Figure 4

Histological aspect of the skin regeneration after 11 and 21 days of treatment. Panel 1 after 11 days treatment with autologous ASCs, the epidermis was entirely regenerated and almost completely differentiated, with a thin stratum corneum (arrow) and some shedding of necrotic material (asterisk). The dermis contains a small number of inflammatory cells and some small blood vessels. Panel 2 after 21 days treatment, the skin was completely regenerated, with a perfectly differentiated epidermis. Panel 3 allogeneic ASC-treated wounds after 11 days display large areas devoid of epithelium or with a mono-layered or thin epidermis. Panel 4 after 21 days the epithelium was multi-layered, but no stratum corneum is evident. Connective tissue showed a small amount of inflammatory infiltration, with several dilated vessels. Panels 5, 6 the wounds inoculated with BM-MSCs show large areas devoid of epithelium after 11 days, as well as 21 days of treatment. Panels 7, 8 only early signs of re-epithelization are detectable in saline-treated samples; in correspondence with the de-epithelized area the connective tissue is infiltrated by numerous inflammatory cells (granulation tissue) and many vessels appear dilated. Haematoxilin and Eosin staining. Scale bar 200 μm; original mag. ×100.