According to new research, tiny gold particles could be the next way to fight against bacterial antibiotic resistance.
Researchers have been studying Gold nanoclusters (each made up of roughly 25 atoms of gold) as a way to target and destroy bacterial cells, making them more vulnerable to current antibiotic treatments.
“Antibiotic resistance is rising to dangerously high levels in all parts of the world,” according to a World Health Organization report released last year, which recommended more investment in measures to combat the problem.
Now, a new study led by scientists from the University of Leeds, Southern University of Science and Technology in Shenzhen, and Fudan University in Shanghai, both in China, has discovered a way to package gold nanoclusters in a molecular envelope that reduces their toxicity to healthy tissue while maintaining their antibacterial properties.
Laboratory tests have indicated that the method had a “strong effect” in eliminating a variety of bacteria, including several connected to hospital-acquired infections and resistant to regular antibiotic treatments.
The findings were published in the journal Chemical Science and are based on laboratory research rather than human trials.
Based on the principle that opposite charges attract, the gold nanoclusters were packed in a positively charged ligand. It locates and delivers the nanoclusters to the bacterial cell wall, where they rupture the bacterial cell membrane, much like a carrier pigeon.
The rupture of the cell membrane boosts the bacterial cell’s permeability to traditional antibiotic treatments, reviving drugs that were previously ineffective or fading in their effectiveness against resistant bacteria.
Since each nanocluster is toxic to healthy host mammalian cells, the scientists added a second ligand to the envelope around each nanocluster to shield host cells. These molecules, which have both positive and negative charges, are known as zwitterionic groups, and they can also be found in the lipids of mammalian cell membranes. This makes the gold nanoclusters more compatible with the host mammalian cells and makes it easier for them to pass through the kidney and be eliminated.
The scientists used laboratory studies to see if gold nanoclusters may weaken bacterial cells’ defenses, making them more susceptible to antibiotic treatment.
They employed a methicillin-resistant Staphylococcus epidermidis (MRSE) bacterium strain, which is responsible for several hospital-acquired illnesses.
They evaluated three drugs against MRSE with and without gold nanoclusters, each representing a different antibiotic class.
There was an improved antibacterial effect when the antibiotic was employed in conjunction with the gold nanoclusters. The amount of antibiotics required to prevent MRSE growth was reduced by 128 times with one family of antibiotics.
Dejian Zhou, Professor at Nanochemistry, University of Leeds and one of the supervisors of the research
Professor Dejian Zhou, Professor at Nanochemistry, University of Leeds believes combing gold nanoclusters with existing antibiotics will be a faster and cheaper alternative to developing a host of new antibiotics in response to bacterial antibiotic resistance.
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