Mechanism of endocytosis of anti-ICAM NCs by BBB cells. (A) Uptake of anti-ICAM NCs by TNFα-activated human brain astrocytes (ACs), endothelial cells (ECs), or pericytes (PCs) was tested after 3 h incubation at 37°C in the presence of con trol cell medium or medium containing inhibitors of CAM-mediated endocytosis (amiloride), caveoli (filipin), or clathrin-coated pits (monodansylcadaverine, MDC). Surface-bound (arrowheads) vs. internalized nanocarriers (arrows) were visualized as described in Fig. 3 and compared to control conditions. Data are mean ± SEM. *Comparison to control (no inhibitor) condition for each cell type (p<0.05 by Student’s t-test). (B) The effect of endocytic inhibitors on the uptake of anti-ICAM NCs by TNFα-activated ECs is shown. Scale bar = 10 μm.