Researchers at Columbia University Medical Center (CUMC) and the University of North Carolina have developed a medicated skin patch capable of transforming white fat into energy burning brown fat. The study, published in ACS Nano, aimed for the patch to treat metabolic disorders like obesity and diabetes.

With obesity and diabetes on the rise, researchers turn to internal, non-invasive solutions to help patients lose weight. The patch, lined with drug filled nanoparticles that are loaded into microscopic needles, can be placed on the skin of fatty areas to gradually release the drugs. Over time, these patches change white fat into brown fat, burning off the excess weight in the area.

"There are several clinically available drugs that promote browning, but all must be given as pills or injections," said study co-leader Li Qiang, PhD, assistant professor of pathology and cell biology at CUMC. "This exposes the whole body to the drugs, which can lead to side effects such as stomach upset, weight gain and bone fractures. Our skin patch appears to alleviate these complications by delivering most drugs directly to fat tissue."

In the study, researchers applied the patch to obese mice to test its safety and effectiveness. A group of mice were given placebo patches while other mice received the medicated patch, each mouse had the patches placed on the lower abdomen and had them changed every three days for four weeks. Results showed the medicated patch mice were able to reduce fat by 20 percent as well as having significantly lower fasting blood glucose levels.

"The nanoparticles were designed to effectively hold the drug and then gradually collapse, releasing it into nearby tissue in a sustained way instead of spreading the drug throughout the body quickly," said patch designer and study co-leader Zhen Gu, PhD, associate professor of joint biomedical engineering at the University of North Carolina at Chapel Hill and North Carolina State University.