Fabrication and Characterization of Core-shell Structured Composite Nanofibrous Scaffolds by Coaxial Electrospinning

Biodegradable core-shell structured nanofibrous scaffolds with silk fibroin (SF) and poly(L-lactic acid-co-epsilon-caprolactone) (P(LLA-CL)) blends as shell and bovine serum albumin (BSA)-containing SF as core were fabricated by coaxial electrospinning. Morphology and microstructure of the nanofibers were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results demonstrated that core-shell structured nanofibers were obtained, furthermore, the nanofibers became greatly uniform and the average diameters were thinner in comparison with only core BSA solution after adding 10-20 w/v% SF in core BSA solution. The C-13 NMR clarified the SF conformation transformed from random coil to beta-sheet when treated with 75 w/v % ethanol vapor. The mechanical test showed core-shell structured nanofibrous scaffolds possessed good mechanical properties but lower than SF/P(LLA-CL) blended nanofibrous scaffolds.