Scientists have known for some time that electrical stimulation can speed the healing of chronic wounds, such as diabetic skin ulcers. A new thin, flexible, inexpensive bandage delivers this healing current directly to the wound site and is activated simply by adding water.
First of all, how? to do Does electricity promote healing? When a mild electric current is passed through damaged tissue, it increases the rate at which keratinocytes (skin cells) migrate to the wound site, accelerating tissue closure. It also kills bacteria, reducing infection.
A number of wound-damaging dressings have been designed with this in mind, but they are not without their limitations. For example, some contain relatively thick batteries and other electronics, making them both expensive and difficult to wear.
Others forego the battery for a wirelessly delivered power source, but Them requires patients to remain in close proximity to a transducer coil emitting an electromagnetic field. This setup severely limits patient mobility.
That's where the experimental new WPED (Water Powered Non-Electronic Wearing) comes into play.
Developed by a team of American and Korean scientists, the product takes the form of a ready-made adhesive bandage with two electrodes attached to the bottom and a thin, flexible battery attached to the top. When the disposable bandage is applied directly to a chronic wound, the electrodes adapt to the contours of the damaged tissue.
The cell consists of a magnesium anode and a silver chloride cathode separated by a layer of cellulose impregnated with sodium chloride. As long as this cellulose remains dry, the cell remains inactive. However, when the cellulose separator is wetted with a drop of water, ions can pass through it from the anode to the cathode.
As a result, the battery starts to produce a radial electric field of ~1.5 volts that spreads through the electrodes to the underlying tissue. One application of water should be good for up to seven hours of electrical stimulation, after which time the separator will be dry. We were told that wetting it again would be good for about two hours of battery activation, but since WPED is so cheap—about a US dollar a pop—it would be best to apply a new one and throw away the old one.
Importantly, the bandage can be self-applied and activated by patients in their own homes. It then remains securely and unobtrusively in place while they go about their daily activities, conducting its own healing current. In laboratory tests on mice, diabetic skin ulcers treated with WPED healed approximately 30% faster than wounds treated with conventional bandages.
“The next steps for us include additional studies to fine-tune our ability to reduce the fluctuations in the electric field and extend the duration of the field,” says Amay Bandodkar, an assistant professor at North Carolina State University and co-corresponding author of the study. “We are also moving forward with additional tests that will bring us closer to clinical trials and—ultimately—practical use that could help humans.”
A paper on the research (which also involved scientists from Columbia University, Beth Israel Deaconess Medical Center, Georgia Tech, Korea University and the Korea Institute of Science and Technology) was recently published in the journal Science Advances.
Source: North Carolina State University