Figure 5: Transmission electron micrographs showing exosomes in an adult mouse heart. (a) Exosomes (asterisks) located at the cell surface of a cardiomyocyte (CM). The latter extends thin cytoplasmic processes (arrow) that encircle the exosome. Inset: higher magnification view showing dense nanostructures (arrowheads) at the interface of the CM membrane and the membrane of the exosome, suggesting involvement of molecular interactions in exosome uptake by CMs. (b) Exosomes (asterisks) encircled by cytoplasmic processes (arrow). (c) Exosomes (asterisks) taken up by the CM within small, round cytoplasmic structures (arrows).