Fig. 3: Uptake of CD63⁺A33⁺ exosomes by liver cells depends on exosomal lipid composition.

a Confocal images of GFP-positive exosomes detected in mouse liver after injection of GFP-MC38 epithelial cells into the colon. DAPI was used to stain the nucleus. Each data point was measured in triplicate. b Flow cytometry analysis of PKH-26-labeled exosome uptake by hepatocytes (albumin⁺) and Kupffer cells (F4/80⁺). Filled triangle—L-Exo and filled rectangle—H-Exo. c PKH26-labeled exosomes visualized by confocal microscopy in hepatocytes/albumin⁺/green (yellow arrow) and Kupffer cells/F4/80/purple (white arrow) (Ieft). The percentages of total exosome uptake per cell type are summarized on the right. Scale bar as indicated. Each data point was measured in triplicate. d Flow cytometry analysis of Kupffer cells cultured with PKH26-labeled H-Exo for 16 h in the presence or absence of endocytosis inhibitors (indicated). Percentage of PKH26⁺ Kupffer cells summarized below. e, f PKH-26-labeled nanoparticles were cultured with primary hepatocytes (upper panels, e) and Kupffer cells (lower panels, f). Cells were analyzed by flow cytometry and the percentage of PKH-26-positive cells were assessed after treatment with each nanoparticle summarized at the right. Circle—nanoparticles made up of total lipids of L-Exo; rectangle—H-Exo lipids; upward triangle—H-Exo lipid-depleted PC and downward triangle—L-Exo PC supplemented. Source data are provided as a Source Data file. Data are represented as the mean ± SD. Student’s t test (two-tailed) or one-way ANOVA with a Tukey post hoc test. ** < 0.01; *** < 0.001, and **** < 0.0001.