Fig. 1
Test material sedimentation and uptake by NR8383 rat alveolar macrophages. A Corundum; B Quartz DQ12; C TiO2 NM-105; D CeO2 NM-212; E SiO2.naked; F BaSO4 NM-220; G DPP Orange N; H Graphite nanoplatelets. Phase contrast micrographs show settled particles at the bottom of cell-free wells in 96-well plates (a1–h1 on the left side of the individual images) and corresponding particle-laden NR8383 cells at the end of the 16-h incubation period with the same particle concentration a2–h2 on the right side of the individual images). Note that the uptake of particles (loaded with 90 μg/mL) appears complete as viewed by light microscopy, except for SiO2.naked (loaded with 22.5 μg/mL), where settled particles are hardly visible