It was June 2007 when diabetic Tim Johnson developed a stubborn and debilitating foot ulcer "It started out with a blister," Johnson explains. "It put me out of work. I have yet to work since the end of June."
Because Johnson, like many diabetics, suffers from a loss of feeling in his feet, the ulcer is difficult to feel and heal.
"If somebody doesn't have diabetes and gets a foot ulcer, it's so painful, they would never walk on that wound," said Dr. Bill Marston, Medical Director of UNC's Wound Healing and Limb Salvage Center. "Whereas, if a person with diabetes has neuropathy, they can't feel the foot. So, despite having a wound on the foot, they'll continue to walk on it and make it worse. That can infect the bone resulting in tissue loss.
Dr. Marston is working to get Johnson's ulcer to heal. But, if it doesn't, and becomes severely infected, Johnson could be susceptible to an increased risk for a foot amputation. "Most of the amputations will be with people with diabetes, not all of them, but the majority and almost all of them start with the foot ulcer," said Marston.
In North Carolina, there are about 3 thousand amputations performed each year.
"It's about 80 thousand nationwide, "said Marston. "Since we have a high instance of diabetes in NC, we probably have more than our share.
But, Dr. Marston is helping to test out a treatment that could help patients like Johnson. It's called Excellarate. It's a DNA-based topical gel that stimulates wound healing. "This is a gel that actually has a piece of DNA encoded in it," said Marston. "That is transmitted to the cells to turn the cells on and get them to produce a growth factor that will stimulate healing."
Researchers at UNC Hospitals are testing out the gel along with about 25 other medical centers across the country. It's not yet FDA approved because this is a clinical trial. But, doctors say this type of DNA technology looks very promising.
"We hope that this will make a big difference with patients," said Marston. And for his foots sake, patient Tim Johnson is hoping the same thing.