Novel wound dressing changes colour when it detects an infection

How the dressing works

The team created this specialized wound dressing using "tight mesh nanocellulose." This type of nanostructure keeps bacteria and other microbes out of the wound. 

The main idea is to apply this dressing, which will remain in place throughout the healing process. If the wound becomes infected, the color of the dressing will change. This color change property is determined by the wound's pH. Normal wounds (non-infected) have a pH of about 5.5, but when an infection develops, the pH rises to 8, or even higher. 

The dressing's ability to check pH color change is due to a dye known as bromthymol blue (BTB). This material is loaded onto a dressing made of silica that is only a few nanometres thick. According to the study, when the pH level exceeds 7, the color changes from yellow to blue. 

Doctors can address the infection as soon as it appears by using this new dressing. Infections are typically characterized by the appearance of symptoms such as pus, soreness, or redness. 

Here’s why this development is important  

Our skin is the largest organ of the human body. However, when injured, the wound can impair skin function while also lengthening the healing time.

Infections are more likely to develop in wounds that are difficult to heal. According to the press release, severe wounds account for nearly half of all out-of-hospital costs. 

That is why proper treatment is required to put the wound on the road to a quick recovery.

Furthermore, this novel dressing application may reduce the overuse of antibiotics for wound healing. The dressing can be adequately mixed with an "anti-microbial substance" to reduce the excessive amounts of antibiotics for wound treatment. 

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

The authors estimate that it will take five to 10 years for this development to become mainstream because the product has to pass rigorous medical testing.

Study abstract:

The skin is the largest organ of the human body. Wounds disrupt the functions of the skin and can have catastrophic consequences for an individual resulting in significant morbidity and mortality. Wound infections are common and can substantially delay healing and can result in non-healing wounds and sepsis. Early diagnosis and treatment of infection reduce risk of complications and support wound healing. Methods for monitoring of wound pH can facilitate early detection of infection. Here we show a novel strategy for integrating pH sensing capabilities in state-of-the-art hydrogel-based wound dressings fabricated from bacterial nanocellulose (BC). A high surface area material was developed by self-assembly of mesoporous silica nanoparticles (MSNs) in BC. By encapsulating a pH-responsive dye in the MSNs, wound dressings for continuous pH sensing with spatiotemporal resolution were developed. The pH responsive BC-based nanocomposites demonstrated excellent wound dressing properties, with respect to conformability, mechanical properties, and water vapor transmission rate.