Exosomes are touted as a trendy cure-all. We don’t know if they work.

We do know that exosomes are tiny particles that bud off from cells and that their contents can fluctuate vastly, relying on the supply of the cell (some well-liked choices embrace human umbilical cords, salmon testicles, and roses) and the way wholesome or pressured it’s. Even cell biologists can’t agree on what, precisely, is inside them, and the way helpful—or harmful—these contents could also be.  

The world of exosome therapies is being likened to a “Wild West” by some researchers. Rigorous trials haven’t been performed, so we don’t know the way protected it’s to spray on or inject these tiny thriller blobs. Exosome merchandise haven’t been authorised by regulatory businesses within the US, UK, or Europe, the place the therapies are rising in reputation. Nor have they been approved for medical uses in Japan or South Korea, two different nations the place exosome therapies are well-liked. Nonetheless, “exosomes have emerged as a type of panacea for nearly every thing,” says Leigh Turner, a bioethicist and public well being researcher on the College of California, Irvine, who tracks direct-to-consumer advertising of unapproved well being merchandise. “Dangers are generally minimized, and advantages are generally exaggerated.”

This hasn’t stopped prospects from flocking to the rising variety of aesthetic facilities, stem-cell clinics, and medspas providing exosome therapies, hoping for a miracle repair. The worldwide marketplace for exosome skin-care merchandise was valued at $256 million in 2023 and is forecast to develop to $674 million within the subsequent six years. 

Thriller blobs

Technically known as vesicles, exosomes are made inside cells earlier than being launched. They’ve lengthy been mysterious. The time period “exosome” was launched within the Eighties. Earlier than that, tiny particles that at the moment are thought to have been exosomes had been described as “platelet dust” or “matrix vesicles.”  

At first, scientists assumed that exosomes functioned as trash luggage, shuttling waste out of the cell. However research in 1996 prompt that exosomes may also work to assist cells talk by delivering alerts between them. If a cell is dying, as an example, it might maybe ship a sign to neighboring cells, giving them an opportunity to provide extra protecting substances with the intention to save themselves from the identical destiny. Most cancers cells, alternatively, might doubtlessly use exosomes to ship alerts that co-opt different cells to assist the expansion of a tumor. Nonetheless, it’s not totally understood what alerts are literally being despatched.

One other main thriller is what, precisely, is inside exosomes. “It relies upon who you ask,” says James Edgar, who research exosomes and related vesicles on the College of Cambridge, UK. Cell biologists agree that exosomes include proteins, lipids, and different molecules that consequence from cell metabolism. Some imagine in addition they include DNA and RNA, however not everyone seems to be satisfied. “It’s simply very tough to show or disprove,” says Edgar.

That’s partly as a result of exosomes are so small—solely about 70 nanometers huge, round one-hundredth the scale of a purple blood cell. Whereas the primary photos of them were published in the 1970s, we nonetheless don’t even know for positive what they appear to be; Raghu Kalluri at MD Anderson Most cancers Heart in Houston and his colleagues are finding out the form of exosomes to determine if they’re spherical, oval, or rod-like, for instance.