Hope for people with healing problems: Researchers have developed a prototype wound dressing that can wirelessly record the condition of the area and promote the healing process through stimulation. A "gentle" adhesive hydrogel connects the tissue surface to the system's electronics, which include sensors, a communication antenna and an electrical stimulation unit. The scientists report that the concept has already shown promising results in experiments on mice.
The body can usually repair damage without any problems - but unfortunately this is not the case for many people: infections, diseases such as diabetes and a weakened immune system can lead to wounds healing poorly. The so-called "open leg" is one of these chronic cases. They can cause enormous suffering and also have life-threatening consequences. The problem is therefore of great medical importance and also places a burden on the healthcare system due to the cost of treatment.
A number of different procedures are already being used to improve wound healing. However, the successes still leave a lot to be desired - the further development of treatment methods is therefore required. A research team from Stanford University relied on technology. They are advancing previous approaches for wearable devices designed to enable monitoring and active intervention to promote healing of chronic wounds. They are now presenting their electronic concept, which they believe could develop into a practicable system.
A hydrogel and sleek electronics
The component that makes contact with the wound surface is what is known as a hydrogel – a flexible, skin-like polymer substance. The material is designed to adhere securely to the wound surface, yet release cleanly and gently when needed by heating to just a few degrees above body temperature, without damaging the wound. The hydrogel also has conductive properties that allow it to interface with the overlying electronic component of the system. This includes a microcontroller unit, sensors, an electrical stimulator and an antenna for communication with a mobile phone. The scientists have succeeded in making this electronic ensemble extremely slim: it forms a layer that is only 0.1 millimeters thick.
As the team explains, the included sensors monitor biophysical changes in the wound area, providing a way to measure the condition in real time. Specifically, they record conductivity and temperature changes in the skin. If the so-called electrical impedance increases, this is a sign of healing processes and if the local temperature drops, the inflammation is showing signs of abating. In the event of contrary developments, the system can then intervene. If the wound heals poorly or an infection is detected, the central processing unit is activated, which then activates the electrical stimulation unit. As the researchers explain, it is known that light voltage pulses have a beneficial effect on healing processes: They can accelerate tissue closure and suppress infection processes.
Promising test results
That's the theory. The researchers were then able to prove that the system can deliver what it promises through tests on mice. The wound care system therefore successfully delivered monitoring data and initiated the electrical stimulations depending on the values. This also proved to be successful: the system was able to promote wound closure in the mouse model, increase blood circulation in the tissue and reduce scarring. "In the trials, the wounds in the treatment group healed 25 percent faster and with 50 percent improved skin regeneration compared to the control group," the researchers write. Examinations of the tissue also provided information on the responsible processes: "We observed an activation of pro-regenerative genes in monocyte and macrophage cell populations, which could improve tissue regeneration, neovascularization and skin recovery," say the scientists.
So there is considerable potential for the method. However, as the team emphasizes, it will probably still take a while before the concept is ready for clinical use, because so far there is only proof of general feasibility. Among other things, they will now devote themselves to the task of enlarging the smart patch for use in humans. Another challenge is to design it for mass production in order to keep costs down. It also needs to be clarified how human wounds react to contact with the hydrogel. Despite these hurdles, the developers are optimistic that their system will one day benefit patients with chronic wounds.
Source: Stanford Wearable Electronics Initiative, technical article: Nature Biotechnology, doi: 10.1038/s41587-022-01528-3