Figure 6.

(A) Contraction features in co-culture spheroids 10 days in culture at different pacing frequencies. The spheroids followed pacing frequencies of 2–4 Hz reflected by the time of the “p-p” parameter since 2 Hz = 500 ms, 3 Hz = 333 ms, and 4 Hz = 250 ms. (B) Spontaneous contractions with spheroid of pure hiPSC-CMs or co-culture spheroids at 1 month in culture. (C) Spontaneous contractions in 2D cultures of hiPSC-CMS or cultures with added CF. N = 4–6 spheroids per group or fields in 2D-cultures, *p < 0.05, **p < 0.01, ***p < 0.001.