Fig. 9

The uptake of coumarin-6-(C-6) or FAM-miR139/LPN-HR into Caco-2 cells. a, b Caco-2 cells were treated with a coumarin-6 in various LPNs at pH 7.4 and 6.5 for 6 h or b pretreated with different endocytosis inhibitors for 1 h and then treated with C-6/LPN-HR at pH 6.5 for 6 h. Various endocytosis inhibitors include P-L (adsorptive endocytosis inhibitor), CPZ (clathrin-mediated endocytosis inhibitor), DMA (macropinocytosis inhibitor), and NYS (caveolae-mediated endocytosis inhibitor). Cellular uptake was measured by detecting the relative fluorescence intensity (green fluorescence) using a flow cytometer. a *P < 0.05: compared with C-6/LPN at pH 6.5, ^†P < 0.05: compared with C-6/LPN-H at pH 7.4, ^‡P < 0.05: compared with C-6/LPN-H at pH 6.5, and ^§P < 0.05: compared with C-6/LPN-HR at pH 7.4. b *P < 0.05: compared with C-6/LPN-HR. Values are the mean ± SD (n = 3). c–e The localization of C-6/LPN-HR at pH 7.4 or 6.5 in Caco-2 cells at c 1 h and d 6 h; e Caco-2 cells were treated with FAM-miR139/LPN-HR for 6 h and observed by confocal laser scanning microscope (CLSM). Green: C-6 or FAM-miR139; Red: LysoRed; Blue: DAPI. Magnification: ×90