Figure 6.

The mechanism of cellular internalization was investigated by flow cytometry and confocal microscopy of cells co-incubated with ELP and endocytosis inhibitors at 42 °C. Cellular uptake, as measured by cellular fluorescence, significantly decreased for Arg₅-ELP_BC micelles co-incubated with genistein or amiloride, but not dansylcadaverine (A). This effect was more pronounced for Arg₅-ELP_BC as compared to ELP_BC or Arg₅-ELP controls. This suggests that caveolae-mediated endocytosis and macropinocytosis play important roles in the internalization of Arg₅-ELP_BCs in their micelle state. Confocal microscopy of cells incubated with Arg₅-ELP_BC micelles alone (B), or in combination with dansylcadaverine (C), genistein (D), or amiloride (E) support the conclusions drawn from flow cytometry. Data represents average of 3 experiments ± SEM. Green – ELP; Red – cell membrane; blue – cell nuclei; scale bars 25 μm. Signal from the ELP is shown as a maximum intensity projection, demonstrating cellular uptake throughout the volume of the cell.