Fig. 5

AC electrical stimulation (ES) influences adhesion of MG-63 cells. A Scanning electron microscopy images (SEM) of control cells, AC stimulated cells, cells in stimulated medium and cells in medium containing 10 μM H₂O₂ after 2 h of treatment. Upper row: adherent cells showing smaller cell area after ES (2000x magnification, detector HE-SE 2, scale bar 10 μm). Lower row: microvilli on the cell surface with no obvious changes in length and number (20,000x magnification, detector Inlens-Duo, scale bar 1 μm). B Cell area of adherent cells after 2 h ES (mean ± s.e.m., n = 4–7 independent experiments, One-way ANOVA with Bonferroni posttest). C Quantification of non-adherent cells 24 h after ES (mean ± s.e.m., n = 4 independent experiments, Wilcoxon matched-pairs signed rank test). D Quantification of non-adherent cells 24 h after ES with 1 mM pyruvate (mean ± s.e.m., n = 4 independent experiments, Wilcoxon matched-pairs signed rank test). E Medium mediated: quantification of non-adherent cells after 24 h in 7 days stored ES medium (mean ± s.e.m., n = 4 independent experiments, Wilcoxon matched-pairs signed rank test). Note that with this setup of 2 h AC both stimulation of cells and medium led to less adherent cells and more non-adherent cells. The addition of 1 mM pyruvate recovered the adhesion during treatment