Fig. 4

In vivo functional assay of HEKs grown on laminin system. a Schematic diagram of the graft site and insertion of silon dressings and graft (with adaptation from Barrandon et al.). b Cross section of the completed graft. c Human epidermis generated by the flap method, harvested 14 days after grafting consists of the (top to bottom) mouse epidermis (m-Ep), dermis (m-D), subcutaneous tissue (SC), panniculus carnosus (PC), connective tissue (CT), and human epidermis (h-Ep). Frozen sections were stained with hematoxylin and eosin. Scale bar = 100 μm. d Thickness measurement of stratified epidermis generated in vivo comparing between laminin culture system (LN-511 and LN-421) vs. 3T3 co-culture system. Dot plot is represented as individual measurement, center line is the means, and whiskers represent s.e.m. (n = 30). e Presence of human epidermis is confirmed by human-specific Ku80 staining. Scale bar = 100 μm. f Characterization of human epidermal basal and differentiation markers expressed on the developed graft. Note that a continuous laminin γ2 chain-containing layer was observed in between the basal human keratinocytes-mouse connective tissue junction, suggesting that the grafted cells expressed laminin-332—signature expression of functional human keratinocytes. Scale bar = 100 μm