Silk fibroin (SF) nanofiber scaffolds were made by electrospinning of fibroin fibers. Fibroin is a natural polymer with tremendous potential as a matrix for tissue engineering. Pure silk fibroin protein was extracted from Bombyx mori silk cocoon by degumming method using aqueous Na2CO3 solution followed by solubilizing in CaCl2-C2H5OH-H2O aqueous solution and frozen in liquid nitrogen, then lyophilized in freeze-dryer. The electrospinning of SF sponge was performed with formic acid, as a spinning solvent, at 7% (w/w) fibroin concentration. SF fibers with diameters down to the nanometer range, or nanofibers, are formed by subjecting a fluid jet to a high electric field. In this regard, voltage, flow rate and distance were used as variable parameters and effect of changes in these parameters were investigated. The morphology of SF nanofibers were characterized by scanning electron microscopy (SEM) at different magnification. After find the optimum parameters for electrospinning of SF nano fibers, Fibroblast L-929 cell line derived from normal subcutaneous areolar adipose tissue of mouse were cultured, expanded and seeded on selected electrospun SF nanofibers. Adhesion and proliferation of fibroblasts were investigated by MTT assay which showed no cytotoxicity and good choice for tissue engineering scaffold.
