Fig. 5

Representative bright-field and fluorescence microscopy images displaying qualitative assessment of osteogenic differentiation capacity of hMSCs post ejection, after culturing in bipotential ‘mixed’ media for 21 days. To assess the degree and distribution of mineralisation of the ECM, the last stage of osteogenesis, samples were observed using dissection and bright-field microscopy (10×), in addition to staining with Alizarin Red S (10×) and OsteoImage™/PI (5×). Cells exhibiting typical adipocyte morphology depicted in bright-field microscopy images using arrows (scale bars = 50 μm). Red represents calcium deposition stained using Alizarin Red, and green depicts hydroxyapatite nodules stained using OsteoImage™. Ctrl control, PBS phosphate buffer saline, CMC carboxymethyl cellulose, ECM extracellular matrix, PI propidium iodide