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Nanosuit Protects Small Animals From Vacuum

04/16/2013
Ashley Yeager

A plasma-irradiated polymer nanosuit can keep small animals like mosquito larva alive even in the high-vacuum conditions of a scanning electron microscope. Learn more...


Move over Iron Man. A new nanosuit can keep you alive in high-vacuum conditions similar to space. That is, as long as you’re a mosquito larva or other similarly-sized organism.

A plasma-irriated polymer nanosuit can keep small animals like mosquito larva alive even in the high-vacuum conditions of a scanning electron microscope. Source: PNAS




The polymer suit was created with an electron beam and the emulsifying agent polysorbate-20, also known as Tween-20. With this new suit of armor, small animals were able to survive in the low-pressure conditions of a scanning electron microscope (SEM).

The unexpected surface shielding ability "suggests the potential of making very significant advances in space biology," said Takahiko Hariyama, a biologist at the Japan Science and Technology Agency in Kawaguchi and author of a paper published this week in the Proceedings of the National Academy of Science that describes the nanosuit (1).

Past studies have shown that extremophiles, such as the desiccation-tolerant larvae of the fly Polypedilum vanderplanki, can survive extreme low-pressure conditions by entering into an ametabolic state. But when exposed to an SEM vacuum, these organisms suffer immediate collapse, dehydration, and death.

Of course, that was all before the Tween-20 nanosuit. “We could now show that with the nano-spacesuit, their natural appearance remains intact and these animals are able to survive,” Hariyama said.

Inspiration for the nanosuit came from an experiment involving Drosophila larvae. When the larvae were placed in an SEM vacuum with an electron beam, they survived; without the electron beam, they shriveled and died.

By looking at high-magnification images, Hariyama and colleagues found the irradiated larvae had developed an intricate, wrinkled surface structure. The team hypothesized that the electron beam provided the extra energy required to induce molecules in the larvae’s extracellular matrix to form covalent bonds, thus creating long polymer chains. The chains then cross-linked to one another, encapsulating the larvae in a polymer "shield” protecting them from dehydration and death.

To test their theory, the scientists used plasma irradiation to show that ionized particles could provide the energy necessary for polymer formation in the larvae’s surface layer.

They then created an artificial suit for organisms that could not create their own protective polymer layer. To do this, the group dipped the flatworm Dugesia japonica, the ant Pristomyrmex punctatus, and the amphipod crustacean Talitrus saltator in a 1% solution of Tween-20, irradiated them in plasma, and placed them in an SEM. They all survived.

“If the commonly occurring electrons and plasma [and the extracellular surfaces] are able to construct a shield to preserve life, many organisms have the potential to attain this ability,” Hariyama said.

Overall, their nanosuits protected the larvae from the detrimental effects of high-vacuum conditions for about 30 minutes. But this strategy may also provide scientists with a new way to image other organisms and even live tissue with an SEM.

Reference

1. Takaku, T. et al. 2013. A thin polymer membrane, nano-suit, enhancing survival across the continuum between air and high vacuum. PNAS. April 15: 1-5.

Keywords:  microscopy biophysics