Fig 1: Histological evaluation of the epidermis of the human skin substitutes and native human skin control. The histological features of the epidermis human skin substitutes developed after 7, 14, 21 and 28 days and human controls (CTR) were evaluated with Hematoxylin-Eosin (HE) and DAPI, as well as with key epithelial markers using immunohistochemistry techniques for PANCK, CK5, CK10 and FLG. The thickness of the epidermis, the number of epithelial cell strata and the immunohistochemical positive expression were quantified and shown accordingly. Statistically significant differences between groups are labeled with asterisks (*), whereas non-significant differences are labeled with “ns”. Scale bar = 200 µm and 26 µm in the insets.