Fig. 1
Scaffold characteristics and cell distribution in culture with hADSCs at different time points. a Stereomicroscopic image of the dry scaffold, showing sponge-like uniform porous structure. b Scanning electron microscopy images of chitosan scaffolds before and (c) after incubation with medium (cell-free blank). Image in B was used for pore size determination. Images d-s demonstrate cellular growth on days 1 (d-g), 7 (h-k), 14 (l-o) and 28 (p-s), the first two images showing growth with hTGF-β3 only, the second with hTGF-β3 + hBMP-6. Grey-scale images (first and third column) are SEM images, fluorescent images (second and fourth column) are live/dead stain with green = Calcein AM for live and red = Ethidium bromide for dead cells. Collagenous fibrous matrix (black arrows) (h-k) For (a) magnification was set at 4x; SEM magnifications were set at 100x (b), 300x (c, d, h, j, l, p, r), 1.10Kx (f, n); Live/Dead magnifications were set at 10x (e, g, i, k, m, o, q, s)