Figure 1

Nanoparticle characterization and uptake in macrophages. (a) Characterization of nanoparticles. (b) Schematic illustration of the various pathways of nanoparticle uptake in macrophages. Inhibitors of specific pathways are shown. Cytochalasin D was used as a broad-spectrum inhibitor of actin-dependent uptake. (c) Nanoparticle uptake in macrophages. Suppression of nanoparticle uptake upon exposure to cytochalasin D (bar graph ‘+’) in Raw 264.7, J774A.1, and Kupffer cells. Values are normalized to those of control cells. Data is presented as mean ± s.d. of triplicates. Statistics by Student’s t-test. *P < 0.05; **P < 0.01; ***P < 0.001, compared with control cells. Predominant pathways of nanoparticle uptake in the macrophage cell lines (pie chart). Values are normalized to those of cells treated with cytochalasin D. Other pathways of uptake refer to phagocytosis or clathrin/caveolae-independent endocytosis. PDI, polydispersity index; PEG, polyethylene glycol.