Fabrication of Electrospun Thai Silk Fibroin-Polyethylene Oxide Nanofiber

Dental tissue engineering has gained interest as a promising strategy for substitution and restoration of lost dental tissue in recent years. Three key factors in tissue engineering are cells, scaffold and signaling factors. Objective: To fabricate a naturally-derived biomimetic scaffold from Thai Bombyx Mori silkworm fibroin (Thai SF) using the electrospinning method. Methods: Thai Domestic Silk (Nang Noi Srisaket I strain) was boiled twice in Na2CO3 at 100°C for 30 mins and dissolved in CaCl2:C2H5OH:H2O (1:2:8 in mole ratio) at 70°C for 6 hrs. The solution was then dialyzed, lyophilized to yield SF powder. The 20, 25 and 30% SF solutions in 98% formic acid were prepared. Five percent (w/v) of polyethylene oxide (PEO) was then added to the solution at the ratio of 4:1 (SF:PEO) just before electrospinning at 10 mA, 9 kVp, at 0.5 mL/hr (distance to the 1800 rpm-rotating collector of 12 cm). Electrospun fibers were observed under SEM at 5000X. Fiber diameters were determined using an image analysis software. Results: The fiber diameters of 20, 25 and 30% SF were 400.72±111.28, 394.85±168.78 and 126.63±77.88 nm respectively. At low concentrations, large but uniform fibers were obtained. At 30% SF, however, very fine fibers were formed with beads and branchings in some areas. Conclusion: Nanofibers could be fabricated from Thai SF-PEO and this may be a candidate for making of the biomimetic scaffold in the future for dental tissue regeneration.