Electrical stimulation bandage ‘could offer hope for people with chronic wounds’

The interior of the ‘smart’ bandage, which could be used to treat chronic wounds (Credit: Jian-Cheng Lai, Bao Research Group @ Stanford University)

A wireless ‘smart’ bandage has shown promise for speeding up tissue repair by simultaneously monitoring and treating wounds.

Aimed at addressing a shortage of treatments for chronic wounds, the bandage was developed by researchers at Stanford University in California.

Infections, diseases such as diabetes, and suppressed immune systems can often slow down the healing process. Chronic wounds can last months, leading to anxiety and depression, and becoming potentially life-threatening in the worst cases. They cost $25 billion to treat each year.

The new device promotes faster closure of wounds, increases blood flow to injured tissue, and enhances skin recovery by significantly reducing scar formation, the Stanford team said.

It achieves that with wireless circuitry that uses impedance/temperature sensors to monitor the progression of wound healing. If the wound is healing slowly or an infection is detected, the sensors inform a central processing unit to apply electrical stimulation across the wound bed to accelerate tissue closure and reduce infection. The researchers were able to wirelessly track the sensor data in real time on a smart phone.

The electronic layer, including a microcontroller unit (MCU), radio antenna, memory, electrical stimulator, biosensors and other components, is just 100 microns thick, similar to a single coat of latex paint.

The circuitry sits on top of a hydrogel – a rubbery, skin-like polymer – which is integrated to both deliver electrical stimulation and collect biosensor data. The polymer in the hydrogel is carefully designed to adhere securely to the wound surface when needed, but to pull away cleanly and gently when warmed to just a few degrees above body temperature (40°C).

“In sealing the wound, the smart bandage protects as it heals,” they said Yuanwen Jiangco-first author of the study and post-doctoral scholar in the lab of Zhenan Bao at the Stanford School of Engineering. “It is not a passive tool. It is an active healing device that could transform the standard of care in the treatment of chronic wounds.”

Electrical stimulation, also known as galvanotaxis, has been previously reported to accelerate the migration of keratinocytes to wounds, limiting bacterial infections and preventing the development of biofilms on wound surfaces to proactively promote tissue growth and help with tissue repair.

The smart bandage is still a proof of concept, the researchers said – albeit a promising one. Challenges include increasing the size of the device to human scale, reducing costs, and solving long-term data storage issues, all necessary to scale up to mass production should the need and opportunity arise. Other sensors could also be added to measure metabolites, biomarkers, and pH level. Potential roadblocks to clinical use could include hydrogel rejection, in which the skin may react to the device and create a bad gel-to-skin connection, or biofouling of the sensors, which can cause irritation.

Despite the hurdles, the researchers said they remain optimistic about the potential of their smart bandage to provide hope for patients suffering from chronic wounds.

The research was published in Nature Biotechnology.

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