2.2. GOSA/RGOSA Scaffold Fabrication and Preparation
The graphene-based composite scaffolds were fabricated by a technique
involving solution mixing, freeze-drying, crosslinking, and
bio-reduction as described previously [24]. Briefly, 2 wt. % sodium
alginate powder was dissolved in deionized water until a transparent
solution is obtained. Then, GO (synthesized by modified hummers’ method
as described earlier [34]) was added to the solution to get a final
concentration of 0.5 and 1 wt. %. The mixture was frozen overnight at
-18 °C and fabricated into a porous structure by the freeze-drying
technique. The obtained aerogels were crosslinked in 1 M calcium
chloride (CaCl2) solution for 1 hour and freeze-dried
again to form GOSA scaffolds. The obtained scaffolds are named as
GOSA0.5 and GOSA1 according to the concentration of GO in the composite
sample. SA scaffolds were fabricated without the addition of GO. In
order to make conductive RGOSA scaffolds, the obtained GOSA0.5 and GOSA1
scaffolds were treated with gelatin solution (1 mg
mL-1) at 95°C to produce conductive RGOSA0.5 and
RGOSA1 scaffolds, respectively. The prepared scaffolds were cut in 2 mm
thickness (diameter ≈14 mm) until further use. Details on the
physicochemical characterization of the GOSA and RGOSA scaffolds can be
found in [24].