Fig. 1.

Schematic illustration of in vivo development and in vitro differentiation of RPE and LESCs. a At early stages of embryonic eye development, surface ectoderm thickens and invaginates together with the underlying neuroepithelium of the optic vesicle. The bilayered optic cup gives rise to the neural retina and the retinal pigment epithelium (RPE), while the lens and corneal epithelium develop from the surface ectoderm [14]. Some of the known signaling pathways affecting the cell fate choice during differentiation, such as bone morphogenetic protein (BMP) for surface ectoderm, are shown. b An overview of the optimized human pluripotent stem cell (hPSC) culture and directed RPE and limbal epithelial stem cell (LESC) differentiation protocols, as well as key media and matrix components used (not to scale). Blebb. blebbistatin, col IV collagen type IV, E8 Essential 8™ Flex Medium, FGF fibroblast growth factor, LN-521 recombinant laminin-521, SB SB-505124 hydrochloride hydrate, TGFβ transforming growth factor beta, XF-Ko-SR Knock-out™ serum replacement XenoFree CTS™