A calculated weight of oxidized alginate and N,O-carboxymethyl
chitosan were dissolved into 20 ml distilled water to form 6% (w/w)
and 4% (w/w) solutions, respectively. The solutions were filtered
and stored at 4 ◦C overnight for the further usage. Auto gelling
solutions were prepared as follows: 2 ml of N,O-carboxymethyl chitosan
and oxidized alginate solutions with weight ratio of 1:2 were
mixed at room temperature with gentle stirring to form homogeneous
solution. After that, the auto-gelling solution was placed at
37 ◦C for 30 min to form the N,O-carboxymethyl chitosan/oxidized
alginate hydrogel.