China scientists make bacteria-beating bandage to outsmart superbugs
- Researchers say the ‘test-to-treat’ smart dressing can identify and treat drug-resistant bacteria as well as common infections
- Hydrogel layer placed against a wound changes colour within three hours if an infection is present, they say
The research team from China’s Northeastern University (NEU) said its “test-to-treat” bandage pad can be used anywhere, at any time using a simple colour code, according to the paper published in peer-reviewed journal ACS Nano this month.
The researchers, led by NEU professors Song Yan-yan and Ding Chen, developed a double-layered hydrogel bandage, with a green layer that changes to yellow within three hours of being placed against a wound if an infection is present.
If the pad remains yellow, a drug-sensitive (DS) bacterial infection is present which can be treated by placing another hydrogel layer on top of the first pad to release a commonly used antibiotic into the wound.
But a further colour change to red indicates the presence of drug-resistant (DR) bacteria – the so-called superbugs that are posing an increasing challenge in the fight against infectious diseases.
These can be treated by adding a hydrogel layer that generates toxic reactive oxygen species (ROS) – one of the main therapeutic options available to combat antibiotic-resistant infections – when triggered by movement or massage.
“To rapidly detect and accurately treat highly complex DS/DR bacterial wound infections, the design possesses multifunctions, such as visual sensing, self-driving therapy, and high antibacterial efficiency,” Song said.
The bandage works on the principle that any bacterial growth will create an acidic environment at the infection site and react with the first hydrogel pad to turn it yellow. The same pad will continue to change colour to red if the additional enzyme commonly present in DR bacteria is detected.
“The hydrogel pad is capable of detecting both DS and DR bacteria within three hours. The colour change is observed even at a low concentration for both DS and DR bacteria,” Song said in the paper, adding that a higher bacterial concentration induces a more obvious red colour.
When a DR infection is present, another hydrogel layer is used to combine a photocatalyst with a mechanoluminescent material to transform mechanical force – such as massage, stretching and touch – into visible or near-infrared light.
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The action generates the ROS – a superoxide that attacks the bacteria’s DNA, proteins and lipids, leading to cell death – in a controllable and effective way, according to the researchers.
“This multifunctional design effectively reduces antibiotic abuse and accelerates wound healing, providing an innovative and promising Band-Aid strategy in point-of-care diagnosis and therapy,” Song said.
“It possesses high potential for low-cost and easy-operation wound dressing in rapid detection and smart treatment, without extra ancillary equipment and is convenient to use at home.”
