Can you imagine a smart bandage that can heal your wounds at a fast pace? Researchers from Stanford University have developed a wireless smart bandage that can speed up tissue repair, monitor the wound healing process, and treat the wound simultaneously. The study describing the findings was recently published in the journal Nature Biotechnology.
The wireless bandage is a saviour for many people because some wounds simply do not heal. Moreover, healing could be slowed due to infections, diseases like diabetes or suppressed immune systems.
It is important to heal chronic wounds fast because if they last months, they can lead to anxiety and depression, and can be life-threatening in the worst cases.
How does the new smart bandage work?
Solutions for treating chronic wounds had been rare so far, before the new research by Stanford University. The wireless smart bandage promotes faster closure of wounds, increases new blood flow to injured tissue, and enhances skin recovery by significantly reducing scar formation.
The wireless circuitry inside the smart bandage can monitor the progression of wound healing using impedance (resistance) or temperature sensors. The sensors inform a central processing unit to apply more electrical stimulation across the wound bed, if the wound is less healed or an infection is detected. The electrical stimulation will accelerate tissue closure and reduce infection. Since the bandage uses wireless circuitry, researchers were able to track the sensor data in real time on a smartphone.
What is special about the new smart bandage?
The bandage consists of an electronic layer which is just 100 micrometres thick. The electronic layer has a microcontroller unit (MCU), radio antenna, biosensors, memory and an electrical stimulator. It is as thick as a single coat of latex paint.
The circuitry is located above a cleverly engineered hydrogel, which is a rubbery, skin-like polymer. The hydrogel and circuitry are integrated to both deliver healing electrical stimulation to the injured tissue and collect real-time biosensor data.
Scientists have carefully designed the polymer in the hydrogel so that it adheres securely to the wound surface when needed. Also, the hydrogel can be pulled away cleanly and gently without harm to the wound when warmed to just a few degrees above body temperature, around 40 degrees Celsius.
According to a statement released by Stanford Wearable Electronics Initiative, electrical stimulation, also known as galvanotaxis, has been found to proactively promote tissue growth and help with tissue repair by accelerating the migration of keratinocytes to the wound sites, preventing the development of biofilms on wound surfaces, and limiting bacterial infections. The researchers integrated this well-studied technology with real-time biosensor data to provide a novel automated treatment modality that is informed by biosensors.
The smart bandage can provide a real-time, rapid, robust and extremely accurate way to measure wound conditions through its biosensing capabilities, which can monitor biophysical changes in the local environment.
The smart bandage senses conductivity and temperature changes in the skin as the wound heals, the statement says. As wounds heal, electrical impedance increases, and as inflammation subsides, local temperature declines.
Why and how does electrical stimulation heal wounds faster?
In order to understand why and how electrical stimulation heals wounds faster, the researchers conducted further analyses. According to the statement, the researchers believe that electrical stimulation promotes the activation of pro-regenerative genes such as Selenop and Apoe. Selenop is an anti-inflammatory gene that has been found to help with pathogen clearance and wound repair. Apoe is a gene which has been shown to increase muscle and soft tissue growth.
The study also found that electrical stimulation increased the amount of white blood cell populations, namely monocytes and macrophages, through the recruitment of greater amounts of M2 anti-inflammatory macrophages. These macrophages are pro-regenerative and play a key role in the extracellular matrix formation that is required during the proliferative phases of wound healing.
Challenges to clinical use of the smart bandage
While smart bandage is currently a proof of concept, it is a promising one. However, many challenges remain, including increasing the size of the device to human scale, solving long-term data storage issues, and reducing cost. These steps are necessary to scale up the bandage to mass production.
The researchers could add some new sensors which measure pH, metabolites and biomarkers.
Hydrogel rejection, in which the skin may react to the device and create a bad gel-to-skin combination, and biofouling of the sensors, which can cause irritation, are some other hindrances to clinical use.
Nevertheless, the researchers are hopeful that the smart bandage can help patients by treating chronic wounds.