Figure 5

Uptake and quantification of exocytosed 70 nm-COOH silica nanoparticles using a cell assay system. HUVEC seeded on flexible membranes were treated for 24 hours with aSNPs under static conditions. NP suspension was removed, cells extensively washed, incubated with fresh medium under flex or static condition for 24 hours. The medium including the exocytosed aSNPs was used to treat HUVEC grown onto 96 well plates for further 24 hours. Afterwards these cells were washed, fixed, and analyzed for internalized aSNPs by image analyses. (A) Representative images of cells that internalized exocytosed aSNPs. Cell nuclei counterstained with Hoechst dye (blue). Scale bar 100 μm. (B) Quantification of relative fluorescent intensity depicted as means of 24 images per condition.