Репозиторий Университета

© 2018 Istituto Superiore di Sanita. All Rights Reserved. Parkinson disease is one of the common age-related motor neurodegenerative diseases, in which dopamine neurons degeneration is considered to be pathognomic for the development of motor disfunction. Brain-derived neurotrophic factor (BDNF) is a member of the neurotrophin family, which is considered to be a key regulator of neuronal plasticity. BDNF, being a large molecule, does not pass through the blood-brain barrier (BBB). Synthetic polymer nanoparticles (NP), covered by surfactant, provide the phenomenon of “Trojan hoarse” and enable BDNF to penetrate into the brain tissue. For modelling of parkinsonism we used an intraperitoneal (i.p.) injection of neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) which was injected to the C57BL/6 mice with subsequest treatment with normal saline (group 1), BDNF (group 2), nanoparticulate BDNF (group 3) and surfactant-coated nanoparticulate BDNF (group 4). After 90 min, 24 hours, 72 hours and 7 days manifestations of parkinsonism were evaluated using behavioural tests of open field, rota-rod, assessment of the tremor, length of the body and pace. At the end of experiment the brain was sampled for histological evaluation of changes in the striatum and midbrain and concentration of BDNF in the brain tissues. The results of the experiments demonstrated that nanoparticulate BDNF covered with surfactant significanltly reduced rigidity of the skeletal muscles, oligokinesia and tremor, and also significantly increased BDNF concentration in the brain tissues.

© 2018 Trans Tech Publications, Switzerland  This paper presents the results of experimental studies of arrays of Ag 0.52 Au 0.48 alloy nanoparticles. Arrays were formed by vacuum-thermal evaporation on an unheated substrate and subsequent low-temperature vacuum annealing. The TEM images of the obtained nanoparticle arrays and corresponding histograms of particle size distribution are shown. The transmission spectra of these arrays showing the displacement of the plasma frequency as a function of the mean particle size are obtained. Spectra of Raman scattering from a thin film of amorphous carbon in presence of AgAu particles are obtained, and a comparative analysis of Raman scattering amplification factors for pure Ag, pure Au and Ag 0.52 Au 0.48 alloy nanoparticles is presented.

© 2018, Nizhny Novgorod State Medical Academy. All rights reserved. The aim of the study was to demonstrate the possibility of real-time tracking of polyethylenimine-coated NaYF4 :Yb,Tm upconversion nanoparticles (UCNPs) in living cancer cells using wide-field microscopy technique. Materials and Methods. Human breast adenocarcinoma SK-BR-3 cells and Yb3+ , Tm3+ doped NaYF4 nanoparticles with anti-Stokes photoluminescence were used in the study. The nanoparticles were visualized using wide-field microscope with excitation at 975 nm and signal detection in 420–842 spectral range. The analysis of the displacement of UCNPs was performed by fitting the point spread function of the photoluminescent spots corresponding to UCNP location by the Gaussian function, and calculation of mean square displacement. Results. UCNPs were rapidly internalized by SK-BR-3 cells and retained in the cells for at least 12 h. Two types of the particles motion were registered: (i) isotropic random spatial fluctuations with relatively small amplitudes and low rate of displacement, and (ii) flick and directional movements with rates up to 1.2 µm/s and total displacement up to tens of microns. The registered types of motion can be attributed to diffusion in local area and intracellular transport of nanoparticles encapsulated in vesicles, respectively. Conclusion. The demonstrated tracking of UCNPs in human breast adenocarcinoma cells showed that Yb3+ , Tm3+ doped NaYF4 nanoparticles are an advanced agent for dynamic studies of intracellular processes. The implemented scheme for UCNPs tracking provides long-term observation with preservation of cell viability for at least several hours. In total, almost complete absence of cell autofluorescence and UCNPs photobleaching, low invasiveness, fast rate of image acquisition allow us to consider the proposed approach as useful for a variety of tasks in biomedical research.

© 2018, The Author(s). Studies on the methods of nanoparticle (NP) synthesis, analysis of their characteristics, and exploration of new fields of their applications are at the forefront of modern nanotechnology. The possibility of engineering water-soluble NPs has paved the way to their use in various basic and applied biomedical researches. At present, NPs are used in diagnosis for imaging of numerous molecular markers of genetic and autoimmune diseases, malignant tumors, and many other disorders. NPs are also used for targeted delivery of drugs to tissues and organs, with controllable parameters of drug release and accumulation. In addition, there are examples of the use of NPs as active components, e.g., photosensitizers in photodynamic therapy and in hyperthermic tumor destruction through NP incorporation and heating. However, a high toxicity of NPs for living organisms is a strong limiting factor that hinders their use in vivo. Current studies on toxic effects of NPs aimed at identifying the targets and mechanisms of their harmful effects are carried out in cell culture models; studies on the patterns of NP transport, accumulation, degradation, and elimination, in animal models. This review systematizes and summarizes available data on how the mechanisms of NP toxicity for living systems are related to their physical and chemical properties.

© 2018 Russian Electronic Journal of Radiology.All Rights Reserved. agnetic iron oxide nanoparticles (MNP) show great potential as the contrast agent for magnetic resonance imaging (MRI). Purpose. To evaluate the efficiency and safety of the contrast agent based on HSA-coated MNP on the model of the C6 glioma. Materials and methods. Extensive preclinical research of specific activity has been performed. Studies were conducted on the model of the orthotopic C6 glioma. Results. In the preclinical studies, it was demonstrated that HSA-coated magnetic iron oxide nanoparticles (MNP-HSA) accumulate in the tumor and its large vessels. Conclusion. Magnetic resonance imaging with contrast agent allows visualization of the tumor tissue and its vascularization.

Studies on the methods of nanoparticle (NP) synthesis, analysis of their characteristics, and exploration of new fields of their applications are at the forefront of modern nanotechnology. The possibility of engineering water-soluble NPs has paved the way to their use in various basic and applied biomedical researches. At present, NPs are used in diagnosis for imaging of numerous molecular markers of genetic and autoimmune diseases, malignant tumors, and many other disorders. NPs are also used for targeted delivery of drugs to tissues and organs, with controllable parameters of drug release and accumulation. In addition, there are examples of the use of NPs as active components, e.g., photosensitizers in photodynamic therapy and in hyperthermic tumor destruction through NP incorporation and heating. However, a high toxicity of NPs for living organisms is a strong limiting factor that hinders their use in vivo. Current studies on toxic effects of NPs aimed at identifying the targets and mechanisms of their harmful effects are carried out in cell culture models; studies on the patterns of NP transport, accumulation, degradation, and elimination, in animal models. This review systematizes and summarizes available data on how the mechanisms of NP toxicity for living systems are related to their physical and chemical properties.

Studies on the methods of nanoparticle (NP) synthesis, analysis of their characteristics, and exploration of new fields of their applications are at the forefront of modern nanotechnology. The possibility of engineering water-soluble NPs has paved the way to their use in various basic and applied biomedical researches. At present, NPs are used in diagnosis for imaging of numerous molecular markers of genetic and autoimmune diseases, malignant tumors, and many other disorders. NPs are also used for targeted delivery of drugs to tissues and organs, with controllable parameters of drug release and accumulation. In addition, there are examples of the use of NPs as active components, e.g., photosensitizers in photodynamic therapy and in hyperthermic tumor destruction through NP incorporation and heating. However, a high toxicity of NPs for living organisms is a strong limiting factor that hinders their use in vivo. Current studies on toxic effects of NPs aimed at identifying the targets and mechanisms of their harmful effects are carried out in cell culture models; studies on the patterns of NP transport, accumulation, degradation, and elimination, in animal models. This review systematizes and summarizes available data on how the mechanisms of NP toxicity for living systems are related to their physical and chemical properties.