Figure 5.

Fluorescence microscopy images of calcein AM-stained fibroblasts grown on hydrogels prepared in KOH 1.5M (a,d,g), Na₂CO₃ 1.5M (b,e,h) or NH_3(g) (from 28% ammonia solution) (c,f,i). All images are at magnification 4 X O.M.; scale bars 500 μm). (a,b,c) cells grown for 4 days migrating from the plate onto chitosan scaffolds. Red circles indicate cells grown in clusters into macropores; (d,e,f) cells grown for 14 days. Red arrows indicate the direction of cell migration on the scaffold. (g,h,i) cells grown for 21 days. In this day differences in cell growth on different scaffolds are less appreciable from microscopic observation. Images in inserts show the picture of the same field taken by contrast phase microscopy, showing the position of scaffolds with the grid structure conferred by 3D-printing.