Clinical Applications of Extracellular Vesicles: Promises and Pitfalls

Extracellular vesicles (EVs) are membrane-bound nanoparticles released by almost all cell types into the extracellular space, acting as important mediators of intercellular communication by transferring proteins, lipids, and nucleic acids horizontally. EVs are generally classified into small EVs (<200 nm), medium/large EVs (>200 nm), microvesicles, and apoptotic bodies, with current classification methods focusing on physical properties, molecular composition, and cellular origin, as detailed in the MISEV2023 guidelines. EVs are highly promising for diagnostic and therapeutic applications due to their intrinsic biocompatibility, stability in biological fluids, capacity to carry diverse molecular cargo, and potential for drug delivery and functionalization to enable targeted delivery and tissue repair. This narrative review discusses the emerging roles of EVs across various medical fields, including obstetrics and gynecology, ophthalmology, otorhinolaryngology, urology, oncology, orthopedics, neurology, immunology, wound healing, chronic pain management, dermatology, and cardiology. In each discipline, EVs show potential as biomarkers for diagnosing physiological or pathological conditions and as carriers for targeted drug delivery and regenerative treatments. Exosomes, a major type of small EVs, have especially attracted attention as versatile nanocarriers for precision medicine. However, translation into clinical practice requires addressing key pitfalls, including the standardization of isolation and characterization protocols, dose definition, GMP-compliant large-scale production, and regulatory approval. Ongoing interdisciplinary collaboration across disciplines and thorough clinical testing will be essential to unlock the full biomedical potential of EVs and establish them as transformative tools in personalized healthcare.