Водорастворимые магнитные наночастицы как потенциальные агенты для магнитной гипертермии

Magnetic nanoparticles (MNPs) obtained by two methods - thermal decomposition of iron(V) pentacarbonyl and polyol synthesis - were characterized with the use of dynamic/electrophoretic light scattering and high resolution transmission electron microscopy. The obtained MNPs were tested as potential agents for magnetic hyperthermia by measuring their ability to cause water dispersion heating in an electromagnetic field.Магнитные наночастицы (МНЧ), полученные двумя методами: термическим разложением пентакарбонила железа(0) и методом полиольного синтеза, были охарактеризованы с использованием динамического/электрофоретического светорассеивания (ДСР/ЭСР) и просвечивающей электронной микроскопии высокого разрешения (ПЭМ). Полученные МНЧ были опробованы как потенциальные агенты для магнитной гипертермии путем измерения их способности вызывать нагрев водной дисперсии в переменном электромагнитном поле

Using enhanced number and brightness to measure protein oligomerization dynamics in live cells

Protein dimerization and oligomerization are essential to most cellular functions, yet measurement of the size of these oligomers in live cells, especially when their size changes over time and space, remains a challenge. A commonly used approach for studying protein aggregates in cells is number and brightness (N&B), a fluorescence microscopy method that is capable of measuring the apparent average number of molecules and their oligomerization (brightness) in each pixel from a series of fluorescence microscopy images. We have recently expanded this approach in order to allow resampling of the raw data to resolve the statistical weighting of coexisting species within each pixel. This feature makes enhanced N&B (eN&B) optimal for capturing the temporal aspects of protein oligomerization when a distribution of oligomers shifts toward a larger central size over time. In this protocol, we demonstrate the application of eN&B by quantifying receptor clustering dynamics using electron-multiplying charge-coupled device (EMCCD)-based total internal reflection microscopy (TIRF) imaging. TIRF provides a superior signal-to-noise ratio, but we also provide guidelines for implementing eN&B in confocal microscopes. For each time point, eN&B requires the acquisition of 200 frames, and it takes a few seconds up to 2 min to complete a single time point. We provide an eN&B (and standard N&B) MATLAB software package amenable to any standard confocal or TIRF microscope. The software requires a high-RAM computer (64 Gb) to run and includes a photobleaching detrending algorithm, which allows extension of the live imaging for more than an hour

Water-soluble magnetic nanoparticles as potential agents for magnetic hyperthermia

Magnetic nanoparticles (MNPs) obtained by two methods - thermal decomposition of iron(V) pentacarbonyl and polyol synthesis - were characterized with the use of dynamic/electrophoretic light scattering and high resolution transmission electron microscopy. The obtained MNPs were tested as potential agents for magnetic hyperthermia by measuring their ability to cause water dispersion heating in an electromagnetic field

Impact of Mixed Xenogeneic Porcine Hematopoietic Chimerism on Human NK Cell Recognition in a Humanized Mouse Model

Mixed chimerism is a promising approach to inducing allograft and xenograft tolerance. Mixed allogeneic and xenogeneic chimerism in mouse models induced specific tolerance and global hyporesponsiveness, respectively, of host mouse natural killer (NK) cells. In this study, we investigated whether pig/human mixed chimerism could tolerize human NK cells in a humanized mouse model. Our results showed no impact of induced human NK cell reconstitution on porcine chimerism. NK cells from most pig/human mixed chimeric mice showed either specifically decreased cytotoxicity to pig cells or global hyporesponsiveness in an in vitro cytotoxicity assay. Mixed xenogeneic chimerism did not hamper the maturation of human NK cells but was associated with an alteration in NK cell subset distribution and interferon gamma (IFN-gamma) production in the bone marrow. In summary, we demonstrate that mixed xenogeneic chimerism induces human NK cell hyporesponsiveness to pig cells. Our results support the use of this approach to inducing xenogeneic tolerance in the clinical setting. However, additional approaches are required to improve the efficacy of tolerance induction while ensuring adequate NK cell functions

A Facile Chemical Synthesis of PbTe Nanostructures at Room Temperature

Thermoelectric (TE) materials are possible solutions of the current problems in the energy sector to overcome environmental pollution, increasing energy demand and the decline of natural resources. Thermoelectric materials are a promising alternative for the conversion of waste heat to electricity. Nanocrystalline PbTe powder was synthesized by a simple chemical method at room temperature and systematically investigated at various durations as samples A1–A5. Fourier Transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), microstructural analysis by scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) confirmed the composition of the samples. TE parameters as thermo-emf of samples A1–A5 and electrical conductivity were measured. The cyclic voltammetry gives a band gap of 0.25 eV, which is in agreement with the optical band gap of the material. The A4 sample has an average crystal size of 36 nm with preferred orientation in (200) verifying the cubic morphology. The obtained TE parameters are beneficial for the non-uniform TE materials which might be due to strong current boundary scattering and extremely low thermal conductivity of the samples