Antiviral efficacy of nanomaterial-treated textiles in real-life like exposure conditions

We thank the following people and institutions for their contribution to our investigation. Toomas Varjund from TAD Logistics OÜ for providing the textiles. Ülis Sõukand from Estonian Environmental Research Center for his help with methods of chemical analysis. Estonian Research Council projects COVSG2, PRG629, PRG1496, PRG1154 and European Commission project STOP (Grant agreement ID: 101057961) for their financial support. The Center of nanomaterials technologies and research (NAMUR+) for core facility funded by project TT13 which was used conducting the research.Due to the growing interest towards reducing the number of potentially infectious agents on critical high-touch surfaces, the popularity of antimicrobially and antivirally active surfaces, including textiles, has increased. The goal of this study was to create antiviral textiles by spray-depositing three different nanomaterials, two types of CeO2 nanoparticles and quaternary ammonium surfactant CTAB loaded SiO2 nanocontainers, onto the surface of a knitted polyester textile and assess their antiviral activity against two coronaviruses, porcine transmissible gastroenteritis virus (TGEV) and severe acute respiratory syndrome virus (SARS CoV-2). Antiviral testing was carried out in small droplets in semi-dry conditions and in the presence of organic soiling, to mimic aerosol deposition of viruses onto the textiles. In such conditions, SARS CoV-2 stayed infectious at least for 24 h and TGEV infected cells even after 72h of semi-dry deposition suggesting that textiles exhibiting sufficient antiviral activity before or at 24 h, can be considered promising. The antiviral efficacy of nanomaterial-deposited textiles was compared with the activity of the same nanomaterials in colloidal form and with positive control textiles loaded with copper nitrate and CTAB. Our results indicated that after deposition onto the textile, CeO2 nanoparticles lost most of their antiviral activity, but antiviral efficacy of CTAB-loaded SiO2 nanocontainers was retained also after deposition. Copper nitrate deposited textile that was used as a positive control, showed relatively high antiviral activity as expected. However, as copper was effectively washed away from the textile already during 1 h, the use of copper for creating antiviral textiles would be impractical. In summary, our results indicated that antiviral activity of textiles cannot be predicted from antiviral efficacy of the deposited compounds in colloid and attention should be paid on prolonged efficacy of antivirally coated textiles.--//-- Alexandra Nefedova, Kai Rausalu, Eva Zusinaite, Vambola Kisand, Mati Kook, Krisjanis Smits, Alexander Vanetsev, Angela Ivask, Antiviral efficacy of nanomaterial-treated textiles in real-life like exposure conditions, Heliyon, Volume 9, Issue 9, 2023, e20067, ISSN 2405-8440, https://doi.org/10.1016/j.heliyon.2023.e20067. Published under the CC BY-NC-ND licence.Estonian Research Council projects COVSG2, PRG629, PRG1496, PRG1154; European Commission project STOP (Grant agreement ID: 101057961); the Institute of Solid State Physics, University of Latvia has received funding from EU CAMART2 project (European Union's Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017 TeamingPhase2 under grant agreement No. 739508

Ultrafast hybrid nanocomposite scintillators: A review

In recent years, demand for scintillation detectors with high time resolution (better than 100 ps) has emerged in high-energy physics and medical imaging applications. In particular, time of flight positron emission tomography (TOF-PET) can greatly benefit from increasing time resolution of scintillators, which leads to the increase of signal-to-noise ratio, decrease of patient dose, and achievement of the superior spatial resolution of PET images. Currently, extensive research of various types of materials is carried out to achieve the best time resolution. In this review, the recent progress of various approaches is summarized and scintillation compounds with the best temporal characteristics are first reviewed. The review presents the physical processes causing fast luminescence in inorganic and organic materials. Special attention is paid to nanocomposites which belong to a new perspective class of scintillating materials, consisting of a plastic matrix, inorganic nanocrystalline fillers, and organic or inorganic luminescence activators and shifters. The main features and functions of all parts of existing and prospective nanocomposite scintillators are also discussed. A number of currently created and investigated nanocomposite materials with various compounds and structures are reviewed. © 2021 Elsevier B.V.Eesti Teadusagentuur, ETAg: PRG111, PRG629; European Regional Development Fund, ERDF: 2014-2020.4.01.15–0011, TK141Authors thank Minobrnauki project FEUZ-2020-0059 and Estonian Research Council (grants PRG629 and PRG111 ) for financial support. Authors are also grateful for partial support from the European Regional Development Fund (DoRA Pluss program) and the ERDF funding in Estonia granted to the Center of Excellence TK141 “ Advanced materials and high-technology devices for sustainable energetics, sensorics and nanoelectronics ” (project No. 2014-2020.4.01.15–0011 )

Antiviral efficacy of cerium oxide nanoparticles

The authors gratefully acknowledge the financial support by the Estonian Research Council Grants (COVSG2, PRG629, PRG1496), Estonian Centre of Excellence in Research project “Advanced materials and high-technology devices for sustainable energetics, sensorics and nanoelectronics” TK141 (2014-2020.4.01.15-0011) and University of Tartu Development Fund (PLTFYARENG53). The research was partly conducted using the NAMUR+ core facility funded by projects “Center of nanomaterials technologies and research” (2014-2020.4.01.16-0123) and TT13.Nanomaterials are prospective candidates for the elimination of viruses due to their multimodal mechanisms of action. Here, we tested the antiviral potential of a largely unexplored nanoparticle of cerium dioxide (CeO2). Two nano-CeO2 with opposing surface charge, (+) and (−), were assessed for their capability to decrease the plaque forming units (PFU) of four enveloped and two non-enveloped viruses during 1-h exposure. Statistically significant antiviral activity towards enveloped coronavirus SARS-CoV-2 and influenza virus was registered already at 20 mg Ce/l. For other two enveloped viruses, transmissible gastroenteritis virus and bacteriophage φ6, antiviral activity was evidenced at 200 mg Ce/l. As expected, the sensitivity of non-enveloped viruses towards nano-CeO2 was significantly lower. EMCV picornavirus showed no decrease in PFU until the highest tested concentration, 2000 mg Ce/l and MS2 bacteriophage showed slight non-monotonic response to high concentrations of nano-CeO2(−). Parallel testing of antiviral activity of Ce3+ ions and SiO2 nanoparticles allows to conclude that nano-CeO2 activity was neither due to released Ce-ions nor nonspecific effects of nanoparticulates. Moreover, we evidenced higher antiviral efficacy of nano-CeO2 compared with Ag nanoparticles. This result along with low antibacterial activity and non-existent cytotoxicity of nano-CeO2 allow us to propose CeO2 nanoparticles for specific antiviral applications. © 2022, The Author(s). --//-- This is an open access article Nefedova A, Rausalu K, Zusinaite E, Vanetsev A, Rosenberg M, Koppel K, Lilla S, Visnapuu M, Smits K, Kisand V, Tätte T, Ivask A., "Antiviral efficacy of cerium oxide nanoparticles", Scientific Reports (2022); 12(1):18746, doi: 10.1038/s41598-022-23465-6 published under the CC BY 4.0 licence.Estonian Research Council Grants (COVSG2, PRG629, PRG1496); Estonian Centre of Excellence in Research TK141 (2014-2020.4.01.15-0011); University of Tartu Development Fund (PLTFYARENG53); Institute of Solid-State Physics, University of Latvia has received funding from the European Union's Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-Teaming Phase 2 under grant agreement No. 739508, project CAMART2

Visualization of Nd3+-doped Laf3 Nanoparticles For Near Infrared Bioimaging via Upconversion Luminescence at Multiphoton Excitation Microscopyvisualization of Nd3+-doped Laf3 Nanoparticles For Near Infrared Bioimaging via Upconversion Luminescence at Multiphoton Excitation Microscopy

Recent developments in the field of biophotonics facilitate the raise of interest to inorganic nanoparticles (NPs) doped with Nd 3+ ions, because of their near-infrared (NIR) absorption. These NPs are interesting bioimaging probes for deep tissue visualization, while they can also act as local thermometers in biological tissues. Despite the good possibilities for visualization of NPs with Nd 3+ ions in NIR spectral range, difficulties arise when studying the cellular uptake of these NPs using commercially available fluorescence microscopy systems, since the selection of suitable luminescence detectors is limited. However, Nd 3+ ions are able to convert NIR radiation into visible light, showing upconversion properties. In this paper we found optimal parameters to excite upconversion luminescence of Nd 3+ :LaF 3 NPs in living cells and to compare the distribution of the NPs inside the cell culture of human macrophages THP-1 obtained by two methods. Firstly, by detecting the upconversion luminescence of the NPs in VIS under NIR multiphoton excitation using laser scanning confocal microscopy and secondly, using transmission electron microscopy

Optomagnetic Nanoplatforms for In Situ Controlled Hyperthermia

This is the peer reviewed version of the following article: Ortgies, Dirk H., Teran, Francisco J. Rocha, Uéslen, Cueva, Leonar de la, Salas, Gorka, cabrera, David, Vanetsev, Alexander S., Rähn, Mikhel, Väino,Sammelselg, Orlosvkii, Yurii V. and Jaque, Daneil "Optomagnetic nanoplatforms for in situ controlled hyperthermia" Advances Funtcional Materials 28.11 (2018) which has been published in final form at http://doi.org/10.1002/adfm.201704434. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving."Magnetic nanoparticles (M:NPs) are unique agents for in vivo thermal therapies due to their multimodal capacity for efficient heat generation under optical and/or magnetic excitation. Nevertheless, their transfer from laboratory to the clinic is hampered by the absence of thermal feedback and by the influence that external conditions (e.g., agglomeration and biological matrix interactions) have on their heating efficiency. Overcoming these limitations requires, first, the implementation of strategies providing thermal sensing to M:NPs in order to obtain in situ thermal feedback during thermal therapies. At the same time, M:NPs should be modified so that their heating efficiency will be maintained independently of the environment and the added capability for thermometry. In this work, optomagnetic hybrid nanostructures (OMHSs) that simultaneously satisfy these two conditions are presented. Polymeric encapsulation of M:NPs with neodymium-doped nanoparticles results in a hybrid structure capable of subtissue thermal feedback while making the heating efficiency of M:NPs independent of the medium. The potential application of the OMHSs herein developed for fully controlled thermal therapies is demonstrated by an ex vivo endoscope-assisted controlled intracoronary heating experimentThis work was supported by the Spanish Ministry of Economy and Competitiveness under Projects # MAT2016-75362-C3-1-R, # MAT2015-71806-R and # MAT2013-47395-C4-3-R, the Comunidad de Madrid (NANOFRONTMAG-CM, S2013/MIT-2850), and through the Instituto de Salud Carlos III under Project # PI16/00812. This work has also received funding from European Union’s H2020 and FP7 programme (NOCANTHER, GA 685795). D.H.O. is grateful to the Spanish Ministry of Economy and Competitiveness for a Juan de la Cierva scholarship (FJCI-2014-21101) and F.J.T. for a Ramon y Cajal fellowship (RYC-2011-09617). COST Actions CM1403 and TD1402 (RADIOMAG) are also acknowledged. The synthesis and preliminary testing of the fluorescence properties of the LaF3:Nd(3%) NPs was supported by Project # 16-12-10077 of the Russian Science Foundation. Nonfluorescent characterization of the OMHSs was supported by projects IUT2-24 and IUT20-54 of the Estonian Ministry of Education and Researc

Modern microwave methods in solid state inorganic materials chemistry: from fundamentals to manufacturing

No abstract available

ВИЗУАЛИЗАЦИЯ НАНОЧАСТИЦ LaF3, ДОПИРОВАННЫХ Nd3+, ДЛЯ БИОИМИДЖИНГА В БЛИЖНЕМ ИНФРАКРАСНОМ ДИАПАЗОНЕ ПО АП-КОНВЕРСИОННОЙ ЛЮМИНЕСЦЕНЦИИ ПРИ МИКРОСКОПИИ С МУЛЬТИФОТОННЫМ ВОЗБУЖДЕНИЕМ

Recent developments in the field of biophotonics facilitate the raise of interest to inorganic nanoparticles (NPs) doped with Nd3+ ions, because of their near-infrared (NIR) absorption. These NPs are interesting bioimaging probes for deep tissue visualization, while they can also act as local thermometers in biological tissues. Despite the good possibilities for visualization of NPs with Nd3+ ions in NIR spectral range, difficulties arise when studying the cellular uptake of these NPs using commercially available fluorescence microscopy systems, since the selection of suitable luminescence detectors is limited. However, Nd3+ ions are able to convert NIR radiation into visible light, showing upconversion properties. In this paper we found optimal parameters to excite upconversion luminescence of Nd3++:LaF NPs in living cells and to compare the distribution of the NPs inside the cell culture of human macrophages THP-1 obtained by two methods. Firstly, by detecting the upconversion luminescence of the NPs inVIS under NIR multiphoton excitation using laser scanning confocal microscopy and secondly, using transmission electron microscopy.Последние разработки в области биофотоники способствуют повышению интереса к неорганическим наночастицам (НЧ), допированным ионами Nd3+, из-за их поглощения в ближнем инфракрасном (БИК) спектральном диапазоне. Эти НЧ являются перспективными зондами для глубокой визуализации тканей, в то же время они могут служить локальными термометрами в биологических тканях. Несмотря на хорошие возможности визуализации НЧ с ионами Nd3+ в БИК спектральном диапазоне, при изучении внутриклеточного распределения этих НЧ с использованием коммерчески доступных флуоресцентных микроскопических систем возникают трудности из-за ограниченности выбора подходящих детекторов люминесценции. Однако, ионы Nd3+ способны преобразовывать БИК излучение в видимый свет, демонстрируя ап-конверсионные свойства. В этой работе мы определили оптимальные параметры для возбуждения ап-конверсионной люминесценции НЧ Nd3+: LaF в живых клетках и сравнили распределение НЧ внутри клеток культуры человеческих макрофагов THP-1, полученное двумя методами. Во-первых, путем регистрации ап-конверсионной люминесценции НЧ в видимом диапазоне при многофотонном возбуждении в БИК диапазоне спектра с использованием лазерной сканирующей конфокальной микроскопии и, во-вторых, с использованием просвечивающей электронной микроскопии

НЕИНВАЗИВНАЯ ОЦЕНКА ЛОКАЛЬНОЙ ТЕМПЕРАТУРЫ НАГРЕВА БИОТКАНЕЙ ПОД ДЕЙСТВИЕМ ЛАЗЕРНОГО ИЗЛУЧЕНИЯ ПО СПЕКТРАМ ЛЮМИНЕСЦЕНЦИИ ИОНОВ Nd3+

Laser hyperthermia is one of the promising methods for treatment of oncological diseases. For routine clinical use of hyperthermia, it is necessary to control the uniformity and localization of heat within the tumor. Local heating can be achieved by using special thermal agents, such as nanoparticles doped with rare-earth ions. Measurement of the temperature of the thermal agents will allow timely regulation of the applied laser radiation excitation power and optimization of the hyperthermia process.The paper presents the results of a study on the non-invasive determination of the YPO4 nanoparticles doped with Nd3+ temperature with sensitivity of 0.2% °С-1 in 30-60°С temperature range. The temperature of the nanoparticles was calculated from the Nd3+ luminescence spectra in the 800-1000 nm range under excitation into 4F5/2 energy state by 805 nm laser. A calibration procedure for recalculating the ratio of the luminescence intensities from the Stark sublevels of the 4F3/2 Nd3+ state into the values of the real NP temperature in accordance with the Boltzmann distribution is given. An algorithm for calculating luminescence intensities for individual Stark components is proposed. After calculating the intensities corresponding to each individual Stark component, all the intensities related to the transition from the upper and lower Stark sublevels of the 4F3/2 state are summed, and then their ratio is calculated. The resulting ratio is normalized to the value of the ratio at room temperature and, in accordance with the calibration dependence, is recalculated into the NP heating temperature. It was demonstrated that the investigated 1%Nd3+:YPO4 nanoparticles can be used as "primary” thermometers that do not require additional recalibration to evaluate the temperature in the range used for hyperthermia.Одним из перспективных методов лечения онкологических заболеваний является метод лазерной гипертермии. Для рутинного клинического использования гипертермии необходимо контролировать однородность и локальность нагрева внутри опухоли. Добиться локального нагрева можно при использовании специальных термоагентов, в качестве которых могут выступать наночастицы (НЧ), допированные редкоземельными ионами. Измерение температуры термоагентов в режиме реального времени позволит своевременно регулировать подаваемую возбуждающую мощность лазерного излучения и оптимизировать режимы гипертермии.В работе представлены результаты исследования по неинвазивному определению температуры НЧ YPO4, допированных ионами Nd3+, c чувствительностью 0,2% °С-1 в диапазоне температур 30-60°С. Температура НЧ рассчитывалась по спектрам люминесценции Nd3+ в диапазоне 800-1000 нм при возбуждении на уровень 4F5/2 лазерным излучением 805 нм. Приведена процедура калибровки для пересчета отношения интенсивностей люминесценции со штарковских подуровней состояния 4F3/2 Nd3+ в значения реальной температуры НЧ в соответствии с распределением Больцмана. Предложен алгоритм расчета интенсивностей люминесценции для отдельных штарковских компонент. После вычисления интенсивностей, соответствующих каждой отдельной штарковской компоненте, происходит суммирование всех интенсивностей, относящихся к переходу с верхнего и с нижнего штарковских подуровней состояния 4F3/2, а затем вычисляется их отношение. Полученное отношение нормируется на значение отношения при комнатной температуре и в соответствии с калибровочной зависимостью пересчитывается в температуру нагрева НЧ. Продемонстрировано, что исследуемые НЧ Nd3+:YPO4 могут быть использованы в качестве так называемых «первичных» термометров, не требующих дополнительной перекалибровки для оценки температуры в диапазоне температур, используемом при гипертермии

Rheological Properties of MWCNT-Doped Titanium-Oxo-Alkoxide Gel Materials for Fiber Drawing

A strategy of doping by multi-walled carbon nanotubes (MWCNT) to enhance mechanical strength and the electrical conductivity of ceramic fibers has nowadays attracted a great deal of attention for a wide variety of industrial applications. This study focuses on the effect of MWCNTs on rheological properties of metal alkoxide precursors used for the preparation of nanoceramic metal oxide fibers. The rheological behavior of MWCNT-loaded titanium alkoxide sol precursors has been evaluated via an extensional rheometry method. A substantial decrease in elongational viscosity and relaxation time has been observed upon an introduction of MWCNTs even of low concentrations (less than 0.1 wt.%). A high quality MWCNT/nanoceramic TiO2 composite fibers drawn from the specified precursors has been validated. The MWCNT percolation, which is mandatory for electrical conductivity (50 S/m), has been achieved at 1 wt.% MWCNT doping