Overuse of antibiotics is contributing to the growing global health crisis of antibiotic resistance, which may render one of doctors’ most important weapons against infections ineffective.
A new wound dressing developed by Brown researchers could help fight infections without contributing to antibiotic overuse. In a recent study, researchers created a hydrogel bandage that can detect bacterial enzymes from an infected wound and release antibiotics only as needed.
Anita Shukla, a professor of engineering and the principal investigator for the study, told The Herald that this research started with the question: “How can we provide all the benefits of having a hydrogel dressing but then also try to better control the release of encapsulated antimicrobials?”
Hydrogel wound dressings that release antibiotics are already used clinically, Shukla said.
But “current wound dressings are mostly passive,” Akram Abbasi, the study’s first author and a senior research associate at the School of Engineering, wrote in an email to The Herald. “They either just cover the wound or release medicine at a constant rate regardless of whether an infection is actually present.”
Abbasi wrote in an email to The Herald that this approach “often leads to a burst of medication that tapers off quickly, which can be inefficient and sometimes toxic to healthy tissue.” In addition, this constant release of drugs can cause antimicrobial resistance, as “unnecessary exposure of bacteria to low, non-lethal doses of antibiotics” fuels AMR, she added.
According to Abbasi, the hydrogel developed in this study deals with this issue by encapsulating the antibiotic in tiny sac-like liposomes within the gel to avoid leaking. Only during an active infection will the drug be released, as the presence of bacterial enzymes cause the hydrogel to degrade.
“This precision targeting ensures we use only what is necessary, reducing the chances for bacteria to adapt and develop resistance,” Abbasi wrote.
The researchers developed the hydrogel bandages to target beta-lactamase, an enzyme common in wound infections and produced by many different bacteria.
This enzyme is often produced by drug-resistant bacteria to deactivate antibiotics, Abbasi wrote.
“By choosing this specific signal, we essentially turn the bacteria’s own ‘weapon’ against them,” Abbasi wrote. “The very enzyme they produce to protect themselves is what triggers the breakdown of our hydrogel, releasing the payload that eventually kills them.”
Shukla said that the researchers would be interested in further exploring how to make a hydrogel bandage that is a more holistic healing tool. “The major focus of the formulation was (to) eradicate the infection, but it would be great to see what else we can include to really make this a well-rounded wound repair technology,” she said.
“The modular nature of this technology is very exciting,” Abbasi wrote. “This ‘sense and release’ logic can be adapted to many scenarios,” such as by making hydrogels that release antibiotics in response to other enzymes to target other bacteria or diseases.
“For example, one could design a gel that responds to enzymes overproduced by cancer cells or inflammatory markers in joints,” Abbasi wrote.
According to Camila Carvalho GS, a biomedical engineering Ph.D. candidate who was not an author on the study, the newly developed hydrogels are important since “antimicrobial resistance has been an emerging problem for years now.”
Amrita Rajpal is a senior staff writer covering science and research.
