80 years of extracellular vesicles: from discovery to clinical translation.

Extracellular vesicles (EVs) are heterogeneous, lipid bilayer-enclosed vesicles secreted by cells. Research on EVs dates back to the 1940s, and the term "exosomes" - a major subtype of EVs - was coined in 1981 to describe small membrane vesicles shed from cells. However, it is only in the past two decades that research in this area has expanded rapidly. By transferring functional biomolecules, EVs play a pivotal role in intercellular communication and regulate a wide range of cellular functions under both physiological and pathological conditions. Owing to their high biocompatibility, capacity to protect encapsulated cargo from degradation, and ability to cross biological barriers, EVs also show great promise as biomarkers and drug-delivery systems. Following the first, albeit unintentional, isolation of EVs in 1946, the 80th anniversary of EV research is now approaching. In this review, we trace the history of EV research and summarize key advances in the field. We also discuss current challenges and future prospects in this rapidly evolving area.