RUDN chemists synthesized a chitosan multifunctional composite material
Chitosan, which is derived from chitin, the main substance in the shells of crustaceans and other arthropods, is interesting for “green chemistry” because of several properties. It is made from available raw materials, and the materials made from it are generally biocompatible, non-toxic, and easily degradable under natural conditions. In addition, they are polymers, long molecules-chains of repeating links, the modification of which allows you to give the material new properties.
“In previous studies, we were able to obtain a chitosan-based polymer with both catalytic and antibacterial properties using ultrasound treatment. It is known that the integration of metal ions into the polymer matrix makes it possible to strengthen such materials and improve their characteristics. The most suitable metal compounds for modifying our materials are complexes with divalent zinc, which also exhibits antibacterial and catalytic activity,” Andrey Kritchenkov, PhD, assistant of the RUDN Department of Inorganic Chemistry.
At the first stage of the experiment, the researchers compared the new approach to the synthesis of chitosan derivatives with the standard one. Using ultrasound allowed RUDN chemists to obtain a derivative of chitosan and iodine-containing aromatic aldehyde much faster than under conventional conditions. To 60% of the original units of chitosan joined hydrocarbon rings aldehyde, it took 10 minutes instead of three hours. In addition, ultrasound reduced the volume of aldehyde required for the reaction by 2.6 times. The reaction temperature in both cases did not exceed 25°C. The chitosan derivative was then treated with a small amount of zinc chloride and caustic soda. A composite material was formed in which each chitosan link carried an aldehyde-derived ring of atoms and a zinc cation.
For comparison, RUDN chemists synthesized a similar composite with the inclusion of zinc from pure chitosan. The catalytic effect of the new materials was evaluated in a three-component Mannich reaction, which allows simultaneously forming a new bond between carbon atoms and adding a functional group to the compound. The composite based on a chitosan derivative proved a more effective catalyst compared to both zinc-modified chitosan and inorganic zinc compounds. At the same time, the new material can be used in catalysis six times in a row due to its resistance to high temperature. In tests of antibacterial properties, the new composite was compared with the same catalytic agents as well as with the antibiotics ampicillin and gentamicin. All substances proved to be detrimental to E. coli (Escherichia coli) and Staphylococcus aureus bacteria, but the medical drugs were nevertheless two or more times more effective.
“The composite material based on a chitosan derivative with zinc showed impressive catalytic properties and antibacterial activity comparable to that of known antibiotics. To find out how these qualities are related to the structure of the material, we continue the project and synthesize similar materials in reactions with other aldehydes”, says Andrey Kritchenkov, PhD, assistant of the RUDN Department of Inorganic Chemistry.
The article was published in Aquaculture Mendeleev Communications.
Imagine a world where everyone has enough food, clean water, access to education, and decent work. A world where nature is protected and the future of our planet is cared for. These are the Sustainable Development Goals—to achieve a sustainable future for all! To this end, in 2015, the United Nations (UN) defined 17 Sustainable Development Goals (SDGs). The SDGs are a global plan that helps countries and people work together towards a better future. All 193 UN member states have joined the plan.
Researchers from the Faculty of Artificial Intelligence at RUDN University conducted a large-scale study that revealed systemic errors in large language models (LLMs) when diagnosing depression based on text. This work, carried out in collaboration with colleagues from AIRI, Federal Research Center “Computer Science and Control” of the Russian Academy of Sciences, Ivannikov Institute for System Programming of the Russian Academy of Sciences, Moscow Institute of Physics and Technology, and MBZUAI, not only identifies the problem but also lays the foundation for the creation of more reliable and secure tools for detecting depression and anxiety.
Alexandra Sentyabreva, a junior researcher at the Laboratory of Cell Technologies and Tissue Engineering at RUDN Research Institute of Molecular and Cellular Medicine at the Russian University of People's Friendship, won the competition for young scientists at the All-Russian Scientific Conference “Topical Issues of Morphogenesis in Norm and Pathology.” She was awarded the Academician A.P. Avtsyn Prize.
Imagine a world where everyone has enough food, clean water, access to education, and decent work. A world where nature is protected and the future of our planet is cared for. These are the Sustainable Development Goals—to achieve a sustainable future for all! To this end, in 2015, the United Nations (UN) defined 17 Sustainable Development Goals (SDGs). The SDGs are a global plan that helps countries and people work together towards a better future. All 193 UN member states have joined the plan.
Researchers from the Faculty of Artificial Intelligence at RUDN University conducted a large-scale study that revealed systemic errors in large language models (LLMs) when diagnosing depression based on text. This work, carried out in collaboration with colleagues from AIRI, Federal Research Center “Computer Science and Control” of the Russian Academy of Sciences, Ivannikov Institute for System Programming of the Russian Academy of Sciences, Moscow Institute of Physics and Technology, and MBZUAI, not only identifies the problem but also lays the foundation for the creation of more reliable and secure tools for detecting depression and anxiety.
Alexandra Sentyabreva, a junior researcher at the Laboratory of Cell Technologies and Tissue Engineering at RUDN Research Institute of Molecular and Cellular Medicine at the Russian University of People's Friendship, won the competition for young scientists at the All-Russian Scientific Conference “Topical Issues of Morphogenesis in Norm and Pathology.” She was awarded the Academician A.P. Avtsyn Prize.