Fig. 1.

MSC arrangement and phenotype in 2D or 3D substrates. (A) SEM images of 2D or 3D substrates and relative frequency histogram showing the equivalent circle diameter (ECD) of pores in 3D substrates. (B) Left panels: SEM images showing cell morphology in 2D or 3D substrates. Right panels: Confocal maximum projections of glutaraldehyde fixed cells (red) and the underlying surface detected by reflection. Confocal vertical (XZ) sections of the samples are shown at the bottom of the images. Dashed lines indicate the lines along which vertical sections were recorded. Insets in SEM images show higher magnification views of boxed areas. (C) Analysis of the undifferentiated stem cell markers Sox-2 and STRO-1 in MSCs cultured in 2D or 3D substrates. (D) ALP activity in MSCs seeded in 2D or 3D surfaces and cultured in growth or osteogenic medium. In these experiments, a relative activity value of 100 corresponded to about 1.5 ± 0.4 nmol/min.μg of total proteins. Each value represents the mean ± SD of five independent experiments. *p < 0.05 compared to 2D settings (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.).