Study shows stem cell therapy for ischemia can be optimized

When blood flow is reduced or cut to tissues, cells are deprived of oxygen and nutrients, which can lead to cell death if blood flow isn’t efficiently restored. This serious condition is known as ischemia.

Stem cells are promising treatments, but they tend not to stay at the site or survive long enough to heal the damage.

Ohio State University Biomedical Engineering Professor Shawn He, Internal Medicine Professor Zhenguo Liu and colleagues recognized that in order to improve the viability of stem cell treatments for ischemia, it was crucial to continuously deliver molecules like growth factors to help the stem cells survive and develop into new blood vessels. Nanoparticles are good at this sort of biomolecule delivery, but they tend to drag the cargo inside cells. To treat ischemia, the growth factors need to stay outside the cells.

To address that issue, the researchers encapsulated a growth factor inside nanoparticles to protect them from degradation, and then placed the nanoparticles inside much larger hydrogel microcapsules that cannot be taken up by cells. This hybrid nano-in-micro design provided long-term protection and delivery of the growth factor. When they tested their system in a mouse model of ischemia, they observed successful differentiation of stem cells, growth of blood vessels and the restoration of blood supply, collectively rescuing muscle tissue and saving the limbs of the mice.

The results of their study are featured on the ACS Central Science homepage.

“Ischemic diseases are the leading cause of mortality worldwide,” said He. “Therefore, with further development into the clinic, this novel therapy may be used to address a huge healthcare burden.

The study authors received external funding from the National Institutes of Health and the National Science Foundation.

He has applied similar biomimetic approaches to his work on potential treatments for acute myocardial infarction and female infertility.

ACS Central Science publishes the most compelling, important primary reports on research in chemistry and in allied fields, wherein chemical approaches play a key role. It is also the first fully open access journal published by the American Chemical Society. Popularized almost 40 years ago, the term "central science" is frequently used to describe chemistry's focal role in bridging the physical and life sciences, and the basic sciences with applied disciplines such as medicine and engineering.