The prepared keratin solution was placed in a 5 mL
syringe with a stainless needle tip having an internal diameter of
0.2 mm. The needle tip (cathode) was connected to a high voltage
generator (SL50 Spellman High Voltage Electronics Corporation,
USA) and the polymer solution was electrospun toward a grounded
stainless steel collector (20 cm × 20 cm) using a “bottom up” con-figuration, in which the jet-emitting source was positioned below
the grounded collecto