Histological evaluation of NHEK cell sheets on type I collagen gels. (A) Cell sheets weighed down on the collagen gel for 10 or 60 min were stained with HE. Gaps between the cell sheet and the collagen gel were notable in the sample weighed down for 10 min, whereas they were not present in the sheet weighed down for 60 min. (B) Anti‐type I collagen antibody staining was used to visualize the adhesion interface between the cell sheet and the gel. The cell sheet was weighed down for 60 min and then incubated for 1 day at 37 °C. (C) Immunohistochemical analyses of NHEK cell sheets before (left column) and 1 day after (right column) grafting. Collagen gels beneath the grafted cell sheets were not clearly visible (right column). Expression of vimentin, β‐catenin, E‐cadherin, Integrin β4, and P‐MLC is shown. The percentage values of HP, P, LP, and N are shown alongside each image. The final determination of the expression levels of the target proteins is presented in bold letters.