Exosomes could also be useful for delivering drug treatments. After all, they’re basically little packets of proteins and other materials that can move between cells. Why not fill them with a medication and use them to target specific regions of the body?

Because exosomes are made in our bodies, they are less likely to be considered “foreign” and rejected by our immune system. And the outer layer of an exosome can serve as a protective layer, preventing the drug from being broken down until it reaches its destination, says James Edgar, who studies exosomes at the University of Cambridge. “It’s a very interesting method for drug delivery,” he says.

Dave Carter is one of the scientists working there. Carter and his colleagues at Evox Therapeutics in Oxford, UK, are engineering cells to produce compounds that could help treat rare neurological diseases. These compounds could then be released by cells from exosomes.

In their research, Carter and his colleagues can change almost everything about the exosomes they study. They can modify their contents by loading them with proteins or viruses or even gene editing therapies. They can modify the proteins on their surface to make them target different cells and tissues. They can control how long exosomes stay in an animal’s circulation.

“I always loved playing with Lego,” he adds. “I feel like I’m playing with Lego when I work with exosomes.”

Others hope that the exosomes themselves have some sort of therapeutic value. Some hope that exosomes derived from stem cells, for example, might have some regenerative capacity.

Ke Cheng of Columbia University in New York is interested in the idea of ​​using exosomes to treat heart and lung diseases. Several preliminary studies suggest that exosomes from the heart and stem cells could help animals like mice and pigs recover from heart injuriessuch as those caused by a heart attack.

Many clinical trials of exosomes are certainly underway. When I searched for “exosomes” on Clinicaltrials.gov, I got over 400 results. However, these are early stage trials and of varying quality.