Cells release membrane-enclosed particles into their surrounding fluid on an ongoing basis. These particles are collectively called extracellular vesicles, a category defined by the presence of a lipid membrane and cargo such as proteins or nucleic acids, rather than by a single size or origin. EVs are found in blood, cord blood and most other biological fluids.
Within that category, scientists distinguish particles by how they form inside the originating cell, for example, vesicles that bud from the plasma membrane versus vesicles that originate inside the cell's internal compartments. The 2023 MISEV guidelines from the International Society for Extracellular Vesicles recommend using the general term 'EV' unless a specific biogenesis pathway has actually been demonstrated for the preparation in question, rather than defaulting to a narrower subtype name.
For a buyer evaluating a cord blood-derived or other EV product, 'EV' is the more defensible umbrella term, and any narrower label such as exosome should be backed by characterization data, such as markers, imaging or isolation method, that supports it. Ask the supplier which characterization methods were used and request the underlying data, rather than taking a subtype name at face value. FDA states there are no FDA-approved exosome products; EV and exosome preparations are generally regulated as biologic drugs under section 351 of the PHS Act, and purchase and clinical-use decisions belong to the physician and their own regulatory counsel. These products are not FDA approved or licensed for any disease or condition. Information is for licensed healthcare professionals and is not medical or legal advice.
EV terminology is inconsistent across vendors, so understanding the umbrella term helps a buyer interpret product labels and characterization data correctly.