Nanocellulose wound dressing changes colour to indicate infection

The dressing, described in Materials Today Bio, has been developed by researchers at Linköping University in collaboration with colleagues at Örebro and Luleå Universities, Sweden.

“Being able to see instantly whether a wound has become infected, without having to lift the dressing, opens up for a new type of wound care that can lead to more efficient care and improve life for patients with hard-to-heal wounds,” said Daniel Aili, professor in the department of Biophysics and Bioengineering at Linköping University. “It can also reduce unnecessary use of antibiotics.”

The dressing is made of tight mesh nanocellulose that prevents ingress of bacteria and other microbes. The material simultaneously lets gases and liquid through, which is important to wound healing. Once applied, the dressing is intended to stay on during the entire healing process. Should the wound become infected, the dressing will show a colour shift.

Non-infected wounds have a pH value of about 5.5 but when an infection occurs the wound becomes increasingly basic and may have a pH value of 8 or higher because bacteria in the wound change their surroundings to fit their optimal growth environment. An elevated pH value in the wound can be detected long before any pus, soreness or redness, which are the most common signs of infection.