Fig. 2.

Functional studies of doxorubicin-exposed hiPSC-CMs using the xCELLigence RTCA Cardio system. a The representative graph displays doxorubicin repeated exposure induced cytotoxicity showing a decrease in normalized Cell Index values. In the graph, DOX-SE indicates doxorubicin single exposure and DOX-RE represents doxorubicin repeated exposure. Cell Index normalization was performed at a Cell Index value of 7.0. The numerical data represent means ± standard deviations (SD) (n = 3). b Influence of single and repeated doxorubicin exposures (156 nM) on cell density and morphology. The scale bar represents 50 µm. c Doxorubicin single and repeated exposures induced changes in % beating rates. Basal beating rate of cardiomyocytes was from 25 to 32 per min at threshold 10. Data show the mean ± SD (n = 3). ***Indicates p value <0.005. d Representative 12 s beating traces of hiPSC-CMs after doxorubicin single and repeated exposures and during drug washout. In each graph Y-axis represents normalized Cell Index (Nor. CI). Beating activity illustrates the development of arrhythmic beating upon repeated exposure and also in surviving cells after repeated exposure. e In contrast to single exposure, repeatedly exposed cells showed a significant decrease in beating amplitude when compared to control cells. Bar graph numerical values represent mean ± SD (n = 3). ***Indicates p value <0.005