Understanding extracellular vesicle biology, isolation, and characterization: The theory of EV-erything

Extracellular vesicles (EVs), especially exosomes, are nanoparticles increasingly recognized as key regulators of intercellular communication in both physiological and pathological aspects. Despite rapid progress, inconsistencies in nomenclature, isolation, and characterization continue to restrict translational advancement. This review aims to offer a comprehensive synthesis of EV biology, with a focus on biogenesis, molecular composition, heterogeneity, and methodological considerations for isolation and characterization.

A narrative review of the literature was performed, assessing historical progress, molecular mechanisms regulating EV biogenesis and payload selection, and existing experimental methods for EV isolation and analysis. Moreover, a comparative analysis of classical and emerging isolation approaches was conducted.

EVs are shown to carry diverse bioactive cargo, such as proteins, lipids, and nucleic acids, allowing modulation of cascades implicated in immunity, tissue regeneration, and disease progression. Considerable variability exists across EV subpopulations, complicating categorization and functional attribution. Isolation techniques demonstrate unique trade-offs between scalability, yield, purity, and functional integrity, with no universally optimal strategy. Crucially, methodological selection is highly based on downstream applications, with therapeutic and diagnostic uses necessitating fundamentally varying performance criteria.

EVs serve as dynamic signaling systems with significant therapeutic and diagnostic potential. Advancing the discipline needs standardized techniques, enhanced classification platforms, and context-specific optimization of isolation approaches. A deeper comprehension of EV biology and methodological rigor will be necessary to unravel their full application in precision medicine.