Posted: Aug 2, 2012 10:33 PM
Aug. 2, 2012 -- An experimental spray-on skin product may help people with chronic leg wounds heal faster and more effectively than available treatments, a new study suggests.
The spray-on skin is made up of skin cells and suspended in a mixture of different types of proteins. The participants in this study all had venous leg ulcers, which are shallow wounds that occur in people who have a circulation problem in their veins. These wounds tend to develop on the inside of the lower leg. Most at risk for venous ulcers are inactive and obese people, as well as people with varicose veins.
People in the study who used the new treatment experienced a greater reduction in wound size than those who didn't use it.
The findings appear in the Lancet.
Healthpoint Biotherapeutics of Fort Worth, Texas, is developing the new product and sponsored the study.
As it stands, most venous leg ulcers are treated with compression bandages. Some doctors also use skin grafts in which skin is taken from another area of the body and used to resurface the wound. Skin grafts involve surgery, and people can develop a wound at the skin donation site, too.
"If you don't get these to heal, they become chronic, and the older the wounds are, the harder they become to heal with anything," says researcher Herbert B. Slade, MD. He is a pediatrician at the University of North Texas Health Science Center in Fort Worth and is also the chief medical officer at Healthpoint Biotherapeutics. "Compression bandages work for 30% to 70% of people, but are not 100% effective."
That is where the spray-on treatment may come in.
In the 12-week study of 205 people, those who received the spray-on treatment and compression bandaging had a greater reduction in wound size than those who used compression bandaging without the test treatment.
Researchers tested two strengths of the new therapy, along with compression bandages. The biggest improvements were seen in the lower-strength dose given every two weeks; there was a 16% greater reduction on average of the wound area, compared to a group that was given a spray that didn't contain the new therapy, after 12 weeks.
Side effects were similar in the different groups. The spray-on treatment sped wound closure by an average of 21 days compared to the comparison group.
Slade and colleagues are now assessing its safety and conducting studies to determine exactly how it works. "The FDA wants us to better define what it is that is happening when the cells get on the surface of the wound," he says. "We know it works, we just need to know more about how."
According to Slade, the sprayed-on cells help the tissue learn how to regenerate itself. If the findings are confirmed by follow-up studies, "it's going to be an off-the-shelf product." No information is available about cost at this time.
The need for new products to treat these wounds is tremendous, Matthias Augustin, MD, says in an email. "A significant number of patients fail to respond to any therapy."
Augustin, the director of the Institute for Health Services Research in Dermatology and Nursing at the University Clinics of Hamburg in Hamburg, Germany, wrote an editorial accompanying the new study.
"New treatments with improved healing and healing rates are needed to reduce the burden of ulcers for patients, [and] while more research is needed I believe that this product could ultimately make a significant difference for these patients."
John Lantis, MD, is one of the investigators on the study. "This could be used in any place that artificial skin is needed, such as diabetic foot ulcers," says Lantis, who is the chief of the vascular surgery division at St. Luke's-Roosevelt Hospital in New York City.
It will not be a stand-alone treatment. "If you have a diabetic foot ulcer, you will still have to wear special diabetic shoes," he says. "It's not like you can just spray it on and go about your business. It will always be used in conjunction with current standard of care."
It seems to perform better than any other artificial skin products out there or in the pipeline, Lantis says.
Maja Zaric, MD, says there may well be a role for this product. She is an interventional cardiologist at Lenox Hill Hospital in New York City. "The spray can be applied in various doses and it is very user-friendly, unlike a skin graft."
Still, not every person with a venous leg ulcer would benefit from the new spray-on skin. "Those who would benefit the most have extremely large ulcers and decreased blood flow," she says. Before treating these wounds, Zaric always does a vein-mapping study to see which veins are causing the problem.
Neil Sadick, MD, is a New York City dermatologist and clinical professor of dermatology at Weill Cornell Medical College. "This treatment provides a cocktail of cells and growth factors," he says. "These ingredients can stimulate new collagen, which would improve wound healing and also help recover the skin." Collagen is the main structural protein in skin.
"It could well be helpful in wound healing and it could be helpful in any area where we need to replace the skin surface," Sadick says.