Figure 1
Micro-XRF observation of TiO 2 -NP accumulation and impact ex vivo and in vivo . In the in vivo experiment, mice were exposed to a single gavage of 12.5 mg/kg TiO2-NPs and sacrified 6 h after the gavage (in vivo); ex vivo explants were exposed for 2 h to 50 μg/mL of TiO2-NPs. Micro-XRF images of cross sections of the gut from the in vivo (A, in vivo) and the ex vivo (A, ex vivo) experiments. Green: phosphorous (P) distribution map and red: titanium (Ti) distribution map. Ti-rich zones are pointed out with arrows. PIXE images of a cross section of the gut from the in vivo experiment (B). Phosphorous (P) and titanium (Ti) distribution maps, with their colour scale. Lymphoid nodule (n.), villi (v.), submucosa (sm.), muscularis externa (me.), lumen (l.). Paracellular permability probed by measurement of FITC-Dextran 4 kDa flux through mouse gut in vivo (C) and through ex vivo explants of the ileum, Peyer’s patches (pp.) and colon (D). Average of eight replicates ± standard error of the mean. Results were considered statistically significant (**) when p < 0.01.