Can protective clothing be reused without disinfection?

The difference between human acetylcholinesterase and insects is not big enough.

—— Jiang Tao, Senior Engineer, Biology Research Center, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences

Nerve agents based on organophosphorus are one of the most toxic chemicals known to man

"This research work in the zirconium-organic molecular framework, increased the crosslinking of polyethyleneimine epoxides, and developed a hydrogel that can be maintained under ventilated conditions, which can nearly instantaneously hydrolyze several typical organophosphates.

Toxic mechanism similar to insecticides

Nerve agents are often discolored, so how do organophosphorus-based nerve agents cause harm to humans?

In this regard, Jiang Tao explained that organophosphates (OPs) are a general term for a class of chemical pesticides, and their main function is to covalently modify the acetylcholinesterase (AChE) of insects to produce a Inhibition

"Animal nerve conduction depends on the neurotransmitter between nerve synapses-acetylcholine and its receptor

Jiang Tao analyzed that if acetylcholinesterase is combined with organophosphorus pesticides, resulting in loss of activity, acetylcholine cannot be removed in time, a large amount of acetylcholine accumulates at synaptic sites, acetylcholine receptors in the postsynaptic membrane are continuously activated, and postsynaptic nerve fibers Be in a state of excitement for a long time

In fact, the research on acetylcholinesterase has a history of more than 70 years, and there are more than 20,000 related scientific papers

"The difference between human acetylcholinesterase and insects is not great enough.

Physical protection is the primary line of defense

In the face of organophosphorus nerve agents, humans usually use physical protection and drugs to detoxify

Jiang Tao explained that human protection against organophosphorus pesticides is first of all physical protection, such as using gas masks or even full-body protective clothing to prevent the inhalation of poisons and their skin contact

For poisoned higher animals, organophosphorus pesticides first poison the liver and kidneys and cause severe abdominal pain.

Experts analyze that organophosphorus pesticides can be poisoned by inhalation or absorption through the skin

Therefore, Jiang Tao said that the pesticide authority of the Chinese government has banned the use of highly toxic organophosphorus pesticides in an orderly manner

"After organophosphorus pesticides are poisoned, detoxification can be done as soon as possible with drugs such as pralidoxime, which can remove the organophosphorus-modified part from the acetylcholine ester, and roughly restore the quantity and activity of acetylcholine esters.

In 2018, a project involving US Army chemical and biological experts reported for the first time that it systematically studied the effectiveness of the solvolysis of organophosphorus compounds using MOFs

"The results show that the use of organic framework methanol gel with zirconium as the central metal can solvate several organophosphorus compounds that simulate chemical weapons (chemical warfare agents) without consuming this zirconium-organic framework compound, which is originally used as a structure.

New materials are easy to use on protective clothing

This year, Northwestern University’s Institute of Chemistry and International Nanotechnology, the U.
S.
Army’s Combat Capability Development Command Chemical Biology Center, and Northwestern University’s Department of Chemistry and Biological Engineering jointly published a paper entitled "Zirconium-based Metal-Organic Framework Hydrogel Composite Material Nearly Instant Catalytic hydrolysis of organophosphorus nerve agent"
.

Unlike the existing powdered MOF absorbent material, this hydrogel material does not require the addition of water, so it is more convenient to use on protective masks or clothing
.
Omar Farha, a professor of chemistry at Northwestern University and the corresponding author of the paper, said: "The use of chemical weapons in recent global conflicts reflects the urgent need for personal protective equipment and the urgency of mass destruction of chemical weapons stockpiles
.
In this work, we will MOFs and amine-containing cross-linked hydrogels are integrated into the fabric to establish an appropriate microenvironment, which in turn promotes the rapid degradation of nerve agents and provides real-time protection
.
"

Although MOFs have previously proven their ability to quickly decompose organophosphorus preparations and similar analogues in the laboratory, it has been proved that these powder adsorbents are difficult to integrate directly into protective cloths
.
When the neurotoxin binds to the zirconium 6 cluster, it usually deactivates the powder and fiber composite catalyst
.
This shortcoming requires the use of alkaline solutions to regenerate the catalytic sites of MOFs, which will not prevent MOFs from being used to eliminate stored chemical weapons, but will hinder their use in protective equipment
.

To overcome this challenge, Farha and colleagues designed a MOF-based fabric composite system that uses water in an amine-based hydrogel to break down nerve agents
.

"The protective clothing containing this kind of hydrogel on the surface can hydrolyze the organophosphorus warfare agent it comes into contact with, which means that the surface protective clothing does not need to be disinfected, and it can be reused only by ensuring the water in the gel
.
This is compared with the usual protective clothing.
The clothes must be disinfected and thoroughly cleaned and verified before they can be reused, which has certain advantages
.
” Jiang Tao explained
.

"The research originated from the chemistry of metal-organic compounds, and has continued to grow since the 1960s, branching out metal-organic compounds, transition metal organic compounds, metal cluster compounds, transition metal cluster compounds, metal-organic framework compounds, etc.
, From pure basic research, new molecular products with practical significance or potential functions
have been developed.
” Jiang Tao pointed out that this shows an important feature of scientific and technological development.
When conducting basic research, I don’t know what will be discovered tomorrow, let alone the future development.
What else will it bring? Scientists study and upgrade the structure of a molecule, which will also bring unexpected new functions.
Science and technology complement each other, and continue to obtain theoretical and innovative results
.
(Reporter Ma Aiping)