Encapsulated Stem Cells Could Accelerate Wound Healing

Encapsulated Stem Cells Could Accelerate Wound Healing

Mesenchymal stem cells captured in microcapsules. Each microcapsule is roughly 40 micrometers across.

Photo: Courtesy Rebecca Harman

A team of Cornell University scientists has shown that equine stem cells confined inside tiny capsules secrete substances that help heal simulated wounds in cell cultures, opening up new ways of delivering these substances to the locations in the body where they can hasten healing. The capsules need to be tested to see if they help healing in live horses, but they could eventually lead to “living bandage” technologies, wound dressings embedded with capsules of stem cells to help the underlying wound regenerate.

“The encapsulation seems to increase the stem cells’ regenerative potential,” said Gerlinde Van de Walle, DVM, PhD, an assistant professor of viral pathogenesis at the Cornell College of Veterinary Medicine’s Baker Institute for Animal Health, in Ithaca, New York, adding that the reasons why are not yet known. “It's possible that putting them in capsules changes the interactions between stem cells or changes the microenvironment.”

To her knowledge, Van de Walle said, this is the first time encapsulated stem cells have been used for treating wounds. Her team used horse stem cells and cell cultures because of the particular problem posed by wound healing in veterinary medicine.

Adult stem cells help wounds heal, even when trapped in capsules

Mesenchymal stem cells are adult stem cells that can be isolated from any of a number of different parts of the body, and it’s long been known that they secrete substances that aid in tissue healing. Problems arise when trying to use these stem cells in real patients, Van de Walle said, because they often won’t stay put in the healing area and can occasionally form tumors or develop into unwanted cell types.

She and her team began exploring the possibilities of encapsulating these cells as a way of avoiding these pitfalls. The capsules help the cells stay in place while they secrete substances into the wound, and can be removed easily if the stem cells would develop in an adverse way. The collaborated with Mingling Ma, PhD, of Cornell’s Department of Biological and Environmental Engineering and his laboratory, to create the coreshell hydrogel microcapsules around the stem cells.

Van de Walle says she was excited to see that the capsules did not abolish the stem cell properties but instead appeared to enhance the beneficial effects the stem cell secreted products have on tissue cultures. This suggests that encapsulating the stem cells for wound healing can not only avoid certain problems, it can actually boost the effectiveness of treatment.

A growing area of equine medicine, but do the techniques work?

With their mesenchymal stem cell work, Van de Walle and her colleagues are trying to understand the basic science behind this booming area in equine medicine.

“Currently many equine veterinarians are using stem cells for therapy, but the mechanisms in which they work—and their potential—haven’t been fully explored,” said co-author Rebecca Harman, BS, a graduate student in Van de Walle’s laboratory. Stem cells can be used in horses without much regulatory oversight, but studies to back up many of these uses are lacking. Van de Walle and Harman hope to shed some light on an area that is poorly understood.

More studies ahead

This new work shows microencapsulated stem cells have a great deal of promise, said Harman, but there’s a lot to do before they could be embedded in bandages and used in veterinary clinics. Since skin is a complex organ, the approach needs to be studied in a variety of cell culture systems before moving forward with tests on humans or horses.

“Studying how this works in horses is the ultimate goal, but there’s still work to be done in the laboratory first. We're expanding our cell culture experiments to include other cell types present in skin,” Harman said.

The study, “Microencapsulated equine mesenchymal stromal cells promote cutaneous wound healing in vitro,” was published in Stem Cell Research & Therapy

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