New 'Silicon Spikes' Can Destroy Almost All Virus Particles
The spikes rip apart some viruses while preventing others from replicating. Both could help prevent the spread of disease.
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New 'Silicon Spikes' Can Destroy Almost All Virus Particles
The spikes rip apart some viruses while preventing others from replicating. Both could help prevent the spread of disease.By Adrianna Nine March 28, 2024
Credit: Mah Et Al, ACS Nano/10.1021/Acsnano.3c07099
When it comes to killing viruses, we typically default to the chemical route. But what about stabbing them? That's the approach researchers in Australia took when they created a spiked silicon material that physically disables viruses. With a 96% success rate, their approach could find a place in hospitals, laboratories, and other disease-averse environments.
From homes to intensive care units, antiviral chemicals—like sanitizing wipes, sprays, and gels—tend to be our go-to disinfectant strategies. But while the occasional wipe-down might be sufficient for low-risk, low-traffic spaces, places like intensive care units and hospital isolation rooms are left to play virus Whac-A-Mole. Most of these spaces are cleaned once or twice daily; though that sounds like a lot, germs are free to propagate on surfaces between wipe-downs. Robots that use ultraviolet light to sanitize hospital rooms are limited to occasional cleaning.
Researchers at the Royal Melbourne Institute of Technology (RMIT) wanted to create a surface that passively keeps disease at bay. To do so, they took inspiration from nature. The wings of some species of dragonflies, cicadas, and other insects feature tiny spikes that fight germs by disabling bacteria and fungi. These spikes are so small that they're invisible to the unaided eye; they exist only on the nanoscale.
Viruses are far smaller than bacteria, so antiviral spikes would have to be smaller than antibacterial spikes. Taking mother nature's lead, the team at RMIT created a silicon surface chock-full of spikes just 290 nanometers tall and 2 nanometers wide. (That's 30,000 times thinner than a human hair, according to RMIT.) The idea was that these spikes would be small enough to pierce viruses, rendering them incapable of replicating and infecting mammals.
Credit: Mah Et Al, ACS Nano/10.1021/Acsnano.3c07099
In a paper for ACS Nano, the researchers describe an experiment comparing the antiviral properties of their spiked surface with that of a smooth silicon plane. On top of both surfaces, they placed human parainfluenza virus type 3 (hPIV-3), the virus behind respiratory illnesses like bronchitis and croup. After just one hour, 74% of the viruses atop the spiked surface had been punctured to the point of incapacitation; at six hours, that figure bumped to 96%. While the viruses atop the smooth control surface gradually lost viability—viruses need living cells to survive long-term and reproduce—they largely retained their physical integrity and took far longer to die.
Because viruses are tougher to kill mechanically than bacteria, the experimental spiked surface was also fairly effective at disabling bacterial cells. RMIT tested the surface's antibacterial properties with Pseudomonas aeruginosa, which can cause meningitis and pneumonia, and Staphylococcus aureus, the bacteria behind staph infections. While the cells on the spiked surface were disrupted at a rate of about 20% and 30%, respectively, the cells on the smooth surface adhered to the material and retained their viability.
In their paper, the team at RMIT says using virus-killing surfaces like their own with common disinfectants should ensure a consistent and near-total (99.99% or more) eradication of infectious viruses on common surfaces. In other words, swapping in a surface with invisible spikes for conventional hospital and lab surfaces could fill the gaps left by occasional disinfectant wipe-downs.
