A quiet analytical research laboratory at night, racks of glass vials along a dim bench.

Exosomes and Extracellular Vesicles

Exosomes are small extracellular vesicles, typically under 200 nm, released by cells and carrying proteins, lipids and RNA. No exosome product is approved as a medicine by the FDA, EMA or Health Canada, and the practical problem for any formulator is keeping a fragile lipid vesicle intact and characterized from production to use.

What exosomes are

Extracellular vesicles (EVs) are membrane-bound particles shed by virtually every cell type. Exosomes form inside multivesicular endosomes and are released when those endosomes fuse with the plasma membrane; microvesicles bud directly from the membrane. Because the two overlap in size and markers, the International Society for Extracellular Vesicles recommends the neutral term "small EVs" unless biogenesis is demonstrated. Cargo includes tetraspanins (CD9, CD63, CD81), heat shock proteins, lipids and microRNA. Source matters: mesenchymal stem cell, platelet, milk and plant-derived vesicles differ in composition, and plant-derived nanovesicles are not exosomes in the strict mammalian sense.

Regulatory status

In the United States, EV products intended to treat or prevent disease are regulated as biological products under section 351 of the Public Health Service Act and need an approved biologics license; none has one. The FDA has issued public warnings about unapproved exosome products marketed by clinics. In the EU, therapeutic EVs fall under medicinal product law. In cosmetics, vesicle-derived ingredients (commonly plant-derived or cell-culture conditioned media fractions) are sold in Korea and elsewhere as cosmetic ingredients, with claims limited to appearance. Human-derived material raises separate cosmetic restrictions in the EU, where substances of human origin are prohibited in cosmetics.

Evidence tier

Evidence for therapeutic effects of EVs is predominantly in vitro and in animal models, with a small number of early-phase human trials. Reproducibility is the central weakness of the field: isolation method (ultracentrifugation, size-exclusion chromatography, precipitation, tangential flow filtration) changes purity and yield, and many products are poorly characterized for particle count, protein contaminants and vesicle integrity. MISEV guidelines set minimum reporting requirements for exactly this reason. For cosmetic use, published data are largely manufacturer studies of appearance endpoints. Any partner program should begin with characterization, not claims.

The delivery problem

An exosome is already a carrier, so the formulation question is preservation rather than encapsulation of a payload. EVs aggregate, fuse and lose cargo under freeze-thaw cycling, shear, pH shifts and surfactants, which rules out many standard cosmetic and supplement bases. Lyophilization with sugars such as trehalose helps but does not fully prevent size drift. Topically, a 100 nm vesicle does not cross intact stratum corneum in meaningful quantity, so claims of dermal delivery need penetration data. Stability, shelf life and dose definition (particles per milliliter) are unresolved for most commercial products.

Key facts

The ISEV recommends the generic term "extracellular vesicle" and operational terms such as "small EVs", with size ranges defined by the authors, when biogenesis is not demonstrated (Welsh et al. 2024, J Extracell Vesicles 13:e12404)
No exosome or EV product holds FDA approval; EV products for disease treatment are regulated as biologics requiring a biologics license (FDA Consumer Alert on Regenerative Medicine Products Including Stem Cells and Exosomes, 2020)
Isolation method changes EV purity, yield and characterization, which drives poor reproducibility across studies (Théry et al. 2018, J Extracell Vesicles, MISEV2018)
Substances of human origin are prohibited in EU cosmetic products (Regulation (EC) 1223/2009, Annex II entry 416)

How our delivery technology applies

Here the multi-layer shell is a protective housing, not a payload carrier. A biopolymer outer layer can buffer the vesicle against surfactants, pH shifts and shear in a finished base, and a sugar-rich inner matrix can act as a lyoprotectant during drying. The measurable endpoints are vesicle size distribution, particle count and marker retention before and after encapsulation and across shelf life. We treat EV stabilization as a feasibility question for plant-derived and cosmetic-grade vesicles only.

Send your vesicle source and characterization data to scope a stability feasibility study.