical properties of the RSF scaffolds were investigated by SEM, 13C CP-MAS NMR spectra and mechanical testing, respectively. By adjusting the RSF concentration and n-butanol addition, the pore size of the scaffold could be controlled in the range from of 10μm to 350μm with 84%–98% of porosity. The tensile strength of the wet scaffold reached the maximum of 755.2±33.6kPa when the concentration of RSF solution was increased to 15% w/w. Moreover, post-treatment with ethanol further induced conformation transition of RSF from random coil or helix to β-sheet. The porous scaffolds prepared by this facile and energy-saving method with good biocompatibility will have great potential for application in tissue engineering. [Display omitted] •A new facile and energy-saving method to fabricate porous silk fibroin scaffolds;•Freeze-drying step (a typical high energy consuming process) is unnecessary;•Morphology and mechanical properties of scaffolds were easily controlled;•Ethanol post-treatment can be used to tune the degradation behavior