Electrospinning of reconstituted silk fiber from aqueous silk fibroin solution

Silk nanofibers were successfully prepared by electrospinning an aqueous solution of regenerated silk fibroin (RSF, from Bombyx mori) with higher molecular weight. Many factors, such as concentration, electrical conductivity of the fibroin solution and applied electric field were found to influence the morphology of these nanofibers. The conformation of RSF nanofibers was transformed from random coil/helical to beta-sheet after the post treatment with pure ethanol. Under optimal conditions, the as-spun non-woven mats achieved good mechanical properties. The apparent stress and strain at break were 11.1 +/- 0.7 MPa and 10.2 +/- 1.6%. respectively, which is important for the application of such a unique fibrous protein. (C) 2009 Elsevier B.V. All rights reserved.