Penetration of nanoparticles in the epidermal cells after application by pulverization. A) Low magnification TEM micrograph showing the epidermal cells. The cell carrying nanoparticles appear labelled by an asterisk (*). The cytoplasm does not show any special feature compared to the underlying parenchymatic cells. B) detail of the region squared in (A), showing the presence of two nanoparticles as dark electron dense spots. Bar in A = 3 μm; B = 500 nm.