Fig. 2
SA-CNTs facilitate epicardial cells outgrowth from embryonic mouse hearts and guide the migration direction of outgrowing epicardial cells. a-f Representative phase contrast light microscopy images of epicardial outgrowth at Day3 indicating peripheral cells on Coverglass resulted in a formation of “Dam” (indicated with white arrow) which hinders the central cells from moving forward until the cells break through the dam (a-c), whereas this phenomenon rarely observed in outgrowing cells on SA-CNTs (d-f). b, c The enlarged image of a selected zone in (a); (e, f) The enlarged image of a selected zone in (d). g Typical image (stitched from two fields of one heart explant) after 4 day of culture showing that epicardial cells on SA-CNTs tend to migrate along the CNT-aligned direction. The maximum transverse and longitudinal migration distance of cells were measured as La and Lb using ImageJ and shown as La/Lb ratio in (h). h Migration pattern indicated using La/Lb ratio (divide La by Lb) showing that epicardial cells on SA-CNTs have its own unique migration manner due to the superaligned structure of SA-CNTs. n = 7 for control sample and n = 13 for SA-CNTs from 5 independent experiments. *p < 0.05. Scale bars, 500 μm