2.5. Synthesizing cross-linked FCA/COSs scaffold
Scaffold consisted of FC and SA was initially fabricated by blending
and freeze drying technique. COSs were added subsequently in
the second stage of cross-linking. Initially, SA was dissolved in dH2O
at 60◦C to obtain 3% (w/v) solution and FC in 0.02 M acetic acid at
4◦C to obtain 0.8% (w/v) solution. FC was then neutralized by 2 M
NaOH in 1× PBS and both FC and SA solutions were initially well
mixed at 4◦C using homogenizer for 5 min and thereafter mixed for
two days under continuous string using magnetic stirrer to obtain
clear solution with the ratio of 70: 30 (w/w) of collagen to alginate.
The blends were then centrifuge at 3000 rpm for 15 min to
discharge air accumulated in the blend solution. Resultant mixture
was loaded into cell culture plates depending on the destination of
the scaffolds by avoiding air bubble trap in solution. After that, the
molded FCA blend solution was kept at 25◦C for 12 h allowing collagen gelation and freeze first at −20◦C, subsequently at −80◦C for 12 h per each. Freeze dried blend was lipolyzed to result FCA blend