Abstract: α-Cobratoxin is the main neurotoxin in the cobra Naja kaouthia venom; it binds efficiently and selectively with neuronal α7 and muscle type nicotinic acetylcholine receptor and can be used for specific labeling and visualization of these receptors in organs and tissues. For these applications we have prepared conjugates of α-cobratoxin with CdSe quantum dots which have many benefits as compared to organic fluorescent labels. To prepare the conjugate, CdSe quantum dots with ZnS shell were functionalized using a tripeptide glutathione and coupled to toxin using water soluble carbodiimide. The conjugate was purified by gel-filtration chromatography and tested for biological activity. It was found that conjugate preserved the capacity to interact with both neuronal α7 and muscle type nicotinic acetylcholine receptor. Its cytotoxicity to mammalian cells was not higher than that of functionalized quantum dots.
Abstract: For the first time nanostructured engineering ceramics were prepared from natural zirconia mineral (baddeleyite) with CaO as a tetragonal phase stabilizer. The effect of synthesis conditions on microstructure and mechanical properties of the baddeleyite-based ceramics is reported, furthermore, the effect of calcia content on hardness and fracture toughness is studied. Optimal calcia concentration and synthesis conditions are found, corresponding hardness and fracture toughness values are 10,8 GPa and 13,3 MPa×m1/2. The reported mechanical properties are comparable to those typically reported for yttria-stabilized engineering zirconia ceramics, prepared from chemically synthesized zirconia.
Abstract: In the present work porous scaffolds for trabecular bone defects replacement were studied. PLA and PLA/HA сomposites were obtained by extrusion. Scaffolds were obtained by 3D-printing by fused filament fabrication method. Long-term creep and Charpy impact tests show that PLA/HA scaffolds with the maximum force for destruction at impact of 119 N can function under a load of up to 10 MPa without shape changing and loss of mechanical properties. In vivo tests were used to investigate biocompatibility of scaffolds. The scaffolds may be used as implants for unloaded small bone defects replacement
Abstract: The present work aims at implementing heat accumulators in real technological processes and poses a problem of practical importance.Heat accumulators have been the subject of laboratory research for a long time. Several authors have obtained certain results while studying such devices, but only few of them have considered their introduction into the industrial practice. In this regard, the present research provides two directions for applying heat accumulators: thermotherapy and methane tanks.The need to stabilize temperature conditions is common to these processes. To achieve this goal, graphene-modified sodium acetate (thermal conductivity ≈5,000 W/(m K))was used herein as heat accumulator with controlled discharge mode (heat dissipation). The possibility of improving the stability of sodium acetate when introducing graphene thereinto was established. Besides,charge/discharge modes were investigated under the operating conditions of thermotherapy and methane tanks.
Abstract: One of the main reasons for limiting the widespread clinical use of mesenchymal stem cells (MSCs) is a low speed of their proliferation in vitro. In this regard, the search for new safe and effective growth stimulants is an urgent task. In this study, we investigated the effect of nanocrystalline cerium oxide doped with gadolinium (Ce1-х Gdх Oy), on the morphofunctional characteristics and proliferative activity of MSCs derived from dental pulp. It was shown that the introduction of Ce1-х Gdх Oy nanoparticles into the culture of dental MSCs provides the activation of proliferation of the cells in a dose-dependent manner. High concentrations of Ce1-х Gdх Oy nanoparticles inhibit the proliferation of the cells; however, this does not lead to further development of apoptosis and cell death. The obtained results indicate that the nanocrystalline cerium oxide can be considered as a basis for the development of highly efficient and low-cost supplements for culturing MSCs.
Abstract: Three types of nanoparticles, quantum dots (QDs), gold particles (GPs), and latex particles (LPs), were compared as labels for immunochromatographic assay. The influence of the nature of the label on the analytical performance of the test systems was studied using the example of detection of the antibiotic chloramphenicol (CAP). The limits of detection of CAP are 0.1 ng/mL for QDs, 2.4 ng/mL for GPs, and 0.3 ng/mL for LPs. The unique structure and physical properties of the QD fluorescent labels ensure their competitive advantage over colorimetric labels. The proposed methodology is applicable to determination of characteristics of other nanodisperse labels.
Abstract: New compositions of dental adhesives with nanoparticles of metals were developed, in order to achieve prolonged bactericidal properties. The studies were conducted on the culture of dental plaque. The observation period was 24 - 27 days. Further research was not possible due to the drying of wells with adhesives. Tantalum, aluminum, silver, vanadium, iron and copper nanoparticles were chosen as antimicrobial additives. It is shown that changing the mode of electric discharge dispersion-condensing device in a narrow range does not affect the antibacterial efficacy of the final product - the dental adhesive. It is found that tantalum nanoparticles increase the average value of shear strength in the system "filling material - adhesive - dentin" more than 40%.
Abstract: In this study, new types of nanogold labels for lateral flow immunoassay of model antigen procalcitonin based on photometric and surface-enhanced Raman scattering methods of detection were obtained. The linear range of procalcitonin determination applying gold nanoflowers as a label was between 0.5 and 10 ng/mL. The limit of photometric detection was achieved at 0.1 ng/mL that was five times lower than the sensitivity of traditional lateral flow immunoassay with spherical gold nanoparticles as a label. In addition, the conjugate of polyclonal antibodies against procalcitonin with spherical gold nanoparticles labeled with 4-mercaptobenzoic acid as Raman reporter molecule was prepared and used as an immunoprobe in lateral flow immunoassay based on surface-enhanced Raman spectroscopy to improve assay sensitivity.
Abstract: Magnetic nanoparticles (MNP) are efficient molecular carriers for affine molecules. MNP complexes with antibodies can be used for the selective concentration and highly sensitive detection of various compounds. In this paper, development steps of the enzyme immunoassay using MNP are considered in details. Simple method of MNP synthesis and production of conjugates of antibodies with the aggregated MNP using physical sorption is presented. Simple, yet effective, formats of enzyme immunoassay are given. Using aflatoxin B1 detection as an example, possibility of decreasing detection limit up to 2 pg/mL, with a considerable decrease in the assay time, and performing immune interaction in the media with high organic content is shown.