A foot ulcer is typically a painful inconvenience to most people, but to a person with diabetes it could mean an infection, or worse, an amputation. But a research team has developed a drug delivered through a skin patch that not only helps foot wounds heal better, but also prevents those wounds from recurring, according to study results they presented this week at the American College of Surgeons Annual Clinical Congress.
Amputations are one of the most serious complications of diabetes. About 29.1 million Americans are living with diabetes. Among adults who have lower-limb amputations unrelated to trauma, about 60 percent have been diagnosed with diabetes, according to the American Diabetes Association.
Foot ulcers are a major reason why people with diabetes end up needing foot amputations, however, even after that operation, many diabetes patients fare worse. It's not just having your leg surgically removed, but an amputation sends these patients into a downward spiral where they are not active. Then, all the other health issues that accompany inactivity come into play. A diabetic patient who undergoes an amputation has a 50 percent five-year mortality, which is worse than breast cancer or Hodgkin's disease.
Foot ulcers are particularly dangerous for people with diabetes because the impaired blood flow prevents the wound from healing properly. Blockages of the big blood vessels can be cleared out with stents or bypasses, but that treatment only solves half the problem. In addition to blocked blood vessels, the blood sugar toxicity in people with diabetes impairs a protein, called hypoxia inducible factor-1 alpha (HIF-1α). This protein turns on the genes that help form new networks of small blood vessels needed to heal damaged tissue.
With that mechanism in mind, the researchers developed a drug that increases the protein HIF-1α in diabetes patients. The drug's main ingredient is another medication that has been available for more than 60 years, called deferoxamine. But the drug's molecules are too large to penetrate the skin adequately, so they also needed to develop a transdermal patch to serve as the drug's delivery tool.
The research team tested both methods using a human skin apparatus. Their results showed that the patch had several advantages over a topical solution: The wound healed 14 days faster, and it boosted the quality of the wound healing by improving the damaged skin's collagen levels. These advantages also help to solve another problem. Because the patch helps the skin heal better, there's a chance that this could prevent repeat ulcers, and maybe even the initial ulcers too.
The next step to bring the drug to market is a clinical trial testing the drug with diabetes patients who are at risk for foot ulcers.