Extended Data Figure 5. Exosome co-localization with specific cell types within target tissues.

a, Immunofluorescence analysis of resident cells in lung, liver and brain after labelled exosome injection. Analysis of exosome (red) co-staining with markers (green) for tissue-specific stromal cell types. Top, representative images of immunofluorescence microscopy of 4175-LuT exosome co-staining with F4/80, CD31 and EpCAM. Middle, liver sections from mice injected with BxPC-3-LiT-derived exosomes were co-stained with CD31, S100A4 and EpCAM. Bottom, brain sections from mice injected with 831-BrT exosome were co-stained with F4/80, S100A4 and EpCAM (n = 3 per experiment for two independent experiments). b, Exosome biodistribution and co-localization with extracellular matrix proteins. Left top, representative immunofluorescence microscopy images of lung tissue, depicting 4175-LuT exosome (red) co-staining with laminin (green). Right top, laminin (green) co-staining with S100A4 (red). Left bottom, representative immunofluorescence microscopy of liver tissue co-stained for fibronectin (green) and BxPC-3-LiT exosomes (red). Right bottom, fibronectin (green) co-staining with F4/80 (red) (n = 3, two independent experiments). Scale bars, 30 μm.