Confocal microscopy images
showing the expression of Connexin-43
(panel A) and the expression of Nkx 2.5 (panel B) in HL-1 cells in
all culture conditions. (Panels A and B, A1–A4) Cells cultured
on a plastic substrate (CTRL). (Panels A and B, B1–B4) Cells
cultured on untreated glass coverslip (CTRL glass). (Panels A and
B, C1–C4) Cells cultured on APTES-treated glass coverslip (APTES).
(Panels A and B, D1–D4) Cells cultured on a glass coverslip
treated with one layer of GO (GO1). (Panels A and B, E1–E4)
Cells cultured on a glass coverslip treated with five layers of GO
alternated with PEI (GO5). (Panels A and B, F1–F4)
Cells cultured on a glass coverslip treated with one sheet of GO complexed
with PEI (GO1–PEI). (Panel C, A–F) Gap-junction
distribution in HL-1 cultured cells. The expression as intracellular
contact was measured (yellow dots added on images reported in panel
A, A4–F4) on CTRL (A), CTRL glass (B), APTES (C), GO1 (D), GO5 (E), and GO1–PEI (F) confocal
microscopy images. Red fluorescence: Connexin-43 or Nkx 2.5, respectively;
blue fluorescence: cell nuclei, green fluorescence: cytoskeleton actin.
Mag: 20×. Scale bar = 20 μm. (Panels C, histogram G) The
histogram shows the means of cell-to-cell interactions for each experimental
point. *p < 0.01; **p < 0.001;
***p < 0.0001.