Cribado de alto rendimiento (hts) de una librería de pequeñas moléculas para la identificación de moléculas anti-EBOV

Motivation: Ebola virus (EBOV) is considered as the prototypical pathogen of viral hemorrhagic fever, causing severe disease and mortality rates as high as 90%. The implementation of different High-Throughput Screening systems to avoid the use of BSL-4 facilities will promote the generation of lead molecules and so the development of new therapeutics for EBOV within the next few years. The goals of the present project are directed to the discovery of new antiviral drugs against EBOV by using HTS of different libraries of small compounds, some of which have previously been an excellent source of potent antiviral compounds, by the use of a retroviral pseudotype particle (pEBOV-GFP) carrying the EBOV glycoprotein (GP).  Methods: Retroviral pseudotypes were generated by the transfection with the HIV gag-pol plasmid, pCMV-Δ8.91, the EBOV GP expression construct, pCAGGS-EBOV, and the green fluorescence protein (GFP) reporter construct, pCSGW at a ratio of 1.1:0.5:0.75 (core:envelope:reporter). At we carryed out at the IBiS the screening of different libraries of small compounds of different nature. The libraries of small compounds to be screened were synthesized by: i) the Medicinal Chemistry Institute of Madrid (IQM-CSIC), ii) the Unit of Molecular Chemistry and Pharmacology of the Institute for Research in Biomedicine of Barcelona (IRB), and iii) the Group of Organic Chemistry at the Faculty of Pharmacy of the University of Seville. Antiviral activivity was evaluated by pEBOV-mediated GFP expression.  Results: After the evaluation of 60 compounds, only compounds 4, 10, 17, 23, 33, 34, 125, 126, 279, 284, 298, 372, 385, 414 and 42 showed a significant (> 50%) inhibition of pEBOV-GFP entry (50 µM), presenting values of cytotoxicity (CC50) greater than 100 mM, therefore considered safe. Compounds 21, 371, 82, despite showing optimal inhibition percentages at 50 µM, presented CC50 values lower than our 100 µM threshold and because of that they were excluded from further evaluations. Conclusions: Although the antiviral activity of molecules identified by these system has to be confirmed against the wild-type EBOV, it is a useful tool to identify anti-EBOV candidates that also solves the necessity of work in BSL-4 facilities. Compounds identified in this work could potentially represent strong hit compounds for the development of a treatment for the EBOV disease

Bioactivity of wollastonite/aerogels composites obtained from a TEOS-MTES matrix

Organic-inorganic hybrid materials were synthesized by controlled hydrolysis of tetraethoxysilane (TEOS), methyltrimethoxysilane (MTES), synthetic wollastonite powders and polydimethylsiloxane (PDMS) in an ethanol solution. Aerogels were prepared from acid hydrolysis of TEOS and MTES with different volume ratio in ethanol, followed by addition of wollastonite powder and PDMS in order to obtain aerogels with 20 wt% of PDMS and 5 wt% of CaO of the total silica. Finally, when the wet gels were obtained, they were supercritically dried at 260°C and 90 bar, in ethanol. In order to obtain its bioactivity, one method for surface activation is based on a wet chemical alkaline treatment. The particular interest of this study is that we introduce hybrid aerogels, in a 1 M solution of NaOH, for 30 s at room temperature. We evaluate the bioactivity of TEOS-MTES aerogel when immersed in a static volume of simulated body fluid (SBF). An apatite layer of spherical-shaped particles of uniform size smaller than 5 microns is observed to form on the surface of the aerogels after 25 days soaking in SBF.Ministerio de Ciencia e Innovación MAT2005-01583Junta de Andalucía TEP 79

Dielectric spectroscopy of natural rubber-cellulose II nanocomposites

[EN] Nanocomposite materials obtained from natural rubber (NR) reinforced with different amounts of cellulose II nanoparticles (in the range of 0 to 30 phr) are studied by dielectric spectroscopy (DS). For comparative purposes the pure materials, NR and cellulose, are also investigated. The dielectric spectra of the nanocomposites exhibit: (a) two overlapped ¿-relaxations associated respectively with the dynamic glass transitions of NR (faster process) and of the lipid present in NR; (b) a ß-relaxation associated with local chain dynamics of cellulose and (c) a relaxation process associated to the presence of traces of water in cellulose. The spectra exhibit conductivity phenomena at low frequencies and high temperatures. The samples were also studied in the dry state. An explanation is given concerning the cellulose effect on the dielectric properties of the dry and wet nanocomposites. © 2010 Elsevier B.V.All rights reserved.The authors gratefully acknowledge CICYT for Grant No. MAT2008-06725-C03-03 and Generalitat Valenciana for Grant No. ACOMP/2010/204.Ortiz Serna, MP.; Díaz Calleja, R.; Sanchis Sánchez, MJ.; Riande, E.; Numes, R.; Martins, A.; Visconte, L. (2011). Dielectric spectroscopy of natural rubber-cellulose II nanocomposites. Journal of Non-Crystalline Solids. 357(2):598-604. doi:10.1016/j.jnoncrysol.2010.06.044S598604357

A genome-wide association study on liver stiffness changes during hepatitis c virus infection cure

Liver stiffness (LS) at sustained virological response (SVR) after direct-acting antivirals (DAA)-based therapy is a predictor of liver events in hepatitis C virus (HCV)-infected patients. The study aim was to identify genetic factors associated with LS changes from the moment of starting anti-HCV therapy to SVR. This prospective study included HCV-infected patients from the GEHEP 011 cohort who achieved SVR with DAA-based therapy, with LS pre-treatment ≥9.5 kPa and LS measurement available at SVR. Plink and Magma software were used to carry out genome-wide single-nucleotide polymorphism (SNP)-based and gene-based association analyses, respectively. The ShinyGO application was used for exploring enrichment in Gene Ontology (GO) categories for biological processes. Overall, 242 patients were included. Median (quartile 1, quartile 3) LS values at pre-treatment and at SVR were 16.8 (12, 28) kPa and 12.0 (8.5, 19.3) kPa, respectively. Thirty-five SNPs and three genes reached suggestive association with LS changes from the moment of starting anti HCV therapy to SVR. GO categories related to DNA packaging complex, DNA conformation change, chromosome organization and chromatin organization were significantly enriched. Our study reports possible genetic factors associated with LS changes during HCV-infection cure. In addition, our results suggest that processes related to DNA conformation are also involved in these changes

Spin diffusion versus proximity effect at ferromagnet/superconductor La_(0.7)Ca_(0.3)MnO_(3)/YBa_(2)Cu_(3)O_(7-δ) interfaces

We report on the interplay between magnetism and superconductivity in La_(0.7)Ca_(0.3)MnO_(3)/YBa_(2)Cu_(3)O_(7) structures. We have grown heterostructures (bilayers and trilayers) with a constant thickness of the ferromagnetic layer of 40 unit cells (15 nm) and changing the thickness of the superconductor between 1 (1.2 nm) and 40 unit cells (48 nm). The critical temperature of the bilayers decreases when the thickness of the superconductor is reduced below 10 unit cells, thus providing an estimate of the length scale of superconductivity suppression by spin-polarized quasiparticles in YBa_(2)Cu_(3)O_(7-δ) (YBCO) of 10 nm, much larger than the coherence length. For thickness of the YBCO layer smaller than 4 unit cells; a second mechanism of superconductivity depression comes into play, probably related to the ferromagnetic/superconducting proximity effect. The relative importance in depressing the critical temperature of intrinsic mechanisms (quasiparticle diffusion and proximity effect) and extrinsic ones (intralayer disorder, interface roughness, or reduced dimensionality of ultrathin layers) is discussed

Fluorescent dye labeling changes the biodistribution of cell-targeted nanoparticles

Fluorescent dye labeling is a common strategy to analyze the fate of administered nanoparticles in living organisms. However, to which extent the labeling processes can alter the original nanoparticle biodistribution has been so far neglected. In this work, two widely used fluorescent dye molecules, namely, ATTO488 (ATTO) and Sulfo-Cy5 (S-Cy5), have been covalently attached to a well-characterized CXCR4-targeted self-assembling protein nanoparticle (known as T22-GFP-H6). The biodistribution of labeled T22-GFP-H6-ATTO and T22-GFP-H6-S-Cy5 nanoparticles has been then compared to that of the non-labeled nanoparticle in different CXCR4+ tumor mouse models. We observed that while parental T22-GFP-H6 nanoparticles accumulated mostly and specifically in CXCR4+ tumor cells, labeled T22-GFP-H6-ATTO and T22-GFP-H6-S-Cy5 nanoparticles showed a dramatic change in the biodistribution pattern, accumulating in non-target organs such as liver or kidney while reducing tumor targeting capacity. Therefore, the use of such labeling molecules should be avoided in target and non-target tissue uptake studies during the design and development of targeted nanoscale drug delivery systems, since their effect over the fate of the nanomaterial can lead to considerable miss-interpretations of the actual nanoparticle biodistribution

Wide band-gap tuning Cu2ZnSn1-xGexS4 single crystals: optical and vibrational properties

The linear optical properties of Cu2ZnSn1-xGexS4 high quality single crystals with a wide range of Ge contents (x = 0.1, 0.3, 0.5, 0.7, 0.9 and 1) have been investigated in the ultraviolet and near infrared range using spectroscopic ellipsometry measurements. From the analysis of the complex dielectric function spectra it has been found that the bandgap E0 increases continuously from 1.49 eV to 2.25 eV with the Ge content. Furthermore, the evolution of the interband transitions E1A and E1B has been also determined. Raman scattering using three different excitation wavelengths and its analysis have been performed to confirm the absence of secondary phases in the samples, and to distinguish between stannite, wurtzite, wurzstannite and kesterite structures. Additionally, the analysis of the high resolution Raman spectra obtained in samples with different [Ge]/([Ge]+[Sn]) ratios allows describing a bimodal behavior of the dominant A modes. The understanding of the incorporation of Ge into the Cu2ZnSnS4 lattice is fundamental in order to develop efficient bandgap engineering of these compounds towards the fabrication of kesterite based solar cells with enhanced performanc

Protocol for intervention-free quantification of protein turnover rate by steady-state modeling

Protein turnover rate is difficult to obtain experimentally. This protocol shows how to mathematically model turnover rates in an intervention-free manner given the ability to quantify mRNA and protein expression from initiation to homeostasis. This approach can be used to calculate production and degradation rates and to infer protein half-life. This model was successfully employed to quantify turnover during Drosophila embryogenesis, and we hypothesize that it will be applicable to diverse in vivo or in vitro systems

Effect of milling process on particle size, morphology and magnetization in non-stoichiometric Fe2O3-MnO2.

High-energy milling process on ceramic material was analyzed, it process generate modifications on morphology and particle size, the process showed the last one relation with the crystallite size, about of structural analysis Rietveld refinement let identify anisotropy with the variations on crystalline planes and deformations occasioned by milling process, the particle size decrease with the process, similar tendency was observed on the images obtained by Scanning Electronic Microscopy, an result in this study was the variation on magnetization without chemical reaction under non-stoichiometric conditions and the agglomerates sizes observed on samples it is by process

Origin of the inverse spin-switch behavior in manganite/cuprate/manganite trilayers

We studied ferromagnet/superconductor/ferromagnet trilayers based on La_(0.7)Ca_(0.3)MnO_(3) manganite and YBa_(2)Cu_(3)O_(7−δ) (YBCO) high-T_(c) cuprate with magnetoresistance and magnetization measurements. We find an inverse superconducting spin-switch behavior, where superconductivity is favored for parallel alignment of the magnetization in the ferromagnetic layers. We argue that this inverse superconducting spin switch originates from the transmission of spin-polarized carriers into the superconductor. In this picture, the thickness dependence of the magnetoresistance yields the spin-diffusion length in YBCO as 13 nm. A comparison of bilayers and trilayers allows ruling out the effect of the stray fields of the domain structure of the ferromagnet as the source of the inverse superconducting spin switch