Today, we wanted to highlight more progress in a rapidly advancing area of medicine and talk about a new study that uses an exosomes-based approach for stroke treatment that repairs brain tissue.
A stem cell-based approach to treating stroke
Professor Steven Stice from the University of Georgia (UGA) and Nasrul Hoda of Augusta University led the team that developed AB126, a treatment that uses a type of extracellular vesicle known as an exosome. Exosomes are small fluid-filled structures that are created by stem cells and, in the case of AB126, are produced by human neural stem cells.
Essentially, the researchers are isolating the beneficial signals given out by stem cells and using them rather than the stem cells as a therapy. This makes sense, as other cells react to these signals and change their behavior accordingly. We have talked about the therapeutic potential of extracellular vesicles, particularly exosomes, in a previous article.
An exosome can remain hidden in the bloodstream, carry multiple doses, and store and administer treatment, and its small size allows it to cross barriers that cells cannot. This is ideal for delivering therapies to the brain, as it crosses the blood-brain barrier and other checkpoints in the body.
After the administration of AB126, the researchers used MRI scans to assess brain atrophy rates in an animal model of stroke. The scans showed around 35 percent decrease in the size of injury and a 50 percent reduction in brain tissue loss. These results were also replicated by Franklin West, associate professor of animal and dairy science at UGA, in a pig model of stroke.
Within days, the researchers observed improved mobility, better balance, and measurable behavioral benefits in treated animal models of stroke.
Based on the successful results of these preclinical tests, the next step is to take this therapy to human clinical trials by 2019 via ArunA Biomedical, a UGA startup company. The company plans to expand its scope beyond stroke, and preclinical studies in epilepsy, traumatic brain, and spinal cord injuries begin later this year.
This is another example of the recent interest in using extracellular vesicles, such as exosomes, as therapies rather than stem cells themselves. Multiple research groups are now developing these therapies to treat various age-related diseases, so we can almost certainly expect to hear more in the near future.
The use of extracellular vesicles also holds the promise of being more cost-effective from the point of view of storage, logistics, manufacture, and delivery. With the first clinical trials now in the cards for the near future, it will be interesting to see how this develops in the next few years.
 Webb, R. L., Kaiser, E. E., Scoville, S. L., Thompson, T. A., Fatima, S., Pandya, C., … & Baban, B. (2017). Human Neural Stem Cell Extracellular Vesicles Improve Tissue and Functional Recovery in the Murine Thromboembolic Stroke Model. Translational stroke research, 1-10.