Персона: Тимошенко, Виктор Юрьевич
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Инженерно-физический институт биомедицины
Цель ИФИБ и стратегия развития – это подготовка высококвалифицированных кадров на базе передовых исследований и разработок новых перспективных методов и материалов в области инженерно-физической биомедицины. Занятие лидерских позиций в биомедицинских технологиях XXI века и внедрение их в образовательный процесс, что отвечает решению практикоориентированной задачи мирового уровня – диагностике и терапии на клеточном уровне социально-значимых заболеваний человека.
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Виктор Юрьевич
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- ПубликацияТолько метаданныеInteraction of SiFe Nanoparticles with Epithelial and Lymphoid Cells(2020) Sharonova, N. V.; Svirshchevskaya, E. V.; Popov, A. A.; Karpov, N. V.; Tikhonovsky, G. V.; Zakharkiv, A. Y.; Timoshenko, V. Y.; Klimentov, S. M.; Oleinikov, V. A.; Попов, Антон Александрович; Тихоновский, Глеб Валерьевич; Захаркив, Анастасия Юрьевна; Тимошенко, Виктор Юрьевич; Климентов, Сергей Михайлович; Олейников, Владимир АлександровичSilicon and silicon-based nanoparticles (SiNP) attract scientific attention due to the biocompatibility and assimilation of silicon by body tissues. Iron-doped SiNP (SiFeNP) allow the use of ferromagnetic properties of iron for NP detection and the possibility of therapeutic application of SiFeNP. The purpose of this work was to analyze the interaction of SiFeNP with epithelial cells (EC) COLO357 and SW620 and human peripheral blood lymphocytes (PBL). SiFeNP were obtained by laser ablation and divided into the NP1 and NP2 fractions of 100 and 150 nm size, respectively. Cytotoxicity, apoptosis induction, reactive oxygen species (ROS) production, and lysosome metabolism were analyzed using in vitro methods. EC were found to efficiently incytosed both types of NPs, which resulted in the increase in the granularity of cells. NP did not cause apoptosis or EC necrosis, but accumulated in lysosomes, which led to a decrease in the membrane potential of lysosomes. In turn, a decrease in the level of EC metabolism led to a gradual (24 h) increase in ROS production by 10-15%. NP1 caused more ROS than NP2, and accumulated more in the EC, which may be the result of a difference in the particle size. SiFeNP did not interact with PBL. Thus, the total cytotoxicity of SiFeNP did not exceed 20%, which is associated with a decrease in lysosome metabolism and insignificant ROS production.
- ПубликацияТолько метаданныеVibrational Analysis of Silicon Nanoparticles Using Simulation and Decomposition of Raman Spectra(2020) Povarnitsyn, M. E.; Shcheblanov, N. S.; Ivanov, D. S.; Timoshenko, V. Y.; Klimentov, S. M.; Тимошенко, Виктор Юрьевич; Климентов, Сергей МихайловичWe report a classical molecular-dynamics simulation of models of silicon nanoparticles and bulk sili-con, in both the crystalline and the amorphous phase, to investigate their vibrational properties. By using a dynamical-matrix approach and a bond-polarizability model, together with a Raman-decomposition approach [Phys. Rev. B 100, 134309 (2019)], we present a comprehensive analysis of the vibrational spec-tra. In particular, the dependence of the high-frequency range of the Raman spectra on the nanoparticle size is studied. The results are in good agreement with Raman measurements on crystalline nanoparticles and explain the role of the nanoparticle surface, which is responsible for a shift in the Raman spectrum dependent on the particle size. In the low-frequency range, our Raman calculations reproduce well the Lamb-mode signatures, which obey the selection rules deduced by Duval [Phys. Rev. B 46, 5795 (1992)]. As a result of systematic Raman modeling, we confirm the scaling of the main signatures (ascribed to the Lamb modes with l = 0, 2) with respect to the nanoparticle size. By using the Raman-decomposition approach, we demonstrate that only a thin surface layer several angstroms in thickness contributes to the low-frequency Raman signature regardless of the nanoparticle size in the case of both the amorphous and the crystalline phase. Finally, we study the role of the coordination number of the atoms in the surface layer of a nanoparticle in order to explain the difference between the crystalline and amorphous vibrational spectra. The approach developed provides knowledge necessary for the correct interpretation of Raman spectra of nanoparticles, which opens up the possibility of quantitative control of surface-induced effects that may be relevant to various applications.
- ПубликацияТолько метаданныеMorphology and photoluminescence properties of silicon nanoparticles deposited in helium-nitrogen mixtures maintained at low residual pressures(2021) Fronya, A. A.; Antonenko, S. V.; Derzhavin, S. I.; Karpov, N. V.; Kharin, A. Yu.; Garmash, A. A.; Kargin, N. I.; Klimentov, S. M.; Timoshenko, V. Yu.; Kabashin, A. V.; Фроня, Анастасия Андреевна; Антоненко, Сергей Васильевич; Гармаш, Александр Александрович; Каргин, Николай Иванович; Климентов, Сергей Михайлович; Тимошенко, Виктор Юрьевич; Кабашин, Андрей ВикторовичWe elaborated a technique of pulsed laser ablation in gas mixtures (He-N2), maintained under residual pressures of 0.5-5 Torr to deposit silicon (Si)-based nanostructured films on a substrate. We show that the deposited films can exhibit strong photoluminescence (PL) emission with the position of peaks depending on the pressure of ambient gas and the ratio of gases in the mixture. Nanostructured films prepared in pure He gas exhibited a strong band in the infrared range (around 760 nm) and a weak band in the green range (550 nm), which were attributed to quantum-confined excitonic states in small Si nanocrystals and radiative transitions via the localized electronic states in silicon suboxide coating, respectively. In contrast, nanostructured films prepared in He-N2 mixtures exhibited more intense “green-yellow” PL band centered at 580 nm, which was attributed to a radiative recombination in amorphous oxynitride (a-SiNxOy) coating of Si nanocrystals. We also present a detailed analysis of morphology of nanostructures Si-based films prepared by laser ablation. Finally, we show that the nanocrystals can be removed from the substrate and milled by ultrasound to form aqueous solutions of colloidal Si nanopartiles. The fabricated Si-based nanocrystals present a promising object for theranostics, combining imaging functionality based on PL emission and a series of therapy functionalities (photo and radiofrequency hyperthermia, photodynamic therapy). © 2021 Institute of Physics Publishing. All rights reserved.
- ПубликацияТолько метаданныеGermanium Nanoparticles Prepared by Laser Ablation in Low Pressure Helium and Nitrogen Atmosphere for Biophotonic Applications(2022) Fronya, A. A.; Antonenko, S. V.; Karpov, N. V.; Pokryshkin, N. S.; Eremina, A. S.; Kharin, A. Y.; Dombrovska, Y. I.; Garmash, A. A.; Kargin, N. I.; Klimentov, S. M.; Timoshenko, V. Y.; Фроня, Анастасия Андреевна; Антоненко, Сергей Васильевич; Еремина, Анна Сергеевна; Гармаш, Александр Александрович; Каргин, Николай Иванович; Климентов, Сергей Михайлович; Тимошенко, Виктор ЮрьевичDue to particular physico-chemical characteristics and prominent optical properties, nanostructured germanium (Ge) appears as a promising material for biomedical applications, but its use in biological systems has been limited so far due to the difficulty of preparation of Ge nanostructures in a pure, uncontaminated state. Here, we explored the fabrication of Ge nanoparticles (NPs) using methods of pulsed laser ablation in ambient gas (He or He-N2 mixtures) maintained at low residual pressures (1-5 Torr). We show that the ablated material can be deposited on a substrate (silicon wafer in our case) to form a nanostructured thin film, which can then be ground in ethanol by ultrasound to form a stable suspension of Ge NPs. It was found that these formed NPs have a wide size dispersion, with sizes between a few nm and hundreds of nm, while a subsequent centrifugation step renders possible the selection of one or another NP size fraction. Structural characterization of NPs showed that they are composed of aggregations of Ge crystals, covered by an oxide shell. Solutions of the prepared NPs exhibited largely dominating photoluminescence (PL) around 450 nm, attributed to defects in the germanium oxide shell, while a separated fraction of relatively small (5-10 nm) NPs exhibited a red-shifted PL band around 725 nm under 633 nm excitation, which could be attributed to quantum confinement effects. It was also found that the formed NPs exhibit high absorption in the visible and near-IR spectral ranges and can be strongly heated under photoexcitation in the region of relative tissue transparency, which opens access to phototherapy functionality. Combining imaging and therapy functionalities in the biological transparency window, laser-synthesized Ge NPs present a novel promising object for cancer theranostics.
- ПубликацияТолько метаданныеInternational symposium and international school for young scientists on "physics, engineering and technologies for biomedicine"(2021) Kabashin, A. V.; Klimentov, S. M.; Timoshenko, V. Yu.; Fronya, A. A.; Кабашин, Андрей Викторович; Климентов, Сергей Михайлович; Тимошенко, Виктор Юрьевич; Фроня, Анастасия АндреевнаAbstract International Symposium and International School for Young Scientists on “Physics, Engineering and Technologies for Biomedicine” (PhysBioSymp) is an annually held event in National Research Nuclear University MEPhI (https://eng.mephi.ru/) (Moscow, Russia) since 2016. This symposium is conceived as the main conference of the Institute of Engineering Physics for Biomedicine (PhysBio, https://physbio.mephi.ru/), which is one of new strategic academic units founded in 2016 in the course of transformation of MEPhI from the technical to a global university in order to extend its portfolio toward life sciences, chemical and biomedical engineering. Following the chosen strategy, PhysBio aims at the advancement of its international reputation in biomedical sciences and technologies, as well as the integration of latest research achievements into the educational process in order to contribute to the solution of global problems, such as early diagnostics and efficient therapy of socially significant diseases, including cancer. Conceived as an essentially interdisciplinary institution, PhysBio is unique in combining powerful background of MEPhI in physics, mathematics, engineering, material sciences, nanotechnologies and expertise in new areas in chemistry and biology in order to develop breakthrough technologies for biomedical applications. List of Committees are available in this pdf.
- ПубликацияТолько метаданныеPhotoluminescent Si-based nanocrystals prepared by pulsed laser ablation in low-pressure helium-nitrogen mixtures for biomedical applications(2020) Kharin, A. Y.; Fronya, A. A.; Antonenko, S. V.; Karpov, N. V.; Derzhavin, S. I.; Dombrovska, Y. I.; Garmash, A. A.; Kargin, N. I.; Klimentov, S. M.; Timoshenko, V. Y.; Kabashin, A. V.; Фроня, Анастасия Андреевна; Антоненко, Сергей Васильевич; Гармаш, Александр Александрович; Каргин, Николай Иванович; Климентов, Сергей Михайлович; Тимошенко, Виктор Юрьевич; Кабашин, Андрей Викторович© 2020 SPIE.Nanocrystalline silicon (Si) films were synthesized by nanosecond laser ablation of crystalline Si targets in low-pressure helium (He) and nitrogen (N2) gas mixtures. Photoluminescence (PL) spectra of the prepared samples were found to depend on the He/N2 ratio in the gas mixture. The ablation pure He atmosphere allowed us to prepare Si nanocrystals (NCs) exhibiting a PL band in red-near-IR range, while samples prepared in the presence of N2 exhibited a strong PL band with maximum in the green-yellow region. Such a modification of PL properties can be explained by the presence of amorphous Si oxynitride (a-SiNxOy) on the surface of Si-NCs. Structural studies of the prepared samples by means of the scanning electron microscopy revealed different morphology for Si-NCs produced under different gas mixtures. After treating of the films by ultrasound and dispersing in water, Si-NCs can be used as novel biodegradable markers for bioimaging, while the observed spectral tailoring effect makes possible an adjustment of the PL emission of such markers to a concrete bioimaging task.