Figure 7
Energy dependence of NP internalization. A. 3D reconstruction of a confocal analysis of cells exposed to NPs and NaN3 for 4 h. Staining of the cells is as follows: Blue - DAPI-stained nuclei, Red – TRITC-phalloidin-stained actin filaments, Green – FITC-labelled SiO2 NPs. Scale bar shows 10 μm. B. The same field of the confocal image shown in the Figure 7A presented as a projection of all images acquired in the stack. C. 3D reconstruction of x,z and y,z-slices of the corresponding regions of the image 7A. and D and E. Cells were either pre-incubated at 37°C with 100 mM of NaN3 for 30 min, or incubated at 4°C before being exposed to NPs at 5 μg/cm2 for 4 h. Quantification of 50 nm-FITC–SiO2 uptake was performed by flow cytometry after addition of TB (D). Analysis of the internalization of 100 nm-Por-SiO2 NPs was performed by imaging flow cytometry using a mask eroded for 3 μm. Representative fluorescence images of cells are shown. Results are expressed as mean value of the percentage of inhibition of NP uptake (D.) or mean value of Internalization score (E.) ± SD, n=3 at least.