Fig. 4.

Different strategies explored for engineering of exosome surface with imaging probe (radioisotope/radiotracer, magnetic nanoparticles, gold, quantum dots, and labelling fluorescent probes), targeting moieties (monoclonal/polyclonal antibodies, aptamer, fragmented antibodies, and other biomacromolecules), conjugating small, biological, macro-/bio-macromolecules (reporter agents and other molecules), and hybrid nanosystems. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)