Fig. 3

Uptake and localization of pre- and post-incinerated uncoated (CloisNa) and organomodified (Clois30B) montmorillonite nanoclay in differentiated THP-1 macrophages in the absence of LPS. Cells were exposed to a 0.6 µg/cm² dose in 6-well plates for 24 h, followed by trypsinization, centrifugation, pellet fixation, sectioning, and imaging under TEM and TEM-STEM. Both bright and dark field detectors were used to collect images and EDS analyses. All nanoclay particles (white arrows) and crystalline silica were confirmed using EDS elemental analysis (n = 3; Additional file 1: Figures S3-7)