Some wounds just don’t heal. Infections, diseases such as diabetes, and suppressed immune systems often accumulate to delay healing. Chronic wounds can last for months and cause anxiety and depression. At worst, they are life-threatening.
Until now, solutions for the treatment of chronic wounds have been scarce, but researchers at Stanford University (USA) have developed a wireless smart bandage that has shown promise in accelerating tissue repair by monitoring the wound healing process and its simultaneous treatment.
The researchers state in an article published in “Nature Biotechnology” that their device promotes faster wound closure, increases blood flow to injured tissue and improves skin recovery by significantly reducing scar formation.
The smart bandage consists of wireless circuits using sensors of impedance/temperature to monitor the progression of wound healing. If the wound is less healed or infection is detected, sensors inform a central processing unit to apply more electrical stimulation to the wound bed to speed tissue closure and reduce infection.
The researchers were able to follow the data from the sensors in real time on a smartphone, all without the need for cables.
“By sealing the wound, the smart bandage protects while it heals,” says Yuanwen Jiang, co-first author of the study. “But 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, is known to accelerate the migration of keratinocytes to the wound site, limit bacterial infections, and prevent the development of biofilms on wound surfaces, to proactively promote tissue growth and help repair it. The researchers were able to use this technology and integrate it with real-time biosensor data to offer a novel automated treatment modality that relies on biosensors.
The smart dressing’s biosensing capability monitors biophysical changes in the local environment, providing a fast, robust and extremely accurate way to measure wound status in real time. From a technical point of view, the smart bandage detects changes in conductivity and temperature on the skin as the wound heals: electrical impedance increases as wounds heal and local temperature decreases as inflammation subsides.
This modality will enable new biological discoveries and the exploration of hypotheses about the human healing process.
“With pacing and sensing in a single device, the smart bandage accelerates healing, but also tracks wound improvement,” says Artem Trotsyuk, also the study’s first author. “We believe it represents a new modality that will enable new biological discoveries and exploration of hitherto difficult-to-test hypotheses about the human healing process.”
The researchers took their study a step further, venturing to understand why and how electrical stimulation heals wounds more quickly. Now they believe that electrical stimulation promotes the activation of pro-regenerative genes such as Selenop, an anti-inflammatory gene that has been found to aid pathogen clearance and wound repair; and Apoe, which has been shown to increase the growth of muscle and soft tissue.
In addition, electrical stimulation increased the number of white blood cell populations, specifically monocytes and macrophages, by recruiting greater numbers of anti-inflammatory M2 macrophages, which have previously been reported to be pro-regenerative and play a key role in cell function. formation of the extracellular matrix that is required during the proliferative phases of wound healing.
Now, the researchers caution that the smart bandage is still a proof of concept, albeit promising, although many challenges remain. Among them, increasing the size of the device to human scale, reducing the cost and solving the problems of long-term data storage, all necessary to scale up to mass production if the need and opportunity arise.