A wireless smart dressing provides new insights into chronic wound healing

A wireless smart dressing provides new insights into chronic wound healing

Drawing of a wireless smartband on a human arm. Credit: Jian-Cheng Lai, Bao Research Group @ Stanford University

Some wounds just don’t heal. Infections, diseases such as diabetes and a suppressed immune system often pile up for slow healing. Chronic ulcers can last for months and lead to anxiety and depression. In the worst cases, they are life-threatening. The cost of treatment has risen to $25 billion each year.

Until now, solutions for treating chronic wounds have been few and far between, but researchers at Stanford University now say they have developed a wireless smart bandage that has shown promise in speeding up tissue repair by monitoring the wound healing process and treating wounds at the same time.

The researchers say in a paper published on November 24 Nature Biotechnology that their device promotes faster wound closure, increases new blood flow to injured tissue, and enhances skin recovery by significantly reducing scarring.

The smart bandage is composed of wireless circuits that use resistance/temperature sensors to monitor the progress of wound healing. If the wound is less healed or an infection is detected, the sensors inform the central processing unit to apply more electrical stimulation across the wound bed to accelerate tissue closure and reduce infection. Researchers were able to monitor sensor data in real time on a smartphone, all without the need for wires.

An engineering marvel

The electronic layer, including a microcontroller unit (MCU), radio antenna, memory, electrical stimulation, biosensors and other components, is only 100 microns thick – about the thickness of one layer of latex paint.

All of this circuitry rides atop a cleverly designed hydrogel—a rubbery, skin-like polymer—that’s integrated to both deliver healing electrical stimulation to injured tissue and collect real-time biosensor data.

The polymer in the hydrogel is carefully designed to adhere securely to the wound surface when needed, yet pull away cleanly and gently without damaging the wound when heated to just a few degrees above body temperature (40°C/104°F).

“When sealing the wound, the smart bandage protects as it heals,” says Yuanwen Jiang, co-first author of the study and a postdoctoral fellow in the lab of Zhenan Bao, the KK Lee Professor of Chemical Engineering at Stanford School of Medicine. engineering. “But it’s not a passive device. It’s an active therapeutic device that could transform standard of care in the management of chronic wounds.”

A wireless smart dressing provides new insights into chronic wound healing

Photographs of the smart bandage showing the microcontroller unit (MCU), crystal oscillator, high-pass filter (HPF), excitation and sensing electrodes, flexibility of the printed circuit, adhesion of the hydrogel interface to the skin, and thin board layout. . Credit: Jian-Cheng Lai, Bao Research Group @ Stanford University

Electrical stimulation, also known as galvanotaxis, has previously been reported to accelerate the migration of keratinocytes to the wound site, limit bacterial infection and prevent biofilm formation on wound surfaces, promote tissue growth and aid tissue repair. The researchers were able to take this well-researched technology and integrate it with real-time biosensor data to provide a new biosensor-informed automated therapy approach.

The smart dressing’s biosensing capabilities monitor physiological changes in the local environment and provide a real-time, fast, robust, and highly accurate way to measure the condition of the wound. Technically, the smart bandage senses conductivity and temperature changes in the skin as the wound heals – electrical resistance increases as wounds heal and local temperature decreases as inflammation decreases.

“With stimulation and sensing in one device, the smart bandage accelerates healing, but it also monitors the healing process,” says Artem Trotsyuk, also co-author of the study who completed his graduate work in Geoffrey’s lab. Gurtner, MD, formerly Johnson & Johnson Distinguished Professor of Surgery (Emeritus) at Stanford School of Medicine, and now Chair of the Department of Surgery and Professor of Biomedical Engineering at the University of Arizona in Tucson.

“We believe it represents a new method that will enable new biological discovery and exploration of previously difficult-to-test hypotheses about the human healing process.”

Welcome results, new ways

The researchers took the research a step further and ventured to understand why and how electrical stimulation heals the wound faster. They now believe that electrical stimulation promotes the activation of pro-regenerative genes such as Selenop, an anti-inflammatory gene that has been shown to aid in pathogen clearance and wound repair, and Apoe, which has been shown to increase muscle and soft tissue growth. .

Likewise, electrical stimulation increased the amount of white blood cells, i.e. monocytes and macrophages, by recruiting more M2 pro-inflammatory macrophages, previously reported to be pro-regenerative and play a key role in extracellular matrix formation. which is essential during the proliferative stages of wound healing.

The researchers caution that the smart bandage is still a proof-of-concept, though promising. However, many challenges remain. This includes increasing the size of the device to human scale, reducing costs and solving long-term data storage problems – all necessary to scale up to mass production if the need and opportunity arise.

Likewise, there are potentially new non-integrated sensors that could be added, such as those that measure metabolites, biomarkers, and pH. And there are some potential barriers to clinical use, such as hydrogel rejection, where the skin can react with the device and create a bad gel-to-skin combination, or sensor biowetting, which can cause irritation.

Despite these obstacles, the researchers are moving forward and remain optimistic about the potential of their smart bandage to offer hope to patients suffering from chronic wounds.

More information:
Geoffrey Gurtner et al., A Wireless Closed-Loop Smart Bandage with Embedded Sensors and Stimulators for Advanced Wound Management and Rapid Healing, Nature Biotechnology (2022). DOI: 10.1038/s41587-022-01528-3

Provided by Stanford University

Quotation: Wireless smart bandage offers new insights into healing chronic wounds (2022, November 24) Retrieved November 25, 2022 from https://medicalxpress.com/news/2022-11-wireless-smart-bandage-insights-chronic.html

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