Facile and reversible double dearomatization of pyridines in non-phosphine MnI complexes with N,S-donor pyridinophane ligand

Single and double dearomatization of pyridine rings was observed in Mn(I) complexes with an N2S2 pyridinophane ligand via deprotonation of one or two CH2 arms, respectively. In contrast to other N,S-donor pincer-like systems, the dearomatized (N2S2)Mn species were found to be stable, with the dearomatization being reversible

Aryl–X Bond-Forming Reductive Elimination from High-Valent Mn–Aryl Complexes

C–X bond reductive elimination and oxidative addition are key steps in many catalytic cycles for C–H functionalization catalyzed by precious metals; however, engaging first row transition metals in these overall 2e– processes remains a challenge. Although high-valent Mn aryl species have been implicated in Mn-catalyzed C–H functionalization, the nature and reactivity of such species remain unelucidated. In this work, we report rare examples of stable, cyclometalated monoaryl MnIII complexes obtained through clean oxidative addition of Ar–Br to MnI(CO)5Br. These isolated MnIII–Ar complexes undergo unprecedented 2e– reductive elimination of the Ar–X (X = Br, I, and CN) bond and MnII induced by 1e– oxidation, presumably via transient reactive MnIV species. Mechanistic studies suggest a nonradical pathway

ПРОДУКЦИЯ ФАКТОРОВ РОСТА И ДЕСКВАМАЦИЯ ЭНДОТЕЛИОЦИТОВ В СЕРДЦЕ ПРИ ИШЕМИЧЕСКОЙ КАРДИОМИОПАТИИ

oai:oai.kpccz.elpub.ru:article/1324Highlights Dysregulation of angiogenesis may be the pathogenetic factor of ischemic cardiomyopathy (ICMP). Aim. To determine the content of growth factors and desquamated endothelial cells (DEC) in the blood from the coronary sinus and ulnar vein in association with the number of progenitor endothelial cells (PEC) in the blood from the ulnar vein in patients with coronary heart disease (CHD), suffering and not suffering from ICMP.Methods. The study included 30 patients with ICMР and 22 patients with CHD, and 18 healthy donors. The content of DEC (CD45–CD146+) was determined in blood from the cubital vein (peripheral) and coronary sinus, and the content of DEC (CD14+CD34+VEGFR2+) was determined in peripheral blood by flow cytometry (antibodies “BD Biosciences”, USA). The concentrations of VEGF-A, VEGF-B, PDGF, SDF-1, SCF, FGF-1, TGF-β1 in blood plasma from both locations were evaluated by multiplex analysis (set “Cloud-Clone Corp.”, USA).Results. The content of DEC in peripheral blood was elevated in patients with CHD of both groups, and in patients with ICMP in sinus blood was higher than in peripheral. At the same time, in patients with CHD without cardiomyopathy, an excess of PEC and SDF-1 in the blood from the ulnar vein was established in combination with an increase in the concentration of PDGF and a decrease in the content of VEGF-B in the blood from the coronary sinus relative to the parameters of systemic blood flow. In patients with ICMP, these changes were not detected, but there was an increase in the concentration of TGF-β1 in sinus blood compared with peripheral blood. Regardless of the presence of ICMP, the concentration of SCF, FGF-1, VEGF-A in the blood from the ulnar vein corresponded to the norm and that in sinus blood; the content of VEGF-A in the coronary bloodstream exceeded its systemic level.Conclusion. In patients with ICMP, desquamation of the coronary vascular endothelium is enhanced against the background of violations of its repair processes due to insufficient (relative to CHD without cardiomyopathy) mobilization of PEC from the bone marrow due to the absence of an excess of SDF-1 in the blood and their insufficient homing into the myocardium due to weak PDGF production in the heart.Основные положенияПатогенетическим фактором ишемической кардиомиопатии может быть нарушение регуляции ангиогенеза. Цель. Определить содержание факторов роста и десквамированных эндотелиальных клеток (ДЭК) в крови из коронарного синуса и локтевой вены в ассоциации с численностью прогениторных эндотелиальных клеток (ПЭК) в крови из локтевой вены у больных ишемической болезнью сердца (ИБС), страдающих и не страдающих ишемической кардиомиопатией (ИКМП).Материалы и методы. В исследование включили 30 пациентов с ИБС и ИКМП, 22 больных ИБС без ИКМП, 18 здоровых доноров. Содержание ДЭК (CD45–CD146+) определяли в крови из локтевой вены (периферическая) и коронарного синуса (синусовая), а содержание ПЭК (CD14+CD34+VEGFR2+) – в периферической крови методом проточной цитофлуориметрии (антитела BD Biosciences, США). В плазме обоих образцов крови оценивали концентрацию VEGF-A, VEGF-B, PDGF, SDF-1, SCF, FGF-1, TGF-β1 методом мультиплексного анализа (набор Cloud-Clone Corp., США).Результаты. Содержание ДЭК в периферической крови было повышенным у больных ИБС обеих групп, а в синусовой крови у пациентов с ИКМП было выше, чем в периферической. У больных ИБС без ИКМП установлен избыток ПЭК и SDF-1 в крови из локтевой вены в сочетании с увеличением концентрации PDGF и снижением содержания VEGF-В в крови из коронарного синуса относительно параметров системного кровотока. У пациентов с ИКМП данные изменения не выявлены, но отмечен рост концентрации TGF-β1 в синусовой крови по сравнению с периферической. Вне зависимости от ИКМП концентрация SCF, FGF-1, VEGF-А в крови из локтевой вены соответствовала норме и таковой в синусовой крови; содержание VEGF-А в коронарном кровотоке превышало системный уровень.Заключение. При ИКМП усилена десквамация эндотелия коронарных сосудов на фоне нарушений его репарации за счет недостаточной (относительно ИБС без ИКМП) мобилизации ПЭК из костного мозга ввиду отсутствия избытка SDF-1 в крови и недостаточного их хоминга в миокард вследствие слабой продукции PDGF в сердце

Quantum dots in bio-imaging and drug delivery

This work explores a range of bionanomaterials, with particular attention to their influence on cell growth, function and fate. Also the issue of intracellular nanoparticles quantification has been addressed in experimental and model approach. Ternary V-VI-VII semiconductor material SbSI has been investigated for its capacity to replace existing convenient II-VI CdTe, which is commonly used for engineered Quantum Dots (QDs). It remains unclear how QD uptake and cell fate are influenced by QD parameters such as size, composition, coating, concentration, and time of exposure. We have investigated experimentally and theoretically the toxic effects of intracellular QDs on RAW264.7 cell line. We have performed comprehensive study of QDs uptake dynamics and kinetics by monocyte/macrophage cells in physiological media conditions depending on particles size, composition, concentration, and exposure time using flow cytometry as quantification method. Number of cellular and immune responses was measured at the same time by multi-color approach. Was profiled the distribution of live, necrotic, early and late apoptotic cells under different experimental conditions. Pro-inflammatory surface markers CD80/86 were profiled as macrophage activation parameter. Flow cytometry has been shown as quick unbiased evaluation method of ingested particles on population level. We explained sudden drop in surface markers expression related to QDs uptake and cell function profile. The model parameters enabled a convenient quantitative evaluation of the toxicity of the various types of QDs, and good agreement was found between theoretical and experimental results. We have developed water-based ultrasonic synthesis of micro-scale SbSI particles to bring it down to submicro level. Also was made successful attempt to control crystal growth of particles with various dimensions were obtained. As-prepared micro- and sub-micro crystals were broken down to nanoparticles with broad absorption. The potential cytotoxicity of different fractions was tested on RAW264.7 monocytes

C–C Bond Elimination from High-Valent Mn Aryl Complexes

Manganese complexes have been considered as a cheap and readily available alternative to commonly used precious metal catalysts in C–C bond coupling reactions. Although high-valent Mn aryl intermediates have been proposed in such reactions, a mechanistic understanding of possible organometallic intermediates in Mn-mediated C–C coupling is still lacking due to their high reactivity. We report the synthesis of stable, isolable Mn(III) aryl complexes obtained by oxidative addition of aryl bromide or aryl chloride. These complexes react with a range of organometallic alkylating or arylating reagents (alkyl and aryl Grignard reagents, MeLi, ZnMe2) to undergo C(sp2)–C(sp3) or C(sp2)–C(sp2) bond coupling, and a preliminary catalytic system could be demonstrated. The reagent scope and yield of the C(sp2)–C(sp3) coupled product can further be increased by addition of TEMPO as an oxidant, generating alkyl radicals

Effects of Polydopamine Functionalization on Boron Nitride Nanotube Dispersion and Cytocompatibility

Boron nitride nanotubes (BNNTs) have unique physical properties, of value in biomedical applications; however, their dispersion and functionalization represent a critical challenge in their successful employment as biomaterials. In the present study, we report a process for the efficient disentanglement of BNNTs via a dual surfactant/polydopamine (PD) process. High-resolution transmission electron microscopy (HR-TEM) indicated that individual BNNTs become coated with a uniform PD nanocoating, which significantly enhanced dispersion of BNNTs in aqueous solutions. Furthermore, the cytocompatibility of PD-coated BNNTs was assessed in vitro with cultured human osteoblasts (HOBs) at concentrations of 1, 10, and 30 μg/mL and over three time-points (24, 48, and 72 h). In this study it was demonstrated that PD-functionalized BNNTs become individually localized within the cytoplasm by endosomal escape and that concentrations of up to 30 μg/mL of PD-BNNTs were cytocompatible in HOBs cells following 72 h of exposure