Fig. 3

Effect of PEMF-induced conditioned media (CM) from 3D cultured MSCs on chondrogenic differentiation of MSCs. MSCs in 3D culture were subjected to PEMF exposure at different intensities and durations. The generated CM was collected 24 h post-PEMF exposure and tested for chondrogenic effect over naive (unexposed) MSC pellet cultures undergoing chondrogenic differentiation in the absence or presence of TGFβ. a Real-time PCR analysis of cartilaginous and hypertrophic marker expression after 7 days of differentiation normalized to GAPDH and presented as fold-changes relative to levels in undifferentiated MSCs. The expression of hypertrophic markers was presented as the ratio to Col 2 expression. b Quantification of cartilaginous extracellular matrix macromolecules generated by the differentiated MSCs (+TGFβ) after 21 days of differentiation. Data shown represent means ± SD, n = 6 from 2 independent experiments. * denotes significance differences compared to non-PEMFed (CCM, 0 mT) controls (red dash lines or red bars). # denotes significance differences compared to PEMFed CM (PCM) generated at 2 mT, 10 min