Fig. 1.
More undifferentiated human pluripotent stem cells grow on chemically optimized substrates than on feeder-containing substrates. (A) Schematic diagram of UV treatment. XPS spectra of surface chemical functionality of an untreated “virgin” polystyrene culture dish (B) and after 2.5 min of UV treatment (C) are shown. Phase-contrast and fluorescence images of transgenic Oct4-GFP hESCs on these surfaces are shown. Bright green fluorescence on the UV-treated areas indicates strong expression of the pluripotency marker Oct4. (D) Relative number of hESC colonies on UVPS treated for 2.5 min vs. conventional TCPS on day 7 after cell seeding. (E) Colony formation on virgin polystyrene treated with various UV doses. The y axis lists the number of colonies formed on day 7. (Inset) PLS model prediction of the number of colonies plotted against the experimental results. For A–E, surfaces were precoated with 20% (vol/vol) bovine serum and cells were seeded in ROCK inhibitor for the first 8–12 h. (F) Using the PLS model of the ToF-SIMS data, surface ions with high positive or negative regression coefficients were identified as supporting or inhibiting hESC colony formation (expanded list is provided in Fig. S3C). (G) Number of adhered cells after 24 h of culture on UVPS coated with either human serum (HuSerum) or recombinant human vitronectin (HuVitronectin) and with the specified integrin-blocking antibody. Blocking with αvβ5 reduced adhesion, whereas blocking with β1 had minimal effect, either alone or in combination with αvβ5 blocking. (H) Number of undifferentiated Oct4-GFP–positive hESCs per well of a six-well plate at day 7 of culture on UVPS (red) and on standard mouse embryonic feeder (mEF)-containing substrates (gray). UVPS was precoated with vitronectin. All error bars indicate 95% confidence intervals (n = 3).