A nanocellulose wound dressing that can reveal early signs of infection without interfering with the healing process has been developed by researchers at Linköping University. Their study, published in Materials Today Bio, is one further step on the road to a new type of wound care.
The skin is the largest organ of the human body. A wound disrupts the normal function of the skin and can take a long time to heal, be very painful for the patient and may, in a worst case scenario, lead to death if not treated correctly. Also, hard-to-heal wounds pose a great burden on society, representing about half of all costs in out-patient care.

In traditional wound care, dressings are changed regularly, about every two days. To check whether the wound is infected, care staff have to lift the dressing and make an assessment based on appearance and tests. Tw researchers in an lab sitting at a table.

New type of wound care
Researchers at Linköping University, in collaboration with colleagues from Örebro and Luleå Universities, have now developed a wound dressing made of nanocellulose that can reveal early signs of infection without interfering with the healing process.

“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. 
Early detection
Non-infected wounds have a pH value of about 5.5. When an infection occurs, the wound becomes increasingly basic and may have a pH value of 8, or even higher. This is 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.

To make the wound dressing show the elevated pH value, the researchers used bromthymol blue, BTB, a dye that changes colour from yellow to blue when the pH value exceeds 7. For BTB to be used in the dressing without being compromised, it was loaded onto a silica material with pores only a few nanometres in size. Three plates with different colours (blue, green and yellow).
The wound dressing changes colour from yellow to blue when the wound is infected.
 Reduce the use of antibiotics
Wound infections are often treated with antibiotics that spread throughout the body. But if the infection is detected at an early stage, local treatment of the wound may suffice. This is why Daniel Aili and his colleagues at Örebro University are also developing anti-microbial substances based on so-called lipopeptides that kill off all types of bacteria.

Source: https://liu.se/en/news-item/sarforbandet-som-avslojar-infektion