Figure 7From: Titanium dioxide nanoparticle impact and translocation through ex vivo, in vivo and in vitro gut epitheliaExposure protocol. Gut cells were grown on semi-permeable transwell inserts then exposed to 50 μg/mL of TiO2-NPs on their apical pole (A). Cells were chemically fixed, embedded in Epon resin and cross sectioned for TEM observation and SR-μXRF imaging (B); or transwell membranes were dissected and deposited on an appropriate sample holder, taking care of preserving epithelial polarity, cryofixed, freeze-dried and analysed for their NP accumulation through global μPIXE/μRBS analysis of the cell monolayer (4 areas of 50 μm×50 μm) (C).Back to article page