200× optical magnification for all images. (A) HE staining of 5×105 seeded hfKC/cm2, 21 days. (B) Fibroblast and collagen type I distribution, 21 days. Red: Anti-vimentin staining. Green: anti-collagen type I staining. Blue: DAPI. (C) Capillary-like network, 1.25×105 seeded hfKC/cm2, 21 days. Red: Anti-CD31 staining. Green: Anti-laminin staining. Blue: DAPI. (D) 1.25×105 seeded hfKC/cm2, 21 days. Green: Anti-pan-cytokeratin staining. Blue: DAPI. (E) 5×105 seeded hfKC/cm2, 21 days. Green: Anti-pan-cytokeratin staining. Blue: DAPI. (F) HE staining. Bioreactor-cultivated OTSC with 5 mL/min culture media flow. (G) 5 mL/min flow. Red: Anti-vimentin staining. Green: Anti-collagen type I staining. Blue: DAPI. (H) 5 mL/min flow. Red: Anti-involucrin staining. Green: Anti-pan-cytokeratin staining. Blue: DAPI. HE, hematoxylin and eosin; hfKC, human foreskin keratinocytes.