Researchers at RMIT University have used liquid metals to develop a new bacteria-destroying technology that could help address the challenge of antibiotic resistance.
The technology uses nano-sized particles of magnetic liquid metal to shred bacteria and bacterial biofilm – the protective 'house' that bacteria thrive in – without harming good cells.
The research has been published in ACS Nano.
Antibiotic resistance is a major global health threat, causing at least 700,000 deaths every year, with the risk it could overtake cancer as a leading cause of death.
The biggest issues are the spread of dangerous, drug-resistant superbugs and the growth of bacterial biofilm infections, which can no longer be treated with existing antibiotics.
Dr Aaron Elbourne said antibiotics had revolutionised health since they were discovered 90 years ago but were losing effectiveness due to misuse.
“We’re heading to a post-antibiotic future, where common bacterial infections, minor injuries and routine surgeries could once again become deadly,” said Dr Elbourne, a Postdoctoral Fellow in the Nanobiotechnology Laboratory at RMIT.
“It’s not enough to reduce antibiotic use, we need to completely rethink how we fight bacterial infections.
“Bacteria are incredibly adaptable and over time they develop defences to the chemicals used in antibiotics, but they have no way of dealing with a physical attack.
“Our method uses precision-engineered liquid metals to physically rip bacteria to shreds and smash through the biofilm where bacteria live and multiply.
“With further development, we hope this technology could be the way to help make antibiotic resistance history.”
The RMIT team behind the technology is the only group in the world investigating the antibacterial potential of magnetic liquid metal nanoparticles.
When exposed to a low-intensity magnetic field, these nano-sized droplets change shape and develop sharp edges
When the droplets are placed in contact with a bacterial biofilm, their movements and nano-sharp edges break down the biofilm and physically rupture the bacterial cells.
In the new study, after 90 minutes of exposure to the liquid metal nanoparticles, biofilms were destroyed and 99 per cent of the bacteria were dead. Importantly, laboratory tests showed the bacteria-destroying droplets did not affect human cells, said the researchers.
Postdoctoral Fellow Dr Vi Khanh Truong said the versatile technology could one day be used in a range of ways to treat infections.
“It could be used as a spray coating for implants, to make them powerfully antibacterial and reduce the high rates of infection for procedures like hip and knee replacements,” said Dr Truong, currently at North Carolina State University on a Fulbright Scholarship to further the research.
“There’s also potential to develop this into an injectable treatment that could be used at the site of infection.”
The next stage for the research - testing the effectiveness of the technology in pre-clinical animal trials - is underway with the team hoping to move to human clinical trials.
The research was supported by the CASS Foundation, the Australian-American Fulbright Commission and the Jack Brockhoff Foundation.