Extracellular Vesicles: Recent Advances and Perspectives

Extracellular vesicles (EVs) are nanoscale, membrane-enclosed structures that are secreted by nearly all cell types. EVs include small EVs (exosomes), large EVs (microvesicles), and apoptotic bodies, which are distinguished by their biogenesis and size. EV biogenesis involves endosomal pathways or direct budding from the plasma membrane, influenced by cellular states and external stimuli. The complex composition of EVs, proteins, lipids, RNA, DNA, and metabolites reflects their cell of origin, enabling EVs to mediate intercellular communication. EV uptake by recipient cells occurs via endocytosis, membrane fusion, or receptor-ligand interactions, influencing diverse physiological and pathological processes. Indeed, the biological roles of EVs range from immune modulation to tissue repair and contributions to cancer, neurodegeneration, musculoskeletal pathologies, and other disorders. Advances in isolation methods, including ultracentrifugation, size exclusion chromatography, and immunoaffinity techniques, have improved the purity and yield of EVs. Characterization technologies, such as nanoparticle tracking analysis, electron microscopy, and omics approaches, provide insights into their heterogeneity and functional cargo. Thus, EVs hold promise as non-invasive biomarkers for disease diagnosis and prognosis, offering high specificity and stability. Furthermore, the natural biocompatibility, ability to cross biological barriers, and capacity for functional cargo delivery of EVs position them as therapeutic tools and drug-delivery vehicles. Some of the most promising fields of application for EVs include cancer, neurodegeneration, and joint diseases; however, challenges remain in scaling production, achieving targeted delivery, and ensuring regulatory compliance. This review highlights recent advances in EV biology, isolation, and applications, emphasizing their crucial potential in precision medicine while identifying knowledge gaps and future research directions.