Intracellular calcium cycling in hiPSC-CMs.

A) Line-scan images and temporal profiles of Fluo-4 fluorescence of hiPSC-CMs seeded on flat plate or on aligned nanofiber-coated coverslips. Ca+2 transients were evoked by electrical field stimulation at 0.5 Hz. B) Summary graphs showing average data for Ca+2 transient amplitude, time to peak and exponential decay constant (τ) of Ca+2 transients recorded in cells from flat plate (Flat, n = 10) and aligned nanofiber (Nano, n = 14) groups, respectively. *P<0.05 vs standard flat plate group. HiPSC-CMs cultured on aligned nanofibers have faster calcium cycling rate and higher contraction frequency than cells maintained on a flat surface.