Fig. 3

Multilineage differentiation potential of BM-MSCs isolated from bone samples obtained during PAO and THA. A Representative images of Alizarin Red stained cells following 21 days of culture in expansion medium (EM) and osteogenic medium (OM). Scale bar, 500 µm. B Quantification of the mineral matrix content following Alizarin Red staining at day 14 and 21 of osteogenic differentiation. C Quantification of pNPP consumption indicating ALP activity at day 0 (24 h after osteogenic stimulus), 4 and 7. D P1NP concentration as a marker for collagen I synthesis in cell culture supernatants collected at day 7 of osteogenic differentiation. E Representative fluorescence microscopy of BM-MSCs after staining with NileRed (red, fat droplets) and DAPI (cyan, nuclei) at day 14 of culture in EM and adipogenic medium (AM). Scale bar, 100 µm F Quantification of fat droplets normalized to cell number following NileRed staining at day 10 and 14 of osteogenic differentiation. G Quantification of the spheroids’ surface areas following 21 days of 3D culture without chondrogenic stimulus (−TGF) and with chondrogenic stimulus (+TGF). H Representative images of alcian blue stained sections of spheroids. Scale bar, 250 µm. I Total protein content of spheroids at day 21. J Total proteoglycan content of spheroids at day 21. (K) Total proteoglycan content normalized to total protein content of spheroids. [normally distributed data: mean ± SD; non-normally distributed data: median with IQR; levels of significance: *p < 0.05]