Fig. 6

Early osteogenesis of synovium, marrow, and adipose cMSCs. Early osteogenesis was determined using the alkaline phosphatase (ALP) activity assay. Passage 2 cMSCs were cultured in CCM, OBM, or OBM + rhBMP-2 for 7 days and evaluated for the ability to convert the colorless substrate PNPP to colorimetric PNP over time. a Kinetic ALP activity results for a single cMSC preparation from a representative donor. ALP activity was determined by spectrophotometer (absorbance 405 nM) over a 20-minute time course. b ALP activity normalized to cell number by DNA quantification for synovium, marrow, and adipose cMSCs from a representative donor, demonstrating the minimal response of adipose cMSCs to OBM or OBM containing rhBMP-2. c Scatter plots demonstrating ALP activity for all 15 cMSC preparations organized by tissue and media condition. Each data point represents the ALP activity per cell for an individual cMSC preparation and a given media condition (bar = mean across the five donors). For b and c, significant differences between treatment groups: *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001. a, b denote significant differences between tissue sources of cMSCs (p < 0.01). BMP-2 bone morphogenic protein-2, CCM complete culture medium, OBM osteogenic basal medium