Fig. 7

Late-stage osteogenesis of synovium, marrow, and adipose cMSCs. Passage 2 cMSCs were cultured in triplicate wells in CCM or ODM with media exchange twice weekly. a After 21 days of culture in CCM (left column) or ODM + 200 ng/ml of rhBMP-2 (middle and right columns) monolayers were fixed in 10% formalin and stained with ARS. Plates were photographed (left and middle columns) and imaged with 10× objective light microscopy (right column) to document ARS accumulation (bar = 125 μm). b ARS extraction (mean ± SD) for a representative donor. ****Significant differences between treatment groups (p < 0.0001). c Mean ± SD ARS extraction values for all 15 cMSC preparations. CCM values were subtracted from osteogenic values to facilitate presentation of results. Data are reported in descending order for each tissue. For b and c, a, b denote significant differences between tissue sources of cMSCs, if present (p < 0.0001). ARS Alizarin Red stain, BMP-2 bone morphogenic protein-2, CCM complete culture medium, ODM osteogenic differentiation medium