Antibacterial nanocoating
Silver and acid will help fight bacteria
Nikolay Podorvanyuk, Indicator
Russian scientists together with Brazilian and Chinese colleagues have created an antimicrobial material based on silver and acid. Its advantage is that it does not contain antibiotics, which means it will not contribute to the appearance of drug resistance in bacteria. The proposed material as part of protective coatings of medical equipment will help prevent the spread of nosocomial infections. The results of the study, supported by a grant from the Russian Science Foundation (RNF), are published in the journal ACS Omega (Novikov et al., Natural Nanoclay-Based Silver–Phosphomolybdic Acid Composite with a Dual Antimicrobial Effect).
Every year there are more and more pathogenic bacteria with resistance to available antibiotics. Although scientists are developing new drugs, pathogens adapt to them as well. Microbes defend themselves in various ways, for example, they produce enzymes that destroy an antibiotic, or change their molecules with which the drug interacts.
It is possible to cope with the development of drug resistance if alternative approaches are used, to which microorganisms will not be able to adapt. So, one of the options is to use special materials, whose mechanism of antimicrobial action is fundamentally different from that of antibiotics. Based on them, it is possible to create coatings for objects through which human contact is inevitable: furniture, door handles, plumbing, touch screens and so on. As a result, pathogens will not accumulate on them and spread further. This is especially important for hospitals, where the ingestion of bacteria into the body of a weakened patient is fraught with severe complications and death.
Scientists from the Gubkin Russian State University of Oil and Gas (National Research University) (Moscow), together with Brazilian and Chinese colleagues, have proposed a new method for obtaining antimicrobial materials. The authors took silver and phosphoric-molybdenum acid as a basis. Silver ions bind to bacterial enzymes that neutralize reactive oxygen species and cause cell death due to oxidative stress. The acid suppresses the ability of bacteria to produce protective enzymes and resist the action of silver ions. The clay mineral galloisite became the carrier for the active components — silver nanoparticles were applied to the surface of its nanotubes, and acid was loaded into their cavity. At the same time, the antimicrobial effect was manifested only when the components were combined, while individually they did not provide the expected result.
The antibacterial effect of the material is activated by wetting — then there is a gradual release of acid and silver ions. The minimum amounts of microbe suppression material were 0.5 g/l for Staphylococcus aureus (Staphylococcus aureus), Pseudomonas aeruginosa (Pseudomonas aeruginosa) and 0.25 g /l for Acinetobacter baumannii ("irakibacter", so named because of frequent infections of wounds of US servicemen in Iraq). These bacteria cause nosocomial infections, including they are widespread in Russia.
Although the concentrations measured in the experiment are higher than those typical for pure antibiotics, the developed materials can be effective for fighting bacteria outside the body, namely to prevent their spread in hospitals.
"The research was inspired by the lines of Boris Grebenshchikov's song: "We know what it's like with silver, let's see what it's like with acid." The resulting material can be used as an additive to protective coatings for medical furniture or instruments. In future studies, we plan to study the antibacterial effect of our system against the formed bacterial biofilm, since the microorganisms in its composition are much easier to develop resistance to antibiotics," comments one of the authors of the article Andrey Novikov, Candidate of Chemical Sciences, associate professor of Gubkin Russian State University of Oil and Gas (NIU).
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