Researchers find cicada wing structure able to kill bacteria on contact (w/ video)

Mar 06, 2013 by Bob Yirka report
Cicada (P. claripennis) wing surface topography. Credit: Biophysical Journal, doi:10.1016/j.bpj.2012.12.046

(Phys.org) —A combined team of researchers from Spain and Australia has discovered what they claim is the first known instance of a biomaterial that can kill bacteria on contact based only its physical surface structure. In their paper published in Biophysical Journal, the team describes how they found that clanger cicadas have nanoscale sized pillars on their wings that trap and slowly kill bacteria by pulling their cells apart.

Under a microscope, the team reports, the wings of the clanger cicada show a landscape hostile to bacteria—vast arrays of blunted spikes. When bacteria land on the spikes, they don't pop, as might be expected, instead, they stick and are slowly torn apart as their cell skin descends to the wing surface between the spikes. It works because at least some bacteria have elastic skin.

It's similar to a water balloon landing on a bed of blunt nails. The nails aren't sharp enough to pierce the balloon's skin, but over time, as the weight of the water inside the balloon pushes the skin between the spikes, causing it to stretch, tears eventually develop, causing the balloon to deflate, or in the case of the bacteria on the cicada's wing, death.

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To make sure they understood what was actually going on with the cicada's wings and the bacteria that landed on them, the researchers cooked some bacteria in a microwave to cause different degrees of elasticity in their skin. Those specimens were then dropped onto a to see what would happen—unsurprisingly, those that were more elastic were torn apart, while those that were more rigid, were not. It's the first time anyone's seen a fend off bacteria using nothing more than the shape of their .

Such a finding is of course exciting to those that study , and perhaps to everyone else as it may lead to the development of materials that could be used to perform the same action for us, though not as an extension of our own bodies of course. Coverings could be made for countertops, doorknobs or hand rails, etc., to kill bacteria and/or viruses on contact without having to resort to polluting bioagents.

Additional videos: www.youtube.com/watch?v=KSdMYX4gqp8 and www.youtube.com/watch?v=eIwj_ThMf4Q

Explore further: Technique for quantification of erythrocyte zinc protoporphyrin IX and protoporphyrin IX

More information: Biophysical Model of Bacterial Cell Interactions with Nanopatterned Cicada Wing Surfaces, Biophysical Journal, Volume 104, Issue 4, 835-840, 19 February 2013, doi:10.1016/j.bpj.2012.12.046

Abstract
The nanopattern on the surface of Clanger cicada (Psaltoda claripennis) wings represents the first example of a new class of biomaterials that can kill bacteria on contact based solely on their physical surface structure. The wings provide a model for the development of novel functional surfaces that possess an increased resistance to bacterial contamination and infection. We propose a biophysical model of the interactions between bacterial cells and cicada wing surface structures, and show that mechanical properties, in particular cell rigidity, are key factors in determining bacterial resistance/sensitivity to the bactericidal nature of the wing surface. We confirmed this experimentally by decreasing the rigidity of surface-resistant strains through microwave irradiation of the cells, which renders them susceptible to the wing effects. Our findings demonstrate the potential benefits of incorporating cicada wing nanopatterns into the design of antibacterial nanomaterials.

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antialias_physorg
4.3 / 5 (6) Mar 06, 2013
Should be considered for hospital surfaces.

Coverings could be made for countertops, doorknobs or hand rails, etc., to kill bacteria and/or viruses on contact without having to resort to polluting bioagents.

I think this would (unfortunately) not work on viruses.
DGBEACH
5 / 5 (6) Mar 06, 2013
Even more interesting is what might have led them to even LOOK at a cicada's wings in the first place...fascinating
!
Tausch
1 / 5 (1) Mar 06, 2013
Are there cicadas?*
*Without this.

If not, genetically modified them to have a surface without this.
This is your control group when testing for bacterial resistance.
manifespo
5 / 5 (2) Mar 06, 2013
Antialias is right. This likely would not work to deactivate viral particles, nor prions.

Copper remains the winner by far, in regards to antimicrobial action.

Still an impressive discovery of bio material characterization.
soo
5 / 5 (2) Mar 06, 2013
Seems that this would lead to bacteria evolving a less elastic skin eventually.
antialias_physorg
4.2 / 5 (5) Mar 07, 2013
Seems that this would lead to bacteria evolving a less elastic skin eventually.


They do. That's for example what happens when you apply acne cream. The bacteria that survive are the ones with thicker membranes.

The downside (for the bacteria) is: Thicker membranes cost a lot more energy to make. Hence such bacteria grow/divide at a much slower rate (and this is why, when you stop using acne cream you suddenly get a 'super-infection'. All that 'food' is there, but no or only slowly competing bacteria. So any 'normal' acne bacteria that resettle are suddenly in paradise and can multiply enormously. So you have to use acne cream again. This cocaine-effect is what keeps the acne cream industry in business. using soap is better. While it does not remove ALL bacteria it prevents complet razing and development of the hardier strains.)

As always: a little dirt in your environment is better than perfect sterility.
Torbjorn_Larsson_OM
5 / 5 (1) Mar 07, 2013
It could work on *some* viruses, the ones that uses the host eukaryote cell membrane as part of their packaging. They too would be trapped and at least the outer surface torn. Even trapping would help reduce viral load.
Dr Tom
5 / 5 (1) Mar 09, 2013
This is very interesting although I am not sure if these structures were evolutionarily driven because of their antimicrobial nature. I suspect the flexible cell walls mentioned may be from gram negative bacteria. If so, I wonder if it would work on Gram positive bacteria or the envelope viruses mentioned.

I believe IBM made a similar observation with the surface constructed by photolithography.

Copper was mentioned as a better antimicrobial, unfortunately this is not entirely true. The material I am currently working on, Nouvex, achieves a three log kill in 10 minutes on a solid surface rather than copper's two hours. It is persistent as well.
Isaacsname
4 / 5 (1) Mar 10, 2013
Brings to mind several questions:

1. Only on cicada wings ?
2. For what purpose ?

Isaacsname
not rated yet Mar 11, 2013
Knowing that things like butterfly wings have " nano-biological " ability to harvest heat from sunlight, would this anti-bacterial ability have anything to do with preventing bio-film buildup ?

?