Fig. 3

Effects of Co₃O₄-NPs on cardiomyocytes mechanics and intracellular calcium dynamics. a) Representative traces of sarcomere shortening (left panel) and calcium transients (right panel) recorded in CTRL, NPc₅, and NPc₅₀ groups. Panels b-h: mean values ± SEM of sarcomere shortening (b, FS), maximal rate of shortening (c, −dL/dt_max) and re-lenghtening (d, +dL/dt_max), time of total cycle measured at 90% of re-lengthening (e, T-cycle_90%), and re-lengthening time measured from the peak of contraction (f, T-rel_90%), calcium transient amplitude, expressed as fluorescence peak normalized to baseline (g, f/f₀), and time constant of intracellular Ca²⁺ decay (h, τ) measured in CTRL (73 and 40 cells, for mechanics and calcium transients respectively), NPc₅ (71 and 35), and NPc₅₀ (88 and 21) cells. *, p< 0.05 vs CTRL; #, p< 0.05 vs NPc₅ (GLM-ANOVA for repeated measurements)