Spreading of stem cells on substrates of different rigidities.
(A) Representative fluorescence images of hMSCs on silicone substrates with elastic moduli of 0.5, 16, and 64 kPa. The substrates were coated with collagen I and cells were stained with phalloidin to fluorescently label F-actin. (B) Spreading areas of hMSCs on silicone substrates with different elastic moduli obtained from the analysis of the fluorescence images. Box corresponds to interquartile range of cell spreading areas; black line indicates median value; whiskers show minimal and maximal values. N = 40 cells for each type of substrates. *statistical significance with p < 0.01.