Star-shaped Magnetic-plasmonic Au@Fe3O4 nano-heterostructures for photothermal therapy

Here, we synthesize a Au@Fe3O4 core@shell system with a highly uniform unprecedented star-like shell morphology with combined plasmonic and magnetic properties. An advanced electron microscopy characterization allows assessing the multifaceted nature of the Au core and its role in the growth of the peculiar epitaxial star-like shell with excellent crystallinity and homogeneity. Magnetometry and magneto-optical spectroscopy revealed a pure magnetite shell, with a superior saturation magnetization compared to similar Au@Fe3O4 heterostructures reported in the literature, which is ascribed to the star-like morphology, as well as to the large thickness of the shell. Of note, Au@Fe3O4 nanostar-loaded cancer cells displayed magneto-mechanical stress under a low frequency external alternating magnetic field (few tens of Hz). On the other hand, such a uniform, homogeneous, and thick magnetite shell enables the shift of the plasmonic resonance of the Au core to 640 nm, which is the largest red shift achievable in Au@Fe3O4 homogeneous core@shell systems, prompting application in photothermal therapy and optical imaging in the first biologically transparent window. Preliminary experiments performing irradiation of a stable water suspension of the nanostar and Au@Fe3O4-loaded cancer cell culture suspension at 658 nm confirmed their optical response and their suitability for photothermal therapy. The outstanding features of the prepared system can be thus potentially exploited as a multifunctional platform for magnetic-plasmonic applications

Antioxidants selenomethionine and D-pantethine decrease the negative side effects of doxorubicin in NL/Ly lymphoma-bearing mice

Aim To investigate the potential tissue-protective effects of antioxidants selenomethionine and D-pantethine applied together with doxorubicin (Dx) on NK/Ly lymphomabearing mice. The impact of this chemotherapy scheme on animal survival, blood cell profile, hepatotoxicity, glutathione level, and activity of glutathione-converting enzymes in the liver was compared with the action of Dx applied alone. Methods The hematological profile of animals was studied by the analysis of blood smears under light microscopy. Hepatotoxicity of studied drugs was evaluated measuring the activity of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) enzymes, De Ritis ratio, and coenzyme A fractions by McDougal assay. Glutathione level in animal tissues was measured with Ellman reagent, and the activity of glutathione reductase, transferase, and peroxidase was measured using standard biochemical assays. Results D-pantethine (500 mg/kg) and, to a lower extent, selenomethionine (600 μg/kg) partially reduced the negative side effects (leukocytopenia and erythropenia) of Dx (5 mg/kg) in NK/Ly lymphoma bearing animals on the 14th day of their treatment. This increased animal survival time from 47-48 to 60+ days and improved the quality of their life. This ability of D-pantethine and selenomethionine was realized via hepatoprotective and immunomodulating activities. D-pantethine also restored the levels of acid-soluble and free CoA in the liver of tumor-bearing animals, while selenomethionine caused the recovery of glutathione peroxidase levels in the liver, which was significantly diminished under Dx treatment. Both compounds decreased glutathione level in the liver, which was considerably induced by Dx. Conclusions Antioxidants selenomethionine and D-pantethine partially reversed the negative side effects of Dx in NK/Ly lymphoma-bearing mice and significantly increased the therapeutic efficiency of this drug in tumor treatment

Multiferroic Coupling of Ferromagnetic and Ferroelectric Particles through Elastic Polymers

Multiferroics are materials that electrically polarize when subjected to a magnetic field and magnetize under the action of an electric field. In composites, the multiferroic effect is achieved by mixing of ferromagnetic (FM) and ferroelectric (FE) particles. The FM particles are prone to magnetostriction (field-induced deformation), whereas the FE particles display piezoelectricity (electrically polarize under mechanical stress). In solid composites, where the FM and FE grains are in tight contact, the combination of these effects directly leads to multiferroic behavior. In the present work, we considered the FM/FE composites with soft polymer bases, where the particles of alternative kinds are remote from one another. In these systems, the multiferroic coupling is different and more complicated in comparison with the solid ones as it is essentially mediated by an electromagnetically neutral matrix. When either of the fields, magnetic or electric, acts on the ‘akin’ particles (FM or FE) it causes their displacement and by that perturbs the particle elastic environments. The induced mechanical stresses spread over the matrix and inevitably affect the particles of an alternative kind. Therefore, magnetization causes an electric response (due to the piezoeffect in FE) whereas electric polarization might entail a magnetic response (due to the magnetostriction effect in FM). A numerical model accounting for the multiferroic behavior of a polymer composite of the above-described type is proposed and confirmed experimentally on a polymer-based dispersion of iron and lead zirconate micron-size particles. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Funding: The reported study was funded by the Russian Scientific Foundation according to research project No. 21-72-30032 (experimental investigation and analysis); authors Makarova L.A. and Isaev D.A. acknowledge the President of the Russian Federation Grant Number MK-716.2020.2 (simulation results). Authors Isaenko M.B. and Perov N.S. acknowledge partial support from Lomonosov Moscow State University Program of Development

ДИСТАНЦІЙНЕ НАВЧАННЯ В СИСТЕМІ МЕДИЧНОЇ ОСВІТИ (ПЕРШИЙ ДОСВІД КАФЕДРИ НОРМАЛЬНОЇ ФІЗІОЛОГІЇ ЗДМУ)

The aim of the work – to investigate the feasibility of massive open online courses introducing into the higher medical education system.The main body. The issue of higher education institutions of Ukraine transition from traditional distance learning to massive electronic education on the basis of the online open courses is considered, its relevance is proved. Analysis of the major prerequisites for transition success is carried out (a demand for the educational Internet resources from mobile devices; existence of a large number of various electronic resources which are successfully used in practice by higher education institutions in remote educational technologies; maintaining experience for electronic magazines of students’ progress for planning and estimation of training results; essential growth of material costs in the world online training market). Key issues of transition are defined and the basic principles of electronic online courses development are formulated a technique for electronic online course development aimed as the result is given. The technique contains the following four stages: planning of expected training results, course electronic content structuring and training scenarios creation, development of the tests plan and electronic estimated means for automatic control of the planned training results, course realization by means of game mechanics and technologies of network communication between students. Requirements to various forms of control planned in the course of learning results are defined. Finally, the actual tasks of mass open education development in the leading higher education institutions of Ukraine are set forth.Conclusions. The introduction of massive open online courses allows:1) diversifying the methods of presentation of information, namely the use of text, graphic, illustrated and video materials, which allows the teacher to increase the level of information accessibility to students’ perceptions;2) simplifying the process of control of the final level of knowledge through the system of test control Ratos;3) carrying out differentiation and individualization of training, to provide the choice of an individual trajectory of training;4) providing free access to a large number of visual and teaching materials, which contributes to raising the level of interest in the subject and level of knowledge in general;5) using of modern means of communication between teachers and students allows to diversify forms of education.Мета роботи – дослідження доцільності впровадження масових відкритих онлайн-курсів у систему вищої медичної освіти.Основна частина. У даній статті поставлена проблема переходу вузів України від традиційного дистанційного навчання до масового електронного навчання на основі відкритих онлайн-курсів, обґрунтована її актуальність. Проведено аналіз найважливіших передумов для успішного переходу на даний вид навчання (затребуваність освітніх інтернет-ресурсів, які використовуються з мобільних пристроїв; наявність великої кількості різних електронних ресурсів, які успішно використовуються вузами на практиці в дистанційних освітніх технологіях; наявність досвіду ведення електронних журналів успішності студентів для планування й оцінювання результатів навчання). Визначені ключові завдання переходу до розробки онлайн-курсів.Висновки. Впровадження масових відкритих онлайн-курсів дозволяє:1) урізноманітнити методи подання інформації, а саме використання текстових, графічних, ілюстрованих та відеоматеріалів, що дозволяє викладачеві підвищити рівень доступності інформації до сприйняття студентами;2) спростити процес контролю кінцевого рівня знань за допомогою системи тестового контролю Ратос;3) здійснити диференціацію та індивідуалізацію навчання, забезпечити вибір індивідуальної траєкторії навчання;4) надати вільний доступ до значної кількості наочних та дидактичних матеріалів, що сприяє підвищенню рівня зацікавленості предметом і рівня знань взагалі;5) використання сучасних засобів комунікації між викладачами та студентами дозволяє урізноманітнити форми навчання

Tunable magnetic properties of Ni-doped CoFe2O4 nanoparticles prepared by the sol\u2013gel citrate self-combustion method

The nanostructured spinel ferrites with complex stoichiometry are an important family of the materials in a number of applications, especially in electronics through their good electrical and magnetic properties. In the framework of this study, a set of mixed cobalt and nickel ferrites was prepared with the sol\u2013gel self-combustion route. The structural and morphological features of particles were studied with X-ray diffraction (XRD), Scanning Transmission Electron Microscopy (STEM) and Energy Dispersive X-ray analysis (EDX) techniques. The prepared particles show a crystalline nature with a monotonic distribution of the elements and particles size distribution in the range of 17\u201329 nm. The obtained particles demonstrate good magnetic properties with tunable saturation magnetization and magnetic anisotropy, i.e., coercivity depending on chemical composition

Комп’ютерний прогноз біологічної активності похідних 2-метил(феніл)-6,9-епоксибензо[g]хіноліну-4,5,10-тріону та 5-метил-(1,2,4-тріазоло[4,3-а]хіноліну)

One of the priority measures, which are evaluated in the creation of new effective medicines, is their high selective effect and lack of side effects. A considerable interest is the possibility of combining several structures of heterocycles in one molecule, such as quinoline and furan, which may cause an increase in biological activity of these combined compounds or an emergence of new properties. It is known that derivatives of 1,2,4-triazolo[4,3-a]quinoline have anticonvulsant effect and treat the syndrome of disorders with the nervous system.The aim of research. The main purpose of this work was an establishment of combinatorial library of bioregulators, which combines structures 5,8-dioksoquinoline and furan (1-8), quinoline and triazole (9-12), using computer program PASS (Prediction Activitity Spectra for Substances). Virtual screening of heterocycles derivatives was conducted to determine the direction of their bioactivity researches.Materials and methods. The virtual screening of compounds was performed by using the computer program PASS (Prediction Activity Spectra for Substances). For the specific activity the increase of Pa quantity and the decrease of the Pi quantity, helps to get the greater chance to detect this activity in the experiment.Predicting the probability of substance manifestation of specific types of biological activity determines which tests are the most appropriate for studying the biological activity of specific chemical substances and which substances of those that are available to the researcher likely will show the desired effect. With theoretical prediction the most likely basic structures of new compounds with desired biological effect, which best suits the task will be selected.Results. Analysis of computer prediction demonstrates the promising search of antineoplastic, antibiotic, analgesic and other types of activity in some of these compounds. An important instant of prediction of these substances is their lack of high toxicity terato-, kantsero-, embryo- and mutagenicity.The computer prediction of derivatives of triazole[4,3-a]quinolone had shown that the substitution of hydrogen on the carboxylic acid residue decreases the expected activity, but significantly expands its range and appears new types of biological activity. Injecting the propionic acid residue, you can observe an antieczematic activity, but injecting propylene - antiviral and antiinflammatory activities. Amidation of carboxylic acids leads to a decrease in the activity of "structure-leader" and the emergence of new activities, such as antineurotic, antinociceptive and muscle relaxant.Conclusion. Data of the computer prediction shows us the promising search of the following two directions of bioregulators that can exhibit antineoplastic, antiradical, analgesic, antiinflammatory, diuretic and other biological activities.С целью определения направления исследований биоактивности веществ на основе структур 5,8-диоксохинолина и фурана (1–8), хинолина и триазола (9–12) создана комбинаторная библиотека биорегуляторов с использованием компьютерной программы РАSS (Prediction Activitity Spectra for Substances). Установлено, что из теоретически возможных будут отобраны наиболее вероятные базовые структуры новых соединений с необходимой биологической активностью, которые наиболее удовлетворяют поставленным задачам. Важный момент прогнозирования исследуемых веществ – отсутствие высокой токсичности, терато-, канцеро-, мутагенности. Данные компьютерного прогноза свидетельствуют о поиске среди приведенных двух направлений биорегуляторов, которые могут проявлять антинеопластическую, антирадикальную, анальгетическую, противовоспалительную, диуретическую и другие виды биологической активности.З метою визначення напряму досліджень біоактивності речовин на основі структур 5,8-діоксохіноліну і фурану (1–8), хіноліну і тріазолу (9–12) створили комбінаторну бібліотеку біорегуляторів із використанням комп’ютерної програми РАSS (Prediction Activitity Spectra for Substances). Встановили, що з теоретично можливих будуть відібрані найбільш імовірні базові структури нових сполук із необхідною біологічною активністю, які найбільше відповідають поставленим завданням. Важливим аспектом прогнозування речовин є відсутність високої токсичності, терато-, канцеро-, мутагенності. Дані комп’ютерного прогнозу свідчать про пошук серед наведених двох напрямів біорегуляторів, що можуть проявляти антинеопластичну, антирадикальну, анальгетичну, протизапальну, діуретичну та інші види біологічної активності

Computer prediction of biological activity of 2-methyl(phenyl)-6,9-epoksybenzo[g]quinoline-4,5,10-Trion and 5-methyl-(1,2,4-triazolo[4,3-a] quinoline)

, One of the priority measures, which are evaluated in the creation of new effective medicines, is their high selective effect and lack of side effects. A considerable interest is the possibility of combining several structures of heterocycles in one molecule, such as quinoline and furan, which may cause an increase in biological activity of these combined compounds or an emergence of new properties. It is known that derivatives of 1,2,4-triazolo[4,3-a]quinoline have anticonvulsant effect and treat the syndrome of disorders with the nervous system. The aim of research. The main purpose of this work was an establishment of combinatorial library of bioregulators, which combines structures 5,8-dioksoquinoline and furan (1-8), quinoline and triazole (9-12), using computer program PASS (Prediction Activitity Spectra for Substances). Virtual screening of heterocycles derivatives was conducted to determine the direction of their bioactivity researches. Materials and methods. The virtual screening of compounds was performed by using the computer program PASS (Prediction Activity Spectra for Substances). For the specific activity the increase of Pa quantity and the decrease of the Pi quantity, helps to get the greater chance to detect this activity in the experiment. Predicting the probability of substance manifestation of specific types of biological activity determines which tests are the most appropriate for studying the biological activity of specific chemical substances and which substances of those that are available to the researcher likely will show the desired effect. With theoretical prediction the most likely basic structures of new compounds with desired biological effect, which best suits the task will be selected. Results. Analysis of computer prediction demonstrates the promising search of antineoplastic, antibiotic, analgesic and other types of activity in some of these compounds. An important instant of prediction of these substances is their lack of high toxicity terato-, kantsero-, embryo- and mutagenicity. The computer prediction of derivatives of triazole[4,3-a]quinolone had shown that the substitution of hydrogen on the carboxylic acid residue decreases the expected activity, but significantly expands its range and appears new types of biological activity. Injecting the propionic acid residue, you can observe an antieczematic activity, but injecting propylene - antiviral and antiinflammatory activities. Amidation of carboxylic acids leads to a decrease in the activity of "structure-leader" and the emergence of new activities, such as antineurotic, antinociceptive and muscle relaxant. Conclusion. Data of the computer prediction shows us the promising search of the following two directions of bioregulators that can exhibit antineoplastic, antiradical, analgesic, antiinflammatory, diuretic and other biological activities

Synthesis of magnetic nanoparticles by laser ablation of strontium ferrite under water and their characterization by optically detected magnetophoresis supported by BEM calculations

Measurement of the properties of magnetic nanoparticles is mandatory for their application and usually this is accomplished using magnetometers, like SQUIDs or VSMs. However, these techniques require amounts of materials that are not always available and do not allow exploration of new syntheses with low production. The tiny quantity of nanoparticles obtained by laser ablation of strontium ferrite necessitated the characterization of their magnetic properties using an alternative technique, optically detected magnetophoresis, which exploits the motion of nanoparticles in a fluid under a magnetic field gradient. Time dependent optical extinction of a colloidal solution of magnetic nanoparticles can be used for recording the collective motion of the nanoparticles in a fluid. The optical extinction of nanoparticles, with absorption and scattering contributions, depends on the particle material and on their morphologies. We report a new implementation of a magnetophoretic model with the extinction properties of nanoparticles calculated using the Boundary Element Method. The model is applied to estimate the magnetic properties of a challenging sample of mixed ferrite nanoparticles. The results show that, especially for polydisperse samples, the explicit consideration of the size dependent extinction properties of the nanoparticles is needed to characterize magnetic nanoparticles by optically detected magnetophoresis. The motion of magnetic nanoparticles in a fluid, exploited in many applications, is provided with an appropriate description using the present approach