Fig. 2

In vitro clonogenicity, morphology, and growth kinetics of MSCs. Clonogenicity of BM-MSCs a and AT-MSCs a′ determined by a colony forming unit-fibroblast (CFU-f) assay (n = 3 independent cultures/group). b CFU-f counts quantified as a percentage of the total viable cells seeded. c-d′) Morphological subpopulations exhibited by BM-MSCs c-c′) and AT-MSCs d-d′ in culture. MSC morphology defined according to the presence of long thin spindles (‘spindle’: c-d or flat cells with atypical processes (‘flat’: c′-d′) (scale bar = 50 μm). e Quantitative analysis of MSC morphological types. Data expressed as a percentage of the total cell number in each population (n = 6 independent cultures/group). f) The population doubling level (PDL) of proliferating MSCs recorded at 3, 7 and 14 days after seeding (n = 3 independent cultures/group/time point). **p < 0.01, ***p < 0.001, ****p < 0.0001. MSCs mesenchymal stem cells, BM-MSCs bone marrow-derived mesenchymal stem cells, AT-MSCs adipose tissue-derived mesenchymal stem cells