Fig. 7
Correlation of the uptake of silver into differentiated Caco-2 cells on the bottom and wall of cell culture dishes after 24 h of incubation and comparison with the in silico-calculated delivered dose of silver nanoparticles. The incubation volume was 500 μL which equals a medium height of 4.5 mm in the insert. Therefore, 1.12 cm2 cell monolayer on the bottom and 1.688 cm2 cell monolayer on the wall are covered with cell culture medium. To determine the uptake of silver into the cells, we used element analysis by AAS subsequent to several washing steps aimed at the removal of particles loosely bound to the outside of the cells (see methods section for details). (a) Calculated delivered dose of the silver nanoparticles under serum-containing (DMEM + 10% FCS) and serum-free (DMEM + 1% ITS) cell culture conditions using the 3DSDD model. (b) Experimentally determined silver content of differentiated Caco-2 monolayers after 24 h of silver nanoparticle incubation. Loosely bound particles and ions were rinsed off prior to measurement of silver content and are thus not incorporated in the bars. (c) Experimentally determined silver amount from silver nanoparticles in Caco-2 cells, presented as the percentage of in silico-calculated delivered dose of the used particles. Mean and standard deviation are calculated from at least three replicates