Table 2.

The permeability and selectivity of hESC-derived RPE are similar to those of hfRPE in SFM-1

An Ussing chamber with voltage clamp was used to estimate the permeation coefficient of the tight junctions under conditions that inhibit membrane transport. (Under normal conditions, the TEP = 0.8 ± 0.1, apical positive for H9-RPE maintained in KSR.) Measurements were made at 37°C. Cultures maintained in SFM-1 had a higher TER and lower permeation coefficient for the ions examined. The permeation ratios indicate that the selectivity of the junctions was close to that of hfRPE and slightly cation selective, when compared with the bare filter. The indicated SE was calculated from three to four cultures.

Abbreviations: hESC, human embryonic stem cell; hfRPE, human fetal retinal pigment epithelium; KSR, knockout serum replacement medium; RPE, retinal pigment epithelium; SFM, serum-free medium; TEP, transepithelial electrical potential.