Fig. 2

Effect of soluble ECMs on human MSCs in 2D culture. a MSCs were cultured up to 7 days on tissue culture plastic in one of six medium conditions. b MTS assay showed that all ECM groups enhanced cell metabolism (proliferation), but urea-extracted fractions were the most mitogenic by day 7. Letters correspond to statistically equivalent groups at a given timepoint. c Gene expression analysis on day 3 suggested tissue-specific bioactivity of urea-extracted ECM fractions (p < 0.05, n = 9). Statistically significant differences are indicated by overlying horizontal lines. d Phase contrast microscopy showed spindle-shaped cells in the tECM group but cobblestone morphology with TGF-β and cECM supplementation. Scale bar = 100 μm. cAP acid-pepsin digested cartilage extracellular matrix, cECM urea-extracted cartilage extracellular matrix, tAP acid-pepsin digested tendon extracellular matrix, tECM urea-extracted tendon extracellular matrix, TGF transforming growth factor