Stanford University researchers investigate the role of wireless smart bandaging in skin tissue repair

Stanford University researchers report that they have developed a wireless smart dressing that has shown promise in accelerating tissue repair in chronic wounds by monitoring the healing process and treating the wound simultaneously. In an article published in Nature Biotechnology, the researchers say their device promotes faster wound closure, increases new blood flow to injured tissue, and improves skin recovery by significantly reducing scar formation.

The smart bandage is made up of wireless circuitry that uses impedance/temperature sensors to monitor wound healing progress. If the wound is less healed or if an infection is detected, the sensors inform a central processing unit to apply more electrical stimulation to the wound bed to speed tissue closure and reduce infection. Researchers were able to track real-time sensor data on a smart phone, all without the need for wires.

The electronic layer, including a microcontroller (MCU), radio antenna, memory, electrical stimulator, biosensors and other components, is only 100 microns thick, about the thickness of a single layer of latex paint. The circuit relies on a designed hydrogel that is embedded to both deliver healing electrical stimulation to injured tissue and collect real-time biosensor data.

The hydrogel polymer is designed to adhere securely to the wound surface when needed, but to remove cleanly and gently without damaging the wound when warmed to a few degrees above body temperature (40 °C/104°F).

“By sealing the wound, the smart bandage protects while it heals,” said Yuanwen Jiang, study co-first author and post-doctoral researcher in the lab of Zhenan Bao, KK Lee Professor of Chemical Engineering at the Stanford school. of Engineering. “But it’s not a passive tool. It is an active healing device that could transform the standard of care in the treatment of chronic wounds.

It has been previously reported that electrical stimulation (galvanotaxis) accelerates the migration of keratinocytes to the wound site, limits bacterial infections and prevents the development of biofilms on wound surfaces, proactively promotes tissue growth and helps in tissue repair. Researchers were able to use this technology and integrate it with real-time biosensor data to provide a novel biosensor-informed automated treatment modality.

The smart bandage’s biosensing capabilities monitor biophysical changes in the local environment, providing a real-time, rapid, robust and highly accurate means of measuring wound status, the study authors said.

Anti-inflammatory gene

The researchers took their study a step further, venturing 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 helps eliminate pathogens and repair wounds, and Apoe, which has been shown to increase muscle and soft tissue growth. . Similarly, electrical stimulation increased the amount of white blood cell populations, namely monocytes and macrophages, through the recruitment of greater amounts of anti-inflammatory M2 macrophages, which have been previously reported to be pro-regenerative and play a key role in the formation of the extracellular matrix. necessary during the proliferative phases of wound healing.

The researchers warn that the smart bandage is, for now, a proof of concept, albeit a promising one. However, many challenges remain. These include increasing the size of the device on a human scale, reducing costs and solving long-term data storage issues – all necessary to move to mass production when needed. and opportunity. Likewise, there are potentially new sensors not currently integrated 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, in which the skin can react to the device and create a bad gel-skin combination, or biofouling of the sensors, which can cause irritation. The researchers are moving forward and remain optimistic about the potential of their smart bandage to bring hope to patients with chronic wounds.

Stanford’s co-first authors are: Yuanwen Jiang, a Bao Group postdoctoral fellow; Artem Trotsyuk, former Gurtner Lab graduate student; and Simiao Niu, a former Bao Group postdoctoral researcher.