Electronic bandage speeds healing and dissolves in body

The small, flexible bandage delivers electrotherapy directly to the wound site. In an animal study, researchers reported that when worn for just 30 minutes per day, the bandage healed diabetic ulcers 30 per cent faster than in mice without the bandage.

The team at Northwestern University believes it could provide a powerful tool for patients with diabetes, whose ulcers can lead to complications including amputated limbs or even death. Because diabetes can cause nerve damage that leads to numbness, people with diabetes might experience a simple blister or small scratch that goes unnoticed and untreated. As high glucose levels also thicken capillary walls, blood circulation slows, making it more difficult for these wounds to heal.

The team’s work was published in the journal Science Advances. Researchers believe it is the first bioresorbable bandage capable of delivering electrotherapy and the first example of a smart regenerative system.

“Our new bandage is cost-effective, easy to apply, adaptable, comfortable and efficient at closing wounds to prevent infections and further complications,” said Northwestern’s Guillermo A. Ameer, Daniel Hale Williams Professor of Biomedical Engineering, who co-led the study.

Northwestern’s John A. Rogers, who co-led the study, explained that the active components that interface with the wound bed are entirely resorbable, disappearing naturally after the healing process is complete and avoiding any tissue damage that could otherwise be caused by physical extraction.

According to Ameer, injuries can disrupt the body’s normal electrical signals. By applying electrical stimulation, it restores the body’s normal signals, attracting new cells to migrate to the wound bed.

“Our body relies on electrical signals to function,” Ameer said. “We tried to restore or promote a more normal electrical environment across the wound. We observed that cells rapidly migrated into the wound and regenerated skin tissue in the area. The new skin tissue included new blood vessels, and inflammation was subdued.”

Historically, clinicians have used electrotherapy for healing, but most of that equipment includes wired, bulky apparatuses that can only be used under supervision in a hospital setting.

One side of the team’s smart regenerative system contains two electrodes: a tiny flower-shaped electrode that sits right on top of the wound bed and a ring-shaped electrode that sits on healthy tissue to surround the entire wound.

The other side of the device contains an energy-harvesting coil to power the system and a near-field communication (NFC) system to wirelessly transport data in real time.

The team also included sensors that can assess how well the wound is healing. By measuring the resistance of the electrical current across the wound, physicians can monitor progress. A gradual decrease of current measurements relates directly to the healing process so if the current remains high, physicians know something is wrong.

By building in these capabilities, the device can be operated remotely without wires. From afar, a physician can decide when to apply the electrical stimulation and can monitor the wound’s healing progress.

“As a wound tries to heal, it produces a moist environment,” Ameer said. “Then, as it heals, it should dry up. Moisture alters the current, so we are able to detect that by tracking electrical resistance in the wound.

“Then, we can collect that information and transmit it wirelessly. With wound care management, we ideally want the wound to close within a month. If it takes longer, that delay can raise concerns.”

The team made the electrodes from a metal called molybdenum, which is widely used in electronic and semiconductor applications. They discovered that when molybdenum is thin enough, it can biodegrade without interfering with the healing process.

“We are the first to show that molybdenum can be used as a biodegradable electrode for wound healing,” Ameer said. “After about six months, most of it was gone. And we found there’s very little accumulation in the organs. Nothing out of the ordinary. But the amount of metal we use to make these electrodes is so minimal, we don’t expect it to cause any major issues.”

The team next plans to test the bandage for diabetic ulcers in a larger animal model, then on humans. Because it leverages the body’s own healing power without releasing drugs or biologics, it faces fewer regulatory hurdles and could therefore be on the market sooner, they confirmed.