Water-soluble hybrid materials based on {Mo₆X₈}⁴⁺ (X = Cl, Br, I) cluster complexes and sodium polystyrene sulfonate

Development of water-soluble forms of octahedral molybdenum clusters {Mo₆X₈}⁴⁺ (X = Cl, Br, I) is strongly motivated by the tremendous potential that these complexes have for biological applications, namely as agents for bioimaging and photodynamic therapy. In these work we report the first water-soluble hybrid materials, which represent sodium polystyrene sulfonate doped by molybdenum clusters, and evaluation of their photophysical and biological properties (dark and photoinduced cytotoxicity and cellular uptake) with the use of cervical cancer (HeLa) and human epidermoid larynx carcinoma (Hep-2) cell-lines as models

Hexaazide octahedral molybdenum cluster complexes: synthesis, properties and the evidence of hydrolysis

This article reports the synthesis, crystal structure of new molybdenum hexaazide cluster complex (ⁿBu₄N)₂[{Mo₆I₈}(N₃)₆] (3) and comparison of its photophysical and electrochemical properties to those of earlier reported analogues (ⁿBu₄N)₂[{M₆X₈}(N₃)₆] (X = Cl, Br). Additionally, the dimerisation of 3 as a result of hydrolysis was revealed by mass spectrometry and single crystal X-Ray diffraction. Indeed, the structurally characterised compound (ⁿBu₄N)₄[{Mo₆I₈}(N₃)₅)₂O] represents the first example of oxo-bridged dimer of octahedral molybdenum clusters complexes

A comparative study of hydrophilic phosphine hexanuclear rhenium cluster complexes’ toxicity

Octahedral rhenium cluster compound Na2H8[{Re6Se8}(P(C2H4CONH2)(C2H4COO)2)6] has recently emerged as a very promising X-ray contrast agent for biomedical applications. However, the synthesis of this compound is rather challenging due to difficulty to control the hydrolysis of initial P(C2H4CN)3 ligand during the reaction process. Therefore, in this report we compare the in vitro and in vivo toxicity of Na2H8[{Re6Se8}(P(C2H4CONH2)(C2H4COO)2)6] with those of related compounds featuring fully hydrolysed form of the phosphine ligand, namely Na2H14[{Re6Q8}(P(C2H4COO)3)6] (Q = S or Se). Our results demonstrate that cytotoxicity and acute in vivo toxicity of the complex Na2H8[{Re6Se8}(P(C2H4CONH2)(C2H4COO)2)6] solutions were considerably lower than those of compounds with fully hydrolysed ligand P(C2H4COOH)3. Such behavior can be explained by the higher osmolality of Na2H14[{Re6Q8}(P(C2H4COO)3)6] versus Na2H8[{Re6Se8}(P(C2H4CONH2)(C2H4COO)2)6]

A comparative study of optical properties and X-ray induced luminescence of octahedral molybdenum and tungsten cluster complexes

© 2017 The Royal Society of Chemistry. Octahedral metal cluster complexes have high potential for biomedical applications. In order to evaluate the benefits of these moieties for combined CT/X-ray luminescence computed tomography, this paper compares photoluminescence, radiodensity and X-ray induced luminescence properties of eight related octahedral molybdenum and tungsten cluster complexes [{M 6 I 8 }L 6 ] n (where M is Mo or W and L is I - , NO 3 - , OTs - or OH - /H 2 O). This article demonstrates that despite the fact that molybdenum cluster complexes are better photoluminescence emitters, tungsten cluster complexes, in particular (Bu 4 N) 2 [{W 6 I 8 }I 6 ], demonstrate significantly higher X-ray induced luminescence due to a combination of relatively good photoluminescence properties and high X-ray attenuation. Additionally, photo-degradation of [{M 6 I 8 }(NO 3 ) 6 ] 2- was evaluated

Highly Pathogenic Avian Flu A(H5N1): State of Affairs in 2009–2012 and Forecast of Its Pandemic Potential

Avian flu is an infectious viral disease in birds that still retains its positions in some parts of Asia and Africa. This review contains summarization and analysis of facts regarding the current situation on highly pathogenic avian flu A-type subtype H5N1 among people and animals for the period of the past four years. Excess incidence rate in 2009 in Egypt, as well as cluster cases of the disease in humans, closely related in time and space, virus mutations as it spreads all over the world and diversification of the host specter, testify of the fact that this agent possesses significant pandemic potential and requires continuous close attention to provide for the well-timed detection of the occurring epidemiological, clinical and virological changes

Problematic questions in the development of specific prevention of dengue fever

Dengue fever known from literary sources since the Qin dynasty (265-420) is caused in humans when bitten by Aedes mosquitoes infected with the dengue virus (DENV) and manifests as a flu-like disease. A feverish state can be accompanied by dyspeptic disorders (nausea, vomiting, diarrhea) and a rash. Approximately 1-2% of infections are clinically presented as the most severe form – it is dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) leading to 500 thousand annual hospitalizations with a mortality rate of about 5% in endemic areas.Four genetically removed DENV serotypes (1, 2, 3, and 4) are classified as different types of viruses within the same antigen complex and have almost identical epidemiological features. In 2013 a new serotype DENV-5 was isolated.Until the 1980s in most geographical regions of the world where dengue fever was registered only one or two viral serotypes were detected as an etiological agent of the disease. Over time there is an increase in the cocirculation of four types of viruses which can serve as a key indicator of their global spread. As the “traces” of the four DENV species overlap more and more the threat of severe disease increases due to the phenomenon of antibody-dependent of infection when re-infected with a heterologous viral serotype.Development of specific dengue fever prevention has been underway since 1944 (since the discovery of viral agents of this disease) but the first and so far only licensed in 2015 tetravalent vaccine-Dengvaxia developed by the French pharmaceutical company Sanofi Pasteur has been effective in varying degrees of protection against infection with each of the viral serotypes and in addition dangerous for previously seronegative people. Research aimed at obtaining a safe and effective vaccine is continuing. Neutralizing monoclonal antibodies are a necessary tool for studying the antigenic structure of viral immunogens as base of prevention preparates against dengue fever

Optical properties of photonic crystal slabs with asymmetrical unit cell

Using the unitarity and reciprocity properties of the scattering matrix, we analyse the symmetry and resonant optical properties of the photonic crystal slabs (PCS) with complicated unit cell. We show that the reflectivity is not changed upon the 180deg-rotation of the sample around the normal axis, even in PCS with asymmetrical unit cell. Whereas the transmissivity becomes asymmetrical if the diffraction or absorption are present. The PCS reflectivity peaks to unity near the quasiguided mode resonance for normal light incidence in the absence of diffraction, depolarisation, and absorptive losses. For the oblique incidence the full reflectivity is reached only in symmetrical PCS.Comment: 5 pages, 2 Postscript figure

Luminescent silica mesoparticles for protein transduction

Unlike silica nanoparticles, the potential of silica mesoparticles (SMPs) (i.e. particles of submicron size) for biological applications in particular the in vitro (let alone in vivo) cellular delivery of biological cargo has so far not been sufficiently studied. Here we examine the potential of luminescent (namely, octahedral molybdenum cluster doped) SMPs synthesised by a simple one-pot reaction for the labelling of cells and for protein transduction into larynx carcinoma (Hep-2) cells using GFP as a model protein. Our data demonstrates that the SMPs internalise into the cells within half an hour. This results in cells that detectably luminesce via conventional methods. In addition, the particles are non-toxic both in darkness and upon photo-irradiation. The SMPs were modified to allow their functionalisation by a protein, which then delivered the protein (GFP) efficiently into the cells. Thus, the luminescent SMPs offer a cheap and trackable alternative to existing materials for cellular internalisation of proteins, such as the HIV TAT protein and commercial protein delivery agents (e.g. Pierce™)

INFLUENZA VIRUS EPIDEMIOLOGICAL SITUATION IN THE SOUTH OF WESTERN SIBERIA IN 2011-2012

In the result of the monitoring for influenza in the Novosibirsk region during the season 2011-2012 85 strains of influenza virus on the culture of MDCK cells were isolated: 79 strains A (H3N2) and 6 strains of influenza virus B (five strains belonged to the Yamagata line and. 1 strain belonged to the Victoria line). During the entire epidemic season 2011-2012 on the territory of the Novosibirsk region no strains of influenza A (H1N1) pdm09 were allocated. For molecular genetic analysis 3 strains of influenza A (H3N2) were selected. We determined full nucleotide sequence of NA and. HA genes encoding respective surface glycoproteins of influenza virus, as well as the comparative analysis of amino acid sequences of these proteins to the strains of influenza A (H3N2), vaccine strain and. the strain A/Victoria/361/2011 earlier seasons, for which diagnostic serum were obtained