It is estimated that 15 percent of people with diabetes will, at some point in their lives, develop a painful and hard-to-treat foot ulcer. Of that 15 percent, Twenty-four percent will require a lower-leg amputation.
In some cases, what was first thought to be a harmless sore could even lead to death.
That’s why there is hope in a new treatment developed by a Northwestern Engineering team called a “regenerative bandage.” Made with advanced materials, it is designed to heal diabetic wounds four times faster than a standard bandage.
“By mimicking the repair process that happens in a healthy body, we have demonstrated a promising new way to treat diabetic wounds.”
“Foot ulcers cause many serious problems for diabetic patients,” said Guillermo Ameer, professor of biomedical engineering in the McCormick School of Engineering and surgery in the Feinberg School of Medicine. “Some sores don’t heal fast enough and are prone t oinfection. We thought that we could use some of our work in biomaterials for medical applications and controlled drug release to help heal those wounds.”
According to a release from Northwestern:
Some promising treatments for these chronic wounds exist, but they are costly and can come with significant side effects. One gel, for example, contains a growth factor that has been reported to increase cancer risk with overuse.
“It should not be acceptable for patients who are trying to heal an open sore to have to deal with an increased risk of cancer due to treating the wound,” Ameer said.
Dr. Guillermo Ameer
Ameer’s laboratory previously created a thermo-responsive material — with intrinsic antioxidant properties to counter inflammation — that is able to deliver therapeutic cells and proteins.
His team used this material to slowly release into the wound a protein that hastens the body’s ability to repair itself by recruiting stem cells to the wound and creating new blood vessels to increase blood circulation.
“We incorporated a protein that our body naturally uses to attract repair cells to an injury site,” Ameer said. “When the protein is secreted, progenitor cells or stem cells come to the wound and make blood vessels, which is part of the repair process.”
The thermo-responsive material is applied to the wound bed as a liquid and solidifies into a gel when exposed to body temperature. When the same amount of the protein was directly applied all at once, no benefit was observed. This demonstrates the importance of slow release from the thermo-responsive material. Ameer believes that the inherent antioxidant properties within the material also reduce oxidative stress to help the wound heal.
“The ability of the material to reversibly go from liquid to solid with temperature changes protects the wound,” Ameer said. “Patients have to change the wound dressing often, which can rip off healing tissue and re-injure the site. Our material conforms to the shape and dimensions of the wound and can be rinsed off with cooled saline, if needed. This material characteristic can protect the regenerating tissue during dressing changes.”
In collaboration with Zhang, Ameer imaged diabetic wounds to discover that they were much healthier after application of the regenerative bandage. The blood flow to the wound was significantly higher than in those without Ameer’s bandage.
“The repair process is impaired in people with diabetes,” Ameer said. “By mimicking the repair process that happens in a healthy body, we have demonstrated a promising new way to treat diabetic wounds.”