Fig. 4
Effects of Co3O4-NPs on spontaneous cell contractions. a) Representative traces of spontaneous contractions (SCs) occurring in CTRL (top) and NPc50 (bottom) cardiomyocytes during 60 s recordings, after a 60 s conditioning pacing at 2 Hz. The arrow indicates a SC whose amplitude is comparable to an electrically induced twitch; b) mean values ± SEM of the percentage of cells exhibiting SCs in the three groups; *, p< 0.05 (chi-Square test); c) mean values ± SEM of the number of SCs per cell in CTRL (n=42), NPc5 (n=47), and NPc50 (n=50); *, p< 0.05 vs CTRL (one-way ANOVA)