The use of manganese-doped mesoporous silica nanopowder for targeted drug delivery

The researched manganese-doped mesoporous silica nanopowder (SiO 2 -MnO 2 NP) was produced using evaporation caused by a pulsed electron beam in a vacuum. The synthesized material demonstrated high porosity, amorphous structure and magnetic properties increased with the addition of dopant. The evaluation of the sedimentation stability of NP suspensions showed the need for the additional stabilization. It was established that increasing the sonication time, as the way to increase stability, leads to changes in the structure of the NP. PEG stabilized suspensions showed the highest stability. Experimental results indicated that for different drugs individual methods of loading and release are required. Drug loaded NP demonstrated a high drug loading capacity of 0.09 mg Amoxicillin per mg NP, 0.075 mg Doxorubicin per mg NP that is five times higher than loading capacity of chemically synthesized NP. © Published under licence by IOP Publishing Ltd.This work was performed within a support of the Russian Science Foundation No. 16-16-04038)

Production of Nanopowders of Bismuth Oxide Doped with Silver by Pulsed Electron Beam Evaporation in Vacuum

Various bismuth containing compounds are promising in many applications, including for creating photocatalysts based on them using a visible range of light. However, strong polymorphism (9 polymophic phases of Bi2O3), thermal instability and changes in the properties of bismuth oxide during long-term storage significantly complicate work with it. One way to increase stability and improve photocatalytic properties is by doping Bi2O3 with various metals. Ag doped Bi2O3 nanoparticles (NPs) are typically produced using chemical techniques often associated with the presence of toxic chemicals. The present paper used an environmentally friendly method of producing NPs using the method of pulsed electron beam evaporation in vacuum. The evaporation target was obtained by solid phase synthesis in an electric furnace on air using silver nitrate additives (1 and 5 wt.%).Textural, thermal and magnetic properties of the obtained NPs have been studied. Was found that the Ag-Bi2O3 NPs have a specific surface area (SSA) of 23.7 m2/g, which was almost 2 times bigger than the SSA of the pure Bi2O3 (13.2 m2/g) obtained previously. The thermal stability of the Ag-doped Bi2O3 samples was maintained to the temperature 350°C. While further heating on air took place the phase transition β → α. © 2021 Institute of Physics Publishing. All rights reserved.Authors are grateful to the research scientist of IMF UB RAS, to PhD Gaviko V.S. for XRD NPs. The reported study was funded by RFBR and GACR, project number 20-58-26002

Production of Nanopowder of Cerium (III) Fluoride Obtained by Pulsed Electron Beam Evaporation in Vacuum

The method of pulsed electron beam evaporation in vacuum was first used to obtain CeF3 nanopowder (NP). During NP production, a high evaporation rate of the target (~ 7 g/h) and a higher percentage of NP collection (> 72%) were observed, both for fluoride and the previously obtained CeO2 oxide. It was found that the produced NP contains two crystalline phases: hexagonal CeF3 (95 wt.%, coherent scattering region ≈ 8 nm and [Ce-O-F] or [Ce-F]. The magnetic susceptibility of CeF3 nanoparticles (NPles) coincides with the susceptibility of micron particles, indicating the potential for using such NPles as a contrast agent for tomography. High specific surface area (CeO2-270 m2/g, CeF3 – 62 m2/g), large pore volume (0.35-0.11 cm3/g) allow the use of NPles as nanocontainers for drug delivery. © 2021 Institute of Physics Publishing. All rights reserved.The reported study was funded by RFBR and GACR, project number 20-58-26002

Formation of Droplets in a Heterophasic Amorphocrystalline Nanopowder Bi2O3 Produced by Pulsed Electron Beam Evaporation in Vacuum

In the present work, a mesoporous multiphase amorphous crystal nanopowder Bi2O3 with a specific surface area of up to 23 m2/g was produced by pulsed electron beam evaporation in vacuum. Influence of thermal annealing (200-500 C) of powders in air is investigated. The formation of droplets with a size of 3-5 nm on the surface of all large nanoparticles constituting the framework 3D nanopowder agglomerates was found due to extrusion of liquid bismuth from the volume during cooling. © Published under licence by IOP Publishing Ltd.The study was carried out with the financial support of RFFI and the Czech Science Foundation as part of scientific project No. 20-58-26002

Physicochemical characterization and antioxidant properties of cerium oxide nanoparticles

Studies of the biological activity of cerium oxide nanoparticles (CONPs) show that this compound exhibits antioxidant, antitumor, antibacterial and antiviral properties. The CONPs were obtained by pulsed electron evaporation in a low-pressure gas with a specific surface area of ∼ 190 m 2 /g. Strongly-noequilibrium conditions of synthesis led to the formation of high defect structures, which makes it possible to change the Ce 3+ /Ce 4+ ions ratio and, consequently, to enhance the level of their biological activity. To analyze the content of cerium with different valences, X-ray photoelectron spectroscopy was performed. To determine the enzyme-like activity of CONPs, a chemical analysis of the interaction with hydrogen peroxide was carried out on a spectrophotometer. The results show a significant presence of Ce 3+ in CONPs and the inhibition of reactive oxygen species (ROS). The valence of the cerium atoms determines the chemical activity of CONPs; thus, in a more alkaline medium, the CONPs decrease the ROS concentration, while in the acidic medium its activity diminishes. By varying the parameters of the nanopowders obtained and achieving the optimum Ce 3+ /Ce 4+ ratio, one can produce CONPs having properties which enable the creation of pharmaceuticals for protection against ROS or for combating tumors, viruses and bacteria. © Published under licence by IOP Publishing Ltd.This work was performed within a support of the Russian Science Foundation project [16-16-04038]

Time course of changes in the development of gait disorders in multiple sclerosis

Objective: to estimate the time course of changes in foot biomechanical function as multiple sclerosis (MS) progresses in patients with different degrees of disability compared to a control group. Patients and methods. To estimate the time course of changes in gait disorders in MS, changes in foot biomechanical function were explored in 30 patients with relapsing-remitting MS. Their neurological status was evaluated using the expanded disability status scale (EDSS); pedographic examination was made applying a plantar pressure distribution system; all the patients were examined twice. During the first examination, the patients were divided into two groups: 1) minimal neurological disorders (EDSS scores of < 3.0) and 2) moderate ones (EDSS scores of ≥3.0). Results and discussion. The patients with a mild neurological deficit showed increases in foot load and its lateralization by elevating pressure on the heads of the fourth and fifth metatarsal bones, as evidenced by a significant rise in mean pressure, maximum force, and force-time integral. These changes occurred in the absence of the patients’ complaints of changes in movements. Pedographic examination revealed the changes indicating an enlarged anterior transverse arch and the lower role of the hallux in body weight transfer in the patients with a moderate neurological deficit despite the fact that there were no further visible negative changes in a motor process or progression in neurological deficit. The pedographic examination makes it possible to estimate the degree of gait disorders caused by pyramidal and/or cerebellar lesions and to identify a leading role of this or that functional system in their genesis. Pyramidal dysfunction has impact on the pressurization of the heads of the second and third metatarsal bones. Computed pedography can identify clinically subtle movement changes and estimate the time course of changes in movement disorders in MS patients, including those to evaluate the efficiency of therapy and rehabilitation measures

Modifying the Surface of Cerium Oxide Nanopowders Produced by Physical Method

The work was supported by Russian Science Foundation project № 18-72-00041. The authors are grateful to A. N. Kiryakov (Ural Federal University) for assistance in luminescence measurements

Modifying the surface of cerium oxide nanopowders produced by physical method

Cerium oxide nanoparticles present an interesting material for different industrial applications in biotechnology and medicine. The CeO2 nanopowder was produced by the method of pulsed electron evaporation of ceramic oxide targets with condensation of the vapors in a low pressure gas. The modification of nanoparticle surface was made with sodium citrate and N-phosphonomethylaminodiacetic acid. The stable aqueous suspensions of CeO2 nanoparticles could not be obtained in the work. This is probably due to the high hydrophobic properties of the nanoparticle surface. The cerium oxide nanoparticles with different stabilizers exhibit luminescence properties. © 2019 Author(s)

Gd2O3, SiO2-Gd2O3 and SiO2-MnO2 nanoparticles as potential MRI contrast agents

Gd2O3, SiO2-Gd2O3 and SiO2-MnO2 nanoparticles were produced by the method of pulsed electron evaporation of oxide targets with condensation of the vapors in a vacuum. These materials are considered as probable contrast agents for magnetic resonance imaging (MRI). The Gd2O3 nanoparticles exhibit a rather high r1 and r2 relaxivities. These results point to the potential of using nanocrystals for MRI diagnosis. The mesoporous nanostructures SiO2-Gd2O3 and SiO2-MnO2 could be considered as multimodal theranostic agents. © 2020 IOP Publishing Ltd