Electrohydrodynamic processing of the solutions
The solutions were processed using a Fluidnatek® LE-10 electrospinning/
electrospraying apparatus, equipped with a variable
high voltage 0e30 kV power supply, purchased from BioInicia S.L.
(Valencia, Spain). Solutions were introduced in a 5 mL plastic syringe
and were pumped at a steady flow-rate through a stainlesssteel
needle (0.9 mm of inner diameter). The needle was connected
through a PTFE wire to the syringe, which was placed on a
digitally controlled syringe pump. Processed samples were
collected on a stainless-steel plate connected to the cathode of the
power supply and placed horizontally with respect to the syringe.
The processing parameters were empirically optimized for each
gelatin concentration in order to attain stable electrospraying
avoiding dripping of the solution. Briefly, the flow rate varied from
0.15 to 0.5 mL/h and the voltage was maintained within the range
15e28 kV. The distance between the tip of the syringe and the
collector was 10 cm in all cases.