Combined protection
MSU chemists have created self-cleaning materials for chemical and biological protection
MSU Press Service
Employees of the Department of Chemical Enzymology of the Faculty of Chemistry of Moscow State University with colleagues from NUST MISIS have created multifunctional protective materials that can not only prevent toxins and microbes from entering the skin, but also completely destroy them. To do this, scientists have combined enzymes, antibiotics and metal nanoparticles. The work was published in the International Journal of Molecular Sciences (Lyagin et al., Combined Modification of Fiber Materials by Enzymes and Metal Nanoparticles for Chemical and Biological Protection).
Materials with special protective properties are needed in a variety of industries – from medicine to agriculture. There are several ways to create them. First, you can try to immediately create fibers with protective properties and then produce fabric or non-woven fabric from them. Secondly, you can do the opposite: modify the finished fabric, giving it protective properties. In any case, a material is obtained that does not allow dangerous substances to pass through, detaining them on the surface. At the same time, it is important to remember that toxins do not disappear anywhere from such a material, and do not decompose even with high-temperature, harsh acid or alkaline treatment. Therefore, the scientists went further.
"Our interest was in creating a fabric capable of not only detaining harmful agents, but also destroying them," said the head. Laboratory of ecobiocatalysis of the Chemical Faculty of Moscow State University, Doctor of Biological Sciences, Professor Elena Efremenko. – First of all, we introduced enzymes into the composition of the material that can hydrolyze (and thereby neutralize) a number of toxins. Since our work is mainly aimed at protecting people working in the field of agriculture, organophosphate pesticides and waste products of microscopic fungi (mycotoxins) have become such toxins."
People entering the fields during harvesting always involves contact with plants that were previously treated with organophosphates. It is known that the rejection of these drugs will lead to a decrease in the gross food product by 30% worldwide. Therefore, no genetic manipulation to increase the resistance of plants to insects and weeds can fully replace chemical treatment.
"The problem is that all these pesticides have a nerve–paralytic effect on humans," explained Elena Efremenko. – They can get into the body together with food and liquids, as well as by inhalation and through the skin. After that, they begin to accumulate in human tissues and organs. This poses a great threat to the harvesters. It is known that about three hundred thousand people die annually from pesticide poisoning. Control is being carried out, but the problem of accumulation cannot be solved."
In addition to chemical protection, the authors set themselves the task of protecting a person from the effects of bacteria. An effective solution in this case was the addition of antibiotics to a material already containing enzymes that decompose toxins. To obtain a tissue with comprehensive protection, it is necessary to use an antimicrobial drug that combines well with an enzyme, otherwise the components will negatively affect each other.
"With the help of computer modeling methods, we tried to find such a pair," explained Elena Efremenko. – It was important for us to use a biodegradable antibiotic that will not pollute the environment, but at the same time will be able to act well and will not inactivate the enzyme. We went even further: we took an enzyme that can neutralize not only toxins, but also signaling molecules produced by bacteria to enhance their resistance to antibiotics. So the enzyme helps the antimicrobial drug to destroy bacteria."
Bacteria are designed so that over time they can acquire resistance to the action of an antibiotic, but they are not able to protect themselves from metals. The authors discovered for the first time that tantalum nanoparticles can be successfully applied. On the one hand, they cause the death of many bacteria, and on the other – they have no biological activity and will not affect the human body.
"In order to find out the residual amounts of microbes and toxins on the tissues, we had to develop a special technique, because it is impossible to find out by traditional methods of microbiology," Elena Efremenko said. – We carried out the extraction of ATP molecules, the concentration of which reflects the metabolic activity of the cell. Their content is a characteristic similar to human body temperature. It expresses something cumulative from all the processes occurring in cells: if the concentration of ATP drops sharply and strongly, we can safely talk about their death. So we were able to track the efficiency of our tissues when applying microorganisms to them. As a result, we managed to achieve almost complete destruction of microbes and toxins on the processed materials."
Now the new material is undergoing patenting.
Portal "Eternal youth" http://vechnayamolodost.ru