Extracellular Vesicles for Drug Delivery and Theranostics .

Extracellular vesicles (EVs) are lipid bilayer-enclosed nanopouches generated by all cells and are abundant in various body fluids. Depending on the parent and recipient cells, EVs exchange diverse constituents including nucleic acids, proteins, carbohydrates, and metabolites. Morphologically, EVs suffer from low zeta potentials and short circulation times, but they also offer low intrinsic immunogenicity and inherent stability. Some crucial factors for the effective clinical application of EVs include controlling immune system clearance, achieving the large-scale production of EVs with efficient quality control, and determining the dominant mechanism of the action of EVs. In this Perspective, we shed light on how these intriguing nano-objects are utilized in cellular imaging and drug delivery for disease therapeutics. We also discuss potential strategies for overcoming the associated limitations.