Open wounds are something of a paradox – they need to be checked regularly, yet taking the dressing off too often just increases the risk of infection. That's why a group of Swiss researchers has developed a new "glowing" bandage that lets caregivers monitor the healing progress of wounds, from the outside.
Known as Flusitex (Fluorescence sensing integrated into medical textiles), the technology is being developed by a team consisting of scientists from Swiss research group EMPA, ETH Zurich, Centre Suisse d'Electronique et de Microtechnique (CSEM) and University Hospital Zurich. Here's how it works ...
When a wound is healing normally, the pH of its fluids initially rises to 8, before settling down to 5 or 6. Should it become chronic, however, the pH fluctuates between 7 and 8.
The bandage incorporates custom-made molecules composed of benzalkonium chloride and pyranine. These fluoresce when exposed to pH levels of around 7.5 – the chronic wound "sweet spot." In order to see that fluorescence, clinicians just need to shine an ultraviolet light on the dressing. They can then leave the dressing in place if normal healing is indicated.
As a side benefit, the benzalkonium chloride in the bandage is known to kill harmful Staphylococcus aureus bacteria.
Hopefully, it may someday even be possible to "read" the fluorescence just using a smartphone camera and app, potentially allowing patients to monitor their own progress at home.
Empa is now working with some industrial partners to commercialize Flusitex. Once on the market, it could face some competition from DermaTrax, which is another bandage that monitors pH to assess the healing of wounds.