Microglia form satellites with different neuronal subtypes in the adult murine central nervous system

Microglia are the innate immune cells of the central nervous system (CNS). In the adult uncompromised CNS, they have a highly ramified morphology and continuously extend and retract their processes. A subpopulation of microglial cells forms close soma-to-soma contacts with neurons and have been termed satellite microglia, yet the role of such interaction is largely unknown. Here, we analyzed the distribution of satellite microglia in different areas of the CNS of adult male mice applying transgenic- and immunolabeling of neuronal subtypes and microglia followed by three-dimensional imaging analysis. We quantified satellite microglia associated with GABAergic and glutamatergic neurons in the somatosensory cortex, striatum, and thalamus; with dopaminergic and serotonergic neurons in the basal forebrain and raphe nucleus, respectively; and with cerebellar Purkinje cell neurons. Satellite microglia in the retina were assessed qualitatively. Microglia form satellites with all neuronal subtypes studied, whereas a preference for a specific neuron subtype was not found. The occurrence and frequency of satellite microglia is determined by the histo-architectural organization of the brain area and the densities of neuronal somata therein

Synthesis and Characterization of Electro-Explosive Magnetic Nanoparticles for Biomedical Applications

Nowadays there are new magnetic nanostructures based on bioactive metals with low toxicity and high efficiency for a wide range of biomedical applications including drugs delivery, antimicrobial drugs design, cells' separation and contrasting. For such applications it is necessary to develop highly magnetic particles with less than100 nm in size. In the present study magnetic nanoparticles Fe, Fe[3]O[4] and bimetallic Cu/Fe with the average size of 60- 90 nm have been synthesized by electrical explosion of wire in an oxygen or argon atmosphere. The produced nanoparticles have been characterized with transmission electron microscopy, X-ray phase analysis, and nitrogen thermal desorption. The synthesized particles have shown antibacterial activity to gram-positive (S. aureus, MRSA) and gramnegative (E. coli, P. aeruginosa) bacteria. According to the cytological data Fe, Fe[3]O[4]and Cu/Fe nanoparticles have effectively inhibited viability of cancer cell lines Neuro-2a and J774. The obtained nanoparticles are promising for new antimicrobial drugs and antitumor agents' developmen

Synthesis and Characterization of Electro-Explosive Magnetic Nanoparticles for Biomedical Applications

Nowadays there are new magnetic nanostructures based on bioactive metals with low toxicity and high efficiency for a wide range of biomedical applications including drugs delivery, antimicrobial drugs design, cells' separation and contrasting. For such applications it is necessary to develop highly magnetic particles with less than100 nm in size. In the present study magnetic nanoparticles Fe, Fe[3]O[4] and bimetallic Cu/Fe with the average size of 60- 90 nm have been synthesized by electrical explosion of wire in an oxygen or argon atmosphere. The produced nanoparticles have been characterized with transmission electron microscopy, X-ray phase analysis, and nitrogen thermal desorption. The synthesized particles have shown antibacterial activity to gram-positive (S. aureus, MRSA) and gramnegative (E. coli, P. aeruginosa) bacteria. According to the cytological data Fe, Fe[3]O[4]and Cu/Fe nanoparticles have effectively inhibited viability of cancer cell lines Neuro-2a and J774. The obtained nanoparticles are promising for new antimicrobial drugs and antitumor agents' developmen

Preparation of nano/micro bimodal aluminum powder by electrical explosion of wires

Electrical explosion of aluminum wires has been shown to be a versatile method for the preparation of bimodal nano/micro powders. The energy input into the wire has been found to determine the relative content of fine and coarse particles in bimodal aluminum powders. The use of aluminum bimodal powders has been shown to be promising for the development of high flowability feedstocks for metal injection molding and material extrusion additive manufacturing

Investigation of the peculiarities of oxidation of Ti/Al nanoparticles on heating to obtain TiO2/Al2O3 composite nanoparticles

The creation of new nanomaterials with improved characteristics, as well as the development of new approaches to obtain such materials is an urgent task in science and technology. One of the promising directions in obtaining improved nanomaterials is the use of precursors in the form of multicomponent metal nanoparticles. Thermal oxidation of bimetallic Ti/ Al nanoparticles obtained by electrical explosion of wires was investigated in this work. Ti/Al nanoparticles have been found to be completely oxidized with the formation of composite TiO2/ Al2O3 nanoparticles after calcination at 900 °C. The formation of TiO2 phase with a rutile structure on heating to 500 °C, and the formation of TiO2 phases with a rutile and anatase structure, as well as α-Al2O3 on heating to 700 °C have been established, in addition to the residue of unoxidized metals. Complete oxidation of Ti/Al nanoparticles occurs when heated to 900 °C. The photochemical activity of TiO2/ Al2O3 composite nanoparticles obtained at 900 °C was studied. The degradation of methyl orange dye reached 55% under UV irradiation for 120 min

Σ+ and ¯Σ− Polarization in the J/ψ and ψ(3686) Decays

From 1310.6×106  J/ψ and 448.1×106  ψ(3686) events collected with the BESIII experiment, we report the first observation of Σ+ and ¯Σ− spin polarization in e+e−→J/ψ[ψ(3686)]→Σ+¯Σ− decays. The relative phases of the form factors ΔΦ have been measured to be (−15.5±0.7±0.5)° and (21.7±4.0±0.8)° with J/ψ and ψ(3686) data, respectively. The nonzero value of ΔΦ allows for a direct and simultaneous measurement of the decay asymmetry parameters of Σ+→pπ0(α0=−0.998±0.037±0.009) and ¯Σ−→¯pπ0(¯α0=0.990±0.037±0.011), the latter value being determined for the first time. The average decay asymmetry, (α0−¯α0)/2, is calculated to be −0.994±0.004±0.002. The CP asymmetry ACP,Σ=(α0+¯α0)/(α0−¯α0)=−0.004±0.037±0.010 is extracted for the first time, and is found to be consistent with CP conservatio

Chemical behaviour of Al/Cu nanoparticles in water

Bimetallic Al/Cu nanoparticles with Al/Cu composition 10:90, 20:80, 40:60 were produced by method of simultaneous electrical explosion of metal pairs in the argon atmosphere. Nanopowders containing 20% and 40% (mass) of aluminum interacted with water at 40–70 °C and formed composite particles that were porous structures of nanopetal pseudoboehmite with nanosized copper-containing inclusions inside. Aluminum in nanopowder with Al/Cu composition 10:90 did not react with water, as far as it is in the phase of intermetallic compounds СuAl2 and Сu4Al9. Nanocomposite produced can be used as an active component of antibacterial agents

Бикомпонентные янус-наночастицы Zno-ag с высокой противоопухолевой активностью in vitro

Background. Nanoparticles (NPs) of zinc and silver oxide are promising antitumor agents, the use of which can enhance modern approaches to cancer treatment. Using bicomponent ZnO-Ag nanoparticles, one can increase the efficiency due to the occurrence of a synergistic antitumor effect. Among the main physicochemical properties that affect the antitumor activity of nanoparticles, one can distinguish their size and distribution of components inside the particle or their microstructure, however, these aspects are currently poorly understood.The aim of this study is the synthesis of ZnO-Ag nanoparticles using electrical explosive of wire technology and the in vitro study of the antitumor activity of NPs against breast ductal adenocarcinoma MCF-7 (ATCC HTB-22) and the HeLa cell line isolated from a cervical tumor.Material and Methods. ZnO-Ag nanoparticles were obtained by simultaneous electric explosion of zinc and silver twisted wires in a gas mixing atmosphere: argon and oxygen. The content of the components was regulated by varying the wire diameters. Physicochemical properties were studied using X-ray phase analysis, thermal desorption of nitrogen, and transmission electron microscopy. Antitumor activity in vitro was studied using the MTT test against HeLa and MCF-7 cell lines.Results. As a result of an electric explosion of twisted wires in an argon + oxygen gas mixture, ZnO-Ag NPs with different contents of components and the structure of Janus nanoparticles were obtained. The study of the physicochemical properties of nanoparticles showed that an increase in the silver content led to a decrease in the average particle size, an increase in their specific surface area, an increase in their photochemical activity and the ability to generate reactive oxygen species. The high antitumor activity of nanoparticles with a minimum silver content can be explained by a decrease in the size of silver fragments from 46 nm to 23 nm and a decrease in the average particle size from 92 nm to 54 nm. A decrease in the size of NPs and their components contributes to an increase in their solubility and, accordingly, cytotoxicity. In addition, a decrease in the size of crystallites makes it possible to increase the number and length of the ZnO-Ag interface.Conclusion. In the present study, bicomponent ZnO–Ag NPs were synthesized using the joint electric explosion of zinc and silver wires in a mixed atmosphere of argon and oxygen. A study of the physicochemical properties of nanoparticles was carried out and it was found that they all have the structure of Janus nanoparticles, an average size of 54 to 92 nm, and photochemical activity and the ability to generate ROS. Using the MTT test, the antitumor activity of NPs was confrmed using MCF-7 and HeLa cell lines. The high effciency of ZnO-Ag NPs containing 20% wt. silver indicates the possibility of using these NPs in antitumor therapy. Введение. Наночастицы оксида цинка и серебра являются перспективными противоопухолевыми агентами, применение которых может усилить современные подходы к лечению рака. Применяя бикомпонентные наночастицы ZnO-Ag, можно увеличить эффективность благодаря возникновению синергетического противоопухолевого эффекта. Среди основных физико-химических параметров, влияющих на противоопухолевую активность наночастиц, можно выделить их размер и распределение компонентов внутри частицы или их микроструктуру, однако данные аспекты до сих пор являются мало изученными.Целью исследования является синтез наночастиц ZnO-Ag при помощи электровзрывной технологии и исследование in vitro противоопухолевой активности НЧ в отношении аденокарциномы протоков молочной железы MCF-7 (ATCC HTB-22) и клеточной линии HeLa.Материал и методы. Для получения наночастиц ZnO-Ag использовали совместный электрический взрыв скрутки проволок цинка и серебра в смешанной атмосфере аргона и кислорода. Физико-химические свойства исследованы при помощи рентгенофазового анализа, тепловой десорбции азота, просвечивающей электронной микроскопии. Противоопухолевую активность in vitro исследовали при помощи МТТтеста в отношении клеточных линий HeLa и MCF-7.Результаты. В результате электрического взрыва скрутки цинковой и серебряной проволок в газовой смеси аргон + кислород получены НЧ ZnO-Ag с различным содержанием компонентов и структурой янус-наночастиц. Исследование физико-химических свойств наночастиц показало, что увеличение содержания серебра приводит к снижению среднего размера частиц, увеличению их удельной поверхности, увеличению их фотохимической активности и способности генерировать активные формы кислорода. Высокую противоопухолевую активность НЧ с минимальным содержанием серебра можно объяснить снижением размера фрагментов серебра с 46 до 23 нм и снижением среднего размера частиц с 92 до 54 нм. Снижение размера НЧ и их компонентов способствует увеличению их растворимости и, соответственно, цитотоксичности. Кроме того, снижение размера кристаллитов позволяет увеличить количество и протяженность границы раздела фаз ZnO-Ag.Заключение. Бикомпонентные НЧ ZnO-Ag были синтезированы при помощи совместного электрического взрыва цинковой и серебряной проволок в смешанной атмосфере аргона и кислорода. При исследовании физико-химических свойств наночастиц установлено, что они имеют структуру янус-наночастиц, средний размер от 54 до 92 нм, обладают фотохимической активностью и способностью генерировать АФК. При помощи МТТ-теста подтверждена противоопухолевая активность НЧ с использованием клеточных линий MCF-7 и HeLa. Высокая эффективность НЧ ZnO-Ag, содержащих 20 % серебра, указывает на возможность применения данных НЧ в противоопухолевой терапии.