Dr. Lewis Reis (left) and Professor Milica Radisic used their unique peptide-hydrogel biomaterial to heal chronic wounds faster than commercially available products. (Photo by Marit Mitchell)
Researchers at the University of Toronto have demonstrated that a peptide-hydrogel biomaterial prompts skin cells to “crawl” toward one another, closing chronic, non-healing wounds often associated with diabetes, such as bed sores and foot ulcers.
The team, in their study published in the journal Proceedings of the National Academy of Sciences (Sept. 19, 2016), tested their biomaterial on healthy keratinocytes, as well as on keratinocytes derived from elderly diabetic patients. They saw non-healing wounds close 200% faster than with no treatment, and 60% faster than treatment with a leading commercial collagen-based product.
“We were happy when we saw the cells crawl together much faster with our biomaterial, but if it didn’t work with diabetic cells, that would have been the end of the story,” said Milica Radisic, PhD, a professor in Chemical Engineering & Applied Chemistry at the university, in a press release. “But even the diabetic cells travelled much faster—that’s huge.”
Until now, most treatments for chronic wounds involved applying topical ointments that promote the growth of blood vessels to the area. But in diabetic patients, blood vessel growth is inhibited, making those treatments ineffective. Dr. Radisic and her team have been working with their special peptide—called QHREDGS, or Q-peptide—for almost 10 years. They knew it promoted survival of many different cell types, including stem cells, heart cells, and fibroblasts, but had never applied it to wound healing.
“We thought that if we were able to use our peptide to both promote survival and give these skin cells a substrate so they could crawl together, they would be able to close the wound more quickly,” said Radisic. “That was the underlying hypothesis.”
From left: Skin cells without the research team’s peptide-hydrogel treatment, cells treated with a low dose, and cells treated with a high dose. Skin cells migrate together fastest with a high dose of the peptide-hydrogel material. (Courtesy: Radisic Lab)
Dr. Radisic and PhD students Yun Xiao and Lewis Reis compared the Q-peptide-hydrogel mix to the commercially available collagen dressing, to hydrogels without the peptide, and to no treatment. They found that a single dose of their peptide-hydrogel biomaterial closed the wounds in less than two weeks.
“Currently, there are therapies for diabetic foot ulcers, but they can be improved,” said Xiao, the paper’s lead author. “Diabetic wound healing is a complicated condition, because many aspects of the normal wound healing process are disrupted—I know people with diabetic foot ulcers, and the possibility to improve their lives drove me throughout this work.”
The multidisciplinary team worked with Covalon Technologies Ltd., a company involved in the research and development and commercialization of novel healthcare technologies, on this project. Covalon’s chief scientific officer, Dr. Val DiTizio, has been leading the partnership with Radisic’s group for about three years, and contributed its collagen-based wound-healing dressing, C01Active, as one of the controls.
“We believe strongly in keeping abreast of new technologies being developed in academia,” said Dr. DiTizio, who is also working with Dr. Radisic on a bone-regeneration project. “Collaborations such as this one inform our future research directions and help make our products better.”
This finding could have significant implications for many types of wound treatments, from recovery after a heart attack to healing post-surgery. Accelerated healing times also introduces the added benefit of reducing the opportunity for infection, said Reis.