Tag Archives: Lomonosov Moscow State University

Nanozymes as an antidote for pesticides

Should you have concerns about exposure to pesticides or chemical warfare agents (timely given events in Syria as per this April 4, 2017 news item on CBC [Canadian Broadcasting News Corporation] online) , scientists at the Lomonosov Moscow State University have developed a possible antidote according to a March 8,, 2017 news item on phys.org,

Members of the Faculty of Chemistry of the Lomonosov Moscow State University have developed novel nanosized agents that could be used as efficient protective and antidote modalities against the impact of neurotoxic organophosphorus compounds such as pesticides and chemical warfare agents. …

A March 7, 2017 Lomonosov Moscow State University press release on EurekAlert, which originated the news item, describes the work in detail,

A group of scientists from the Faculty of Chemistry under the leadership of Prof. Alexander Kabanov has focused their research supported by a “megagrant” on the nanoparticle-based delivery to an organism of enzymes, capable of destroying toxic organophosphorous compounds. Development of first nanosized drugs has started more than 30 years ago and already in the 90-s first nanomedicines for cancer treatment entered the market. First such medicines were based on liposomes – spherical vesicles made of lipid bilayers. The new technology, developed by Kabanov and his colleagues, uses an enzyme, synthesized at the Lomonosov Moscow State University, encapsulated into a biodegradable polymer coat, based on an amino acid (glutamic acid).

Alexander Kabanov, Doctor of Chemistry, Professor at the Eshelman School of Pharmacy of the University of North Carolina (USA) and the Faculty of Chemistry, M. V. Lomonosov Moscow State University, one of the authors of the article explains: “At the end of the 80-s my team (at that time in Moscow) and independently Japanese colleagues led by Prof. Kazunori Kataoka from Tokyo began using polymer micelles for small molecules delivery. Soon the nanomedicine field has “exploded”. Currently hundreds of laboratories across the globe work in this area, applying a wide variety of approaches to creation of such nanosized agents. A medicine on the basis of polymeric micelles, developed by a Korean company Samyang Biopharm, was approved for human use in 2006.”

Professor Kabanov’s team after moving to the USA in 1994 focused on development of polymer micelles, which could include biopolymers due to electrostatic interactions. Initially chemists were interested in usage of micelles for RNA and DNA delivery but later on scientists started actively utilizing this approach for delivery of proteins and, namely, enzymes, to the brain and other organs.

Alexander Kabanov says: “At the time I worked at the University of Nebraska Medical Center, in Omaha (USA) and by 2010 we had a lot of results in this area. That’s why when my colleague from the Chemical Enzymology Department of the Lomonosov Moscow State University, Prof. Natalia Klyachko offered me to apply for a megagrant the research theme of the new laboratory was quite obvious. Specifically, to use our delivery approach, which we’ve called a “nanozyme”, for “improvement” of enzymes, developed by colleagues at the Lomonosov Moscow State University for its further medical application.”

Scientists together with the group of enzymologists from the Lomonosov Moscow State University under the leadership of Elena Efremenko, Doctor of Biological Sciences, have chosen organophosphorus hydrolase as a one of the delivered enzymes. Organophosphorus hydrolase is capable of degrading toxic pesticides and chemical warfare agents with very high rate. However, it has disadvantages: because of its bacterial origin, an immune response is observed as a result of its delivery to an organism of mammals. Moreover, organophosphorus hydrolase is quickly removed from the body. Chemists have solved this problem with the help of a “self-assembly” approach: as a result of inclusion of organophosphorus hydrolase enzyme in a nanozyme particles the immune response becomes weaker and, on the contrary, both the storage stability of the enzyme and its lifetime after delivery to an organism considerably increase. Rat experiments have proved that such nanozyme efficiently protects organisms against lethal doses of highly toxic pesticides and even chemical warfare agents, such as VX nerve gas.

Alexander Kabanov summarizes: “The simplicity of our approach is very important. You could get an organophosphorus hydrolase nanozyme by simple mixing of aqueous solutions of anenzyme and safe biocompatible polymer. This nanozyme is self-assembled due to electrostatic interaction between a protein (enzyme) and polymer”.

According to the scientist’s words the simplicity and technological effectiveness of the approach along with the obtained promising results of animal experiments bring hope that this modality could be successful and in clinical use.

Members of the Faculty of Chemistry of the Lomonosov Moscow State University, along with scientists from the 27th Central Research Institute of the Ministry of Defense of the Russian Federation, the Eshelman School of Pharmacy of the University of North Carolina at Chapel Hill (USA) and the University of Nebraska Medical Center (UNC) have taken part in the Project.

Here’s a link to and a citation for the paper,

A simple and highly effective catalytic nanozyme scavenger for organophosphorus neurotoxins by Elena N. Efremenko, Ilya V. Lyagin, Natalia L. Klyachko, Tatiana Bronich, Natalia V. Zavyalova, Yuhang Jiang, Alexander V. Kabanov. Journal of Controlled Release Volume 247, 10 February 2017, Pages 175–181  http://dx.doi.org/10.1016/j.jconrel.2016.12.037

This paper is behind a paywall.

Researchers from Canada and Russia find metal-organic-frameworks in nature

To date, these ‘natural’ metal-organic-frameworks have been found only in Siberian coal mines. From an Aug, 5, 2016 news item on ScienceDaily,

One of the hottest new materials is a class of porous solids known as metal-organic frameworks, or MOFs. These human-made materials were introduced in the 1990s, and researchers around the world are working on ways to use them as molecular sponges for applications such as hydrogen storage, carbon sequestration, or photovoltaics.

Now, a surprising discovery by scientists in Canada and Russia reveals that MOFs also exist in nature — albeit in the form of rare minerals found so far only in Siberian coal mines.

The finding, published in the journal Science Advances, “completely changes the normal view of these highly popular materials as solely artificial, ‘designer’ solids,” says senior author Tomislav Friščić, an associate professor of chemistry at McGill University in Montreal. “This raises the possibility that there might be other, more abundant, MOF minerals out there.”

Caption: Individual crystals of synthetic zhemchuzhnikovite, prepared by Igor Huskić, McGill University. Credit: Igor Huskić, Friščić Research Group, McGill University

Caption: Individual crystals of synthetic zhemchuzhnikovite, prepared by Igor Huskić, McGill University. Credit: Igor Huskić, Friščić Research Group, McGill University

An Aug, 8, 2016 McGill University news release (also on EurekAlert but dated Aug. 5, 2016), which originated the news item, expands on the theme,

The twisting path to the discovery began six years ago, when Friščić came across a mention of the minerals stepanovite and zhemchuzhnikovite in a Canadian mineralogy journal. The crystal structure of the minerals, found in Russia between the 1940s and 1960s, hadn’t been fully determined. But the Russian mineralogists who discovered them had analyzed their chemical composition and the basic parameters of their structures, using a technique known as X-ray powder diffraction. To Friščić, those parameters hinted that the minerals could be structurally similar to a type of man-made MOF.

His curiosity piqued, Friščić began looking for samples of the rare minerals, reaching out to experts, museums and vendors in Russia and elsewhere. After a promising lead with a mining museum in Saint Petersburg failed to pan out, Igor Huskić, a graduate student in the Friščić research group at McGill turned his attention to synthesizing analogues of the minerals in the lab – and succeeded. But a major journal last year declined to publish the team’s work, in part because the original description of the minerals had been reported in a somewhat obscure Russian mineralogical journal.

Then, the McGill chemists caught a break: with the help of a crystallographer colleague in Venezuela, they connected with two prominent Russian mineralogists: Sergey Krivovichev, a professor at Saint Petersburg State University, and Prof. Igor Pekov of Lomonosov Moscow State University.

Krivovichev and Pekov were able to obtain the original samples of the two rare minerals, which had been found decades earlier in a coal mine deep beneath the Siberian permafrost. The Russian experts were also able to determine the crystal structures of the minerals. These findings confirmed the McGill researchers’ initial results from their lab synthesis.

Stepanovite and zhemchuzhnikovite have the elaborate, honeycomb-like structure of MOFs, characterized at the molecular level by large voids. The two minerals aren’t, however, representative of the hottest varieties of MOFs — those that are being developed for use in hydrogen-fueled cars or to capture waste carbon dioxide.

As a result, Friščić and his collaborators are now broadening their research to determine if other, more abundant minerals have porous structures that could make them suitable for uses such as hydrogen storage or even drug delivery.

In any event, the discovery of MOF structures in the two rare minerals already is “paradigm-changing” Friščić says. If scientists had been able to determine those structures in the 1960s, he notes, the development of MOF materials “might have been accelerated by 30 years.”

Here’s a link to and a citation for the paper,

Minerals with metal-organic framework structures by Igor Huskić, Igor V. Pekov, Sergey V. Krivovichev, and Tomislav Friščić. Science Advances  05 Aug 2016: Vol. 2, no. 8, e1600621 DOI: 10.1126/sciadv.1600621

This paper appears to be open access.

Graphene and radioactive waste

In fact, the material in question is graphene oxide and researchers at Rice University (Texas) and Lomonosov Moscow State University have found that it can rapidly remove radioactive material from water  From the Jan. 8, 2013 news item on ScienceDaily,

A collaborative effort by the Rice lab of chemist James Tour and the Moscow lab of chemist Stepan Kalmykov determined that microscopic, atom-thick flakes of graphene oxide bind quickly to natural and human-made radionuclides and condense them into solids. The flakes are soluble in liquids and easily produced in bulk.

The Rice University Jan. 8, 2013 news release, which originated the news item, was written by Mike Williams and provides additional insight and quotes from the researchers (Note: Links have been removed),

The discovery, Tour said, could be a boon in the cleanup of contaminated sites like the Fukushima nuclear plants damaged by the 2011 earthquake and tsunami. It could also cut the cost of hydraulic fracturing (“fracking”) for oil and gas recovery and help reboot American mining of rare earth metals, he said.

Graphene oxide’s large surface area defines its capacity to adsorb toxins, Kalmykov said. “So the high retention properties are not surprising to us,” he said. “What is astonishing is the very fast kinetics of sorption, which is key.”

“In the probabilistic world of chemical reactions where scarce stuff (low concentrations) infrequently bumps into something with which it can react, there is a greater likelihood that the ‘magic’ will happen with graphene oxide than with a big old hunk of bentonite,” said Steven Winston, a former vice president of Lockheed Martin and Parsons Engineering and an expert in nuclear power and remediation who is working with the researchers. “In short, fast is good.”

Here’s how it works (from the news release; Note: Links have been removed),

The researchers focused on removing radioactive isotopes of the actinides  and lanthanides  – the 30 rare earth elements in the periodic table – from liquids, rather than solids or gases. “Though they don’t really like water all that much, they can and do hide out there,” Winston said. “From a human health and environment point of view, that’s where they’re least welcome.”

Naturally occurring radionuclides are also unwelcome in fracking fluids that bring them to the surface in drilling operations, Tour said. “When groundwater comes out of a well and it’s radioactive above a certain level, they can’t put it back into the ground,” he said. “It’s too hot. Companies have to ship contaminated water to repository sites around the country at very large expense.” The ability to quickly filter out contaminants on-site would save a great deal of money, he said.

He sees even greater potential benefits for the mining industry. Environmental requirements have “essentially shut down U.S. mining of rare earth metals, which are needed for cell phones,” Tour said. “China owns the market because they’re not subject to the same environmental standards. So if this technology offers the chance to revive mining here, it could be huge.”

Tour said that capturing radionuclides does not make them less radioactive, just easier to handle. “Where you have huge pools of radioactive material, like at Fukushima, you add graphene oxide and get back a solid material from what were just ions in a solution,” he said. “Then you can skim it off and burn it. Graphene oxide burns very rapidly and leaves a cake of radioactive material you can then reuse.”

The low cost and biodegradable qualities of graphene oxide should make it appropriate for use in permeable reactive barriers, a fairly new technology for in situ groundwater remediation, he said.

Romanchuk, Slesarev, Kalmykov and Tour are co-authors of the paper with Dmitry Kosynkin, a former postdoctoral researcher at Rice, now with Saudi Aramco. Kalmykov is radiochemistry division head and a professor at Lomonosov Moscow State University. Tour is the T.T. and W.F. Chao Chair in Chemistry as well as a professor of mechanical engineering and materials science and of computer science at Rice.

Here’s a ‘before’ shot of solution with graphene oxide and an ‘after’ shot where radionuclides have been added and begun to clump,

A new method for removing radioactive material from solutions is the result of collaboration between Rice University and Lomonosov Moscow State University. The vial at left holds microscopic particles of graphene oxide in a solution. At right, graphene oxide is added to simulated nuclear waste, which quickly clumps for easy removal. Image by Anna Yu. Romanchuk/Lomonosov Moscow State University

A new method for removing radioactive material from solutions is the result of collaboration between Rice University and Lomonosov Moscow State University. The vial at left holds microscopic particles of graphene oxide in a solution. At right, graphene oxide is added to simulated nuclear waste, which quickly clumps for easy removal. Image by Anna Yu. Romanchuk/Lomonosov Moscow State University

As noted in the ScienceDaily news item, the research has been published in the Royal Society’s Physical Chemistry Chemical Physics journal,

Anna Yu. Romanchuk, Alexander Slesarev, Stepan N. Kalmykov, Dmitry Kosynkin, James M Tour. Graphene Oxide for Effective Radionuclide Removal. Physical Chemistry Chemical Physics, 2012; DOI: 10.1039/C2CP44593J

This article is behind a paywall.