Medical

Liquid metal shredder kills superbugs without drugs

Liquid metal shredder kills su...
A microscope image of the liquid metal nanoparticles, which may be a promising new form of treatment against antibiotic-resistant bacteria
A microscope image of the liquid metal nanoparticles, which may be a promising new form of treatment against antibiotic-resistant bacteria
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A microscope image of the liquid metal nanoparticles, which may be a promising new form of treatment against antibiotic-resistant bacteria
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A microscope image of the liquid metal nanoparticles, which may be a promising new form of treatment against antibiotic-resistant bacteria
Golden Staph bacteria (left), and the aftermath of exposure to the liquid metal nanoparticles (right)
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Golden Staph bacteria (left), and the aftermath of exposure to the liquid metal nanoparticles (right)

One of humanity’s biggest threats is also the smallest – bacteria. With antibiotic resistance on the rise, we may be heading towards a future where even minor infections become lethal again. But now, researchers at RMIT in Australia have found a new method for killing these superbugs that they can’t resist – magnetic nanoparticles that physically tear them to shreds.

The ability for populations of bacteria to develop resistance to drugs is basic evolution. When a patient takes antibiotics, the majority of the offending bacteria will be wiped out – but not all of them. Some individuals will have random genetic mutations that let them survive the onslaught, and since they’re now the only ones left, these genes will be passed onto their offspring. In time, that resistance trait becomes the norm for that species, and the drug becomes ineffective against them.

Over the decades, the solution to this problem has been to develop new antibiotics, but the pipeline is beginning to run dry. New drugs are always in development, but it’s never enough, it takes too long, and they often don’t stay effective for very long. It’s clear that other methods are needed.

Enter the RMIT team. Rather than fight with chemicals, which bacteria will almost always develop resistance to, the researchers set out to find ways to physically attack the bugs. After all, humans, for example, could evolve resistance to mild poisons over time, but not being stabbed.

The team’s solution was to use magnetic, liquid metal nanoparticles. When exposed to a low-intensity magnetic field, these droplets change their shape, with their edges becoming sharp enough to puncture cell walls and biofilms – the sturdy, sticky substance that colonies of bacteria build to protect themselves from antibiotics.

Golden Staph bacteria (left), and the aftermath of exposure to the liquid metal nanoparticles (right)
Golden Staph bacteria (left), and the aftermath of exposure to the liquid metal nanoparticles (right)

In the lab, the team tested the new technique against bacterial biofilms. After 90 minutes, the biofilms were destroyed, as were 99 percent of the bacteria. This was shown to work against both main types of bacteria – gram-positive and gram-negative – and thankfully, didn’t harm human cells.

“Bacteria are incredibly adaptable and over time they develop defenses to the chemicals used in antibiotics, but they have no way of dealing with a physical attack,” says Aaron Elbourne, an author of the study. “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 team says that the technology could be used as a spray coating for medical implants and instruments to keep them sterile, or potentially as an injectable treatment straight into the site of an infection. In the long run, it could be adapted to work against fungal infections, cholesterol plaques and even cancer.

As promising as it sounds, it’s very early days – the team is just now beginning to test the technology in pre-clinical animal trials, so it’ll be a while before human trials begin, if ever. Still, it could become a fascinating physical approach to the problem, alongside systems like materials, electrified graphene surfaces and decontaminating light.

The research was published in the journal ACS Nano.

Source: RMIT

12 comments
Worzel
That seems really clever! Human life depends on bacteria, so if these bacteria shredding nano particles get into the food chain, as all other human ''wonder materials'' have, you can probably say 'bye bye' humans, and probably all other animal life on this planet.
paul314
Bacteria have evolved to live in acids, in sub-freezing conditions where ice crystals would normally puncture their cell walls, in near-boiling liquids. If pointy magnetic liquids become a thing natural selection will probably eventually figure out a way around it. But anything that slows them down for a few million generations is probably a good idea.
piperTom
The researchers say "liquid metal" with no explanation. Am I wrong to think of mercury?
RobC
Sorry to pile on the skepticism because we do need new ways to fight bacteria. But, I always cringe when I see quotes like "After 90 minutes, the biofilms were destroyed, as were 99 percent of the bacteria." 99% is how bacteria always seem to form resistance. Where is the 100% approach?
guzmanchinky
Nanoparticles. Not long ago this was a go to word for science fiction writers. Amazing science...
minivini
I’m eager to find out if these nano particles pass through or are accumulated in the liver and/kidneys...
Yakov Dragunov
The very thought of converting my body to an 'industrial ball mill' akin to a small scale cement grinder is viscerally not appealing. If this process in a testtube at this point grinds apart all kinds of cells to the extinction of ALL life bearing cell walls in a test... well ... WE are MADE of .....CELLS. Just whose son and heir thought up this and did not think it through?
Sam RI Digsby MD
Doctors were curing diseases such as syphilis back during the American civil war with silver injections less the silver salts (a difficult preparation compared to penicillin). The alien told me it's actually the electrons that destroy the pathogens. The key is to have the electrons spinning the same direction as the good stuff and counter the bad stuff. And, there is no resistance.
Eric Blenheim
Alfred Searle experimented with a large number of different metals and elements producing colloids and sols effective in treating various health conditions, with silver confirmed as being a marvellous antibiotic.
He wrote the following book, which has only become widely available again in recent years;
The use of colloids in health and disease
by Alfred B. Searle
Published 1920 by Constable in London https://ia802706.us.archive.org/32/items/useofcolloidsinh00searuoft/useofcolloidsinh00searuoft.pdf
Signguy
Pure Copper in the form of a small bar of soap kills bacteria/germs on the hands. A good thing to use after shopping/handling money...