File Name : supporting  figure s1.tif

Caption : supporting figure s1. physico-chemical characteristics of initial nps. observation of np stock solutions in tem and characterisation of nps diluted in dmem/f-12 media by dls (hydrodynamic diameter in nm) and zeta potential measurements (in mv) of (a) 16- (b) 50- (c) 100 nm-sio2-fitc-nps ; (d) 16- (e) 50- (f) 100 nm sio2+-fitc-nps and for (g) 140 nm-tio2-coated sio2-fitc-nps.

File Name : supporting  figure s2.tif

Caption : supporting figure s2. np characterization. (a) drift spectra of the sio2-fitc-nps before and after surface chemical modification by an aminated polysiloxane film or by a thin titanium oxide coating. (b) pz of naked, aminated and tio2-coated sio2-fitc-nps for different ph. arrows indicate the iep of each nanoparticle. grey zones delimitate the ph range of colloidal instability at low ionic strength. these flocculation domains can be expanded for higher ionic strengths. (c) icp-oes elementary analysis of 140 nm-tio2-coated sio2-fitc-nps. the value of si/ti ratios allows estimating the tio2 thickness.

File Name : supporting  figure s3.tif

Caption : supporting figure s3. calu-3 cells viability and release of il-8 in response to np exposure. (a) calu-3 cells were exposed for 24 h to 16- 50- 100 nm-sio2- or sio2+-fitc-nps or 140 nm-tio2-coated sio2-fitc-nps in a concentration range from 0 to 50 µg/cm². metabolic activity was assessed by the wst-1 assay. red line corresponds to control value. data normalization was performed using control values and expressed as percentage of control ± sem, n = 6. *: different from control (p<0.05). (b) calu-3 cells were exposed to 16- 50- 100 nm-sio2 or sio2+-fitc-nps or 140 nm-tio2-coated sio2-fitc-nps at 5 or 10 µg/cm² for 24 h. il-8 protein concentration was assessed by elisa in apical and basolateral culture media. red line corresponds to control value. data were expressed as mean ± sem, n = 3. *: different from control (p<0.05).

File Name : supporting  figure s4.tif

Caption : supporting figure s4. permeability characteristics of the calu-3 epithelial monolayer and trapping capacities after np treatment. (a) calu-3 cells were treated with 16- 50- 100 nm-sio2-fitc-nps at 5 and 10 µg/cm² for 24 h in presence or not of fcs (2%) or dpl (0.004%). teer values were determined before (in white) and after (black bar) exposure. data were expressed as mean ± sem, n = 12. *: different from pretreatment value (p<0.05). (b) after 24 h of treatment at day 14th with 50 nm-sio2-fitc-nps calu-3 cells were maintained in culture until day 21st and fixed for confocal microscopy observations. the (x;y) left images corresponding to the z-projection of a stack of 5 to 10 images. staining of the cells is as follows: blue – dapi-stained nuclei, green – 50 nm-sio2-fitc-nps, red – zo-1 protein labelled with alexa-568-anti rabbit antibody. the (x;y) right images correspond to the z-projection of a stack of 5 to 10 images acquired only by using the green channel for a better observation of 50 nm-sio2-fitc-np distribution inside the cellular monolayer. the scale bar corresponds to 20 μm.

File Name : supporting  figure s6.tif

Caption : supporting figure s6. green fluorescence distribution inside nci-h292 after np treatment or exposure to calu-3 conditioned media. untreated nci-h292 cells (a) or exposed for 6 h to fitc at 1.2 ng/ml (b) or to calu-3 basolateral media after an exposure to 16- 50- 100 nm-sio2-fitc-nps at 10 µg/cm² for 24 h (c) or to fresh 16- 50- 100 nm-sio2-fitc-nps at 10 µg/cm² (d) or to fresh 16- 50- 100 nm-sio2-fitc-nps at the estimated np concentration of calu-3 basal media (ie respectively at 0.86; 1.45; 0.79 µg/cm²) (e) before being rinsed and fixed for confocal microscopy experiments. the (x;y) left images corresponding to the z-projection of a stack of 5 to 10 images. staining of the cells is as follows: blue - dapi-stained nuclei, green – sio2-fitc-nps / fitc, red - phalloidin-stained actin filaments. the (x;y) right images correspond to the z-projection of a stack of 5 to 10 images acquired by using only the green channel for a better observation of sio2-fitc-np distribution inside the cellular monolayer. the scale bar corresponds to 20 μm and white arrows to the np localisation inside the cellular monolayer.

File Name : supporting  figure s7.tif

Caption : supporting figure s7. np uptake by calu-3 cells evaluated by flow cytometry. calu-3 cells were treated with 16- 50- 100 nm-sio2 (in white) or sio2+-fitc-nps (in grey) or 140 nm-tio2-coated sio2-fitc-nps (in black) at 5 µg/cm² for 24 h. after trypsination and addition of 0.11% of trypan blue, the cellular suspension was analyzed by flow cytometry. mfi obtained by analyzing 10,000 cells in the gate allowed quantifying np uptake in function of the size and the composition. data were expressed as mfi ± sem, n = 3. *: different from control (p<0.05); ¤: different from sio2-fitc-nps value (p<0.05).