According to the paper “Preventing foot ulcers in patients with diabetes” published in 2005 by Singh, Nalini, David G. Armstrong, and Benjamin A. Lipsky, approximately a quarter of diabetic patients suffer from painful and potentially dangerous foot ulcers which are slow to heal, due to impaired blood vessels and poor oxygenation to the wound.
Thanks to a team of researchers at the McKelvey School of Engineering at Washington University in St. Louis, the wounds could heal better and faster. Jianjun Guan, a professor of mechanical engineering & materials science and his team, have developed a hydrogel that provides oxygen to a wound, which decreases inflammation, helps remodel tissue and accelerates healing.
“The oxygen has two roles: one, to improve skin cell survival under the low-oxygen condition of the diabetic wound; and two, oxygen can stimulate the skin cells to produce growth factors necessary for wound repair,” Guan said.
As we know, the body needs constant oxygen to survive and thrive, but especially when a tissue is injured. Some existing treatments for people with diabetes include dozens of sessions in a hyperbaric oxygen chamber, but its effectiveness is inconsistent and risks oxygen toxicity.
Guan’s hydrogel works using microspheres that gradually release oxygen to interact with the cells through an enzyme on their surface that transforms what is inside of the microsphere into oxygen. The oxygen is provided to the wound during an approximate two-week period, and inflammation decreases, it prompts healing.
According to the study, done in mice, “wounds treated with the hydrogel containing the oxygen-releasing microspheres had a higher rate of closure than wounds treated with only the gel or those with no treatment. Within 16 days, the wounds treated with the hydrogel had reduced to 10.7%. Those treated with the gel only were reduced to 30.4%, and those with no treatment had reduced to 52.2%.
In addition, the wounds treated with the hydrogel containing the oxygen-releasing microspheres had the thickest epidermis on day 8, but the thinnest by day 16, indicating the wound was healing and inflammation was reduced.”
“The gel is a liquid before we put it into the skin tissue, so it is easy to mix in the microspheres,” he said. “Once we put the mixture of the gel and the microspheres into the wound, it becomes a solid because it is temperature-sensitive — at lower temperatures it is a liquid, and at body temperature it’s a solid.”
A risk is delivering too much oxygen, which creates reactive oxygen species (ROS), that can damage or kill cells at elevated levels. However, Guan’s hydrogel scavenges for ROS content and destroys it, eliminating any risk.
Guan’s team aims to use the hydrogel in a large animal model with the hope of future human clinical trials.
“This represents a new therapeutic approach to accelerating healing of chronic diabetic wounds without drugs,” Guan said. ‘It also has the potential to treat other diseases in which oxygen is low, such as peripheral artery disease and coronary heart disease.”