A thin polymer membrane, nano-suit, enhancing survival across the continuum between air and high vacuum

Abstract

Most multicellular organisms can only survive under atmospheric pressure. The reduced pressure of a high vacuum usually leads to rapid dehydration and death. Here we show that a simple surface modification can render multicellular organisms strongly tolerant to high vacuum. Animals that collapsed under high vacuum continued to move following exposure of their natural extracellular surface layer (or that of an artificial coat-like polysorbitan monolaurate) to an electron beam or plasma ionization (i.e., conditions known to enhance polymer formation). Transmission electron microscopic observations revealed the existence of a thin polymerized extra layer on the surface of the animal. The layer acts as a flexible "nano-suit" barrier to the passage of gases and liquids and thus protects the organism. Furthermore, the biocompatible molecule, the component of the nano-suit, was fabricated into a "biomimetic" free-standing membrane. This concept will allow biology-related fields especially to use these membranes for several applications.animal behavior | biophysics | microscopy | nanotechnology | plasma physics

A modified ‘NanoSuit®’ preserves wet samples in high vacuum: direct observations on cells and tissues in field-emission scanning electron microscopy

“…To remove excess water remaining on the surface of the specimens, tissues, untreated and treated with SSE or Tween 20 solution [6], were exposed to low vacuum ( ca 10 Pa) for 1 min 30 s, and then weighed for the first time. During this period, treated specimens were irradiated by plasma to construct the NanoSuit.…”

Embryonic development of Eucorydia yasumatsui Asahina, with special reference to external morphology (Insecta: Blattodea, Corydiidae)

“…The embryonic cuticle wrinkles up during sample processing, separating from the surface due to shrinkage caused by fixation. In such cases, low‐vacuum SEM of noncoated specimens (Machida, ), or ordinary SEM of nonfixed specimens using the nano‐suit method (Takaku et al, ), has substantial advantages. In the case of low‐vacuum SEM, fixed embryos were dehydrated in a graded series of ethyl alcohol, dried using a critical point dryer, and then observed with a low‐vacuum SEM (SM‐300 Wet‐4, TOPCON, Tokyo, Japan) with a pressure of 13 Pa, at an accelerating voltage of 15–20 kV.…”

“…Low‐vacuum SEM of noncoated specimens was also useful for observing micropyles, which are sometimes filled with a dried gelatinous substance. For SEM of nonfixed specimens using the nano‐suit method (Takaku et al, ), embryos were soaked in 1% polyoxyethylene sorbitan monolaurate (Tween 20) solution for 1 hr, mounted on a stub, and observed using SEM under high vacuum with an accelerating voltage of 5 kV, according to the modification by Fujita, Blanke, Nomura, and Machida (). In this method, the embryonic cuticle does not wrinkle up because the embryos suffer from very little shrinkage.…”

Analysis of tea plant resistance to tea green leafhopper, Empoasca onukii, by detecting stylet‐probing behavior with DC electropenetrography

“…() and Takaku et al. () reported that the use of a simple surface coating with a thin layer, termed a ‘NanoSuit,’ can keep organisms alive in high vacuum (10 −5 to 10 −7 Pa) during FE‐SEM. In those studies, live organisms were covered with either a layer of natural extracellular substance (ECS) or an artificial substance mimicking the ECS [e.g., 1% (wt:vol) aqueous solution of the surfactant polyoxyethylene sorbitan monolaurate; TW20]; this substance is then polymerized by plasma or electron beam irradiation.…”