Frontiers of scientific research: New "smart bandages" help solve the treatment of chronic wounds

How can a doctor ensure that a bandaged wound is healing without removing the bandage? This is a conundrum because removing the bandage can disrupt the healing process. The techniques presented in a new study in the open access journal Frontiers in Physics may be helpful.

This new "smart bandage" contains a sensor that can very sensitively measure the humidity level of the wound and then transmit the data to a nearby smartphone without the need for a doctor to remove the bandage. In the future, by changing the geometry and material of the bandage, researchers may be able to fine-tune it to suit different types of wounds. The technology can help doctors monitor wounds more easily and successfully.

For patients who have experienced chronic wounds, chronic wounds can be a source of severe pain and disability. Getting such a wound to heal is tricky, and there are many factors that affect wound healing, such as temperature, glucose levels, and acidity. However, one of the most important factors is the moisture content. Too dry, the tissue would become dry; too wet, it would become white and wrinkled, just like in a bathtub. Both of these conditions can disrupt the healing process.

However, if doctors want to check the moisture content of the wound, they need to remove the bandage, which can damage the fragile healing tissue. These questions inspired this latest smart bandage as a non-invasive way to monitor wound moisture levels. The choice of material was a challenge as the bandages needed to be biocompatible, disposable, and inexpensive.

How does it work?

To achieve this, the researchers used a technique called screen printing to apply a conductive polymer called poly(3,4-ethylenedioxythiophene): polystyrene sulfonate (PEDOT:PSS) to gauze, and then combined the gauze with commercially available bandage material. The idea is that a change in the humidity level of the wound causes a change in the electrical signal measured by the sensor.

"PEDOT:PSS is an organic semiconductor polymer that can be easily deposited on a wide range of substrates as a standard ink," explains study author Dr Marta Tessarolo of the University of Bologna. We've also added an inexpensive, disposable, bandage-compatible RFID tag to our textile patches, similar to the one used for clothing safety tags. The tag can wirelessly transmit humidity data with smartphones, letting healthcare workers know when a bandage is needed to change. ”

To test their bandages, the researchers exposed them to artificial wound exudate, which is the fluid that oozes from the wound, and also tested different bandage materials and shapes. They found that the bandage was highly sensitive, providing very different readings in dry, wet and saturated conditions, suggesting that it could be a valuable tool for wound management.

"We developed a series of bandages with different layers and different absorption characteristics and properties," said Dr. Luca Possanzini, another author at the University of Bologna. "The idea is that each type of wound can have its own suitable dressing, from slowly oozing wounds to wounds with high exudation, such as burns and blisters. However, we need to further optimize the sensor geometry and determine the appropriate sensor values for the best results. Heal before we can apply our technique to various types of wounds. ”