Design and synthesis of benzimidazole phenol-porphyrin dyads for the study of bioinspired photoinduced proton-coupled electron transfer

Benzimidazole phenol-porphyrin dyads have been synthesized to study proton-coupled electron transfer (PCET) reactions induced by photoexcitation. High-potential porphyrins have been chosen to model P680, the photoactive chlorophyll cluster of photosynthetic photosystem II (PSII). They have either two or three pentafluorophenyl groups at the meso positions to impart the high redox potential. The benzimidazole phenol (BIP) moiety models the Tyrz-His190 pair of PSII, which is a redox mediator that shuttles electrons from the water oxidation catalyst to P680•+. The dyads consisting of a porphyrin and an unsubstituted BIP are designed to study one-electron one-proton transfer (E1PT) processes upon excitation of the porphyrin. When the BIP moiety is substituted with proton-accepting groups such as imines, one-electron two-proton transfer (E2PT) processes are expected to take place upon oxidation of the phenol by the excited state of the porphyrin. The bis-pentafluorophenyl porphyrins linked to BIPs provide platforms for introducing a variety of electron-accepting moieties and/or anchoring groups to attach semiconductor nanoparticles to the macrocycle. The triads thus formed will serve to study the PCET process involving the BIPs when the oxidation of the phenol is achieved by the photochemically produced radical cation of the porphyrin.Fil: Mora, Sabrina Jimena. Arizona State University; Estados Unidos. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Heredia, Daniel Alejandro. Universidad Nacional de Río Cuarto. Instituto para el Desarrollo Agroindustrial y de la Salud. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto para el Desarrollo Agroindustrial y de la Salud; ArgentinaFil: Odella, Emmanuel. Arizona State University; Estados Unidos. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; ArgentinaFil: Vrudhula, Uma. Arizona State University; Estados UnidosFil: Gust, Devens. Arizona State University; Estados UnidosFil: Moore, Thomas A.. Arizona State University; Estados UnidosFil: Moore, Ana L.. Arizona State University; Estados Unido

Effect of Bone Marrow-Derived Mesenchymal Stem Cells on Endotoxin-Induced Oxidation of Plasma Cysteine and Glutathione in Mice

Bone marrow-derived mesenchymal stem cells (BMDMSC) are emerging as a therapeutic modality in various inflammatory disease states, including acute lung injury (ALI). A hallmark of inflammation, and a consistent observation in patients with ALI, is a perturbation in the systemic redox environment. However, little is known about the effects of BMDMSC on the systemic redox status. The objective of the present study was to determine whether exogenously infused BMDMSC protect against endotoxin-induced oxidation of plasma cysteine (Cys) and glutathione (GSH) redox states. To determine the effect on the redox state if BMDMSC, mice received endotoxin intraperitoneally (1 mg/kg), followed by intravenous infusion of either 5 × 105 BMDMSC or an equal volume of saline solution. Control mice received intraperitoneal endotoxin followed by 5 × 105 lung fibroblasts given intravenously. Cys, cystine (CySS), GSH, and glutathione disulfide (GSSG) concentrations were determined by HPLC. Results showed sequential preservation of plasma Cys and GSH levels in response to BMDMSC infusion. The data show that BMDMSC infusion leads to a more reducing Cys and GSH redox state. The findings are the first to demonstrate that BMDMSC have antioxidant effects in vivo, and add to our understanding of the systemic effects of BMDMSC in lung injury

Arrhythmia Mechanism and Scaling Effect on the Spectral Properties of Electroanatomical Maps with Manifold Harmonics

[EN] Introduction: Spatial and temporal processing of intracardiac electrograms provides relevant information to support the arrhythmia ablation during electrophysio-logical studies. Current cardiac navigation systems (CNS) and electrocardiographic imaging (ECGI) build detailed 3-D electroanatomical maps (EAM), which represent the spatial anatomical distribution of bioelectrical features, such as activation time or voltage. Objective: We present a principled methodology for spectral analysis of both EAM geometry and bioelectrical feature in CNS or ECGI, including their spectral representation, cutoff frequency, or spatial sampling rate (SSR). Methods: Existing manifold harmonic techniques for spectral mesh analysis are adapted to account for a fourth dimension, corresponding to the EAM bioelectrical feature. Appropriate scaling is required to address different magnitudes and units. Results: With our approach, simulated and real EAM showed strong SSR dependence on both the arrhythmia mechanism and the cardiac anatomical shape. For instance, high frequencies increased significantly the SSR because of the "early-meets-late" in flutter EAM, compared with the sinus rhythm. Besides, higher frequency components were obtained for the left atrium (more complex anatomy) than for the right atrium in sinus rhythm. Conclusion: The proposed manifold harmonics methodology opens the field toward new signal processing tools for principled EAM spatiofeature analysis in CNS and ECGI, and to an improved knowledge on arrhythmia mechanisms.This work was partly supported by Spanish Research Projects TEC2013-48439-C4-1-R, TEC2016-75361-R, and TEC2016-75161-C2-1-4.Sanroman-Junquera, M.; Mora-Jimenez, I.; Garcia-Alberola, A.; Caamano, AJ.; Trénor Gomis, BA.; Rojo-Alvarez, JL. (2018). Arrhythmia Mechanism and Scaling Effect on the Spectral Properties of Electroanatomical Maps with Manifold Harmonics. IEEE Transactions on Biomedical Engineering (Online). 65(4):723-732. https://doi.org/10.1109/TBME.2017.2716189S72373265

Twist: A Regulator of Epithelial-Mesenchymal Transition in Lung Fibrosis

BACKGROUND: Several studies have implicated viral infection as an important factor in the pathogenesis of IPF and related fibrotic lung disorders. Viruses are thought to cause epithelial cell injury and promote epithelial-mesenchymal transition (EMT), a process whereby differentiated epithelial cells undergo transition to a mesenchymal phenotype, and considered a source of fibroblasts in the setting of lung injury. We have demonstrated an association between the epithelial injury caused by chronic herpes virus infection with the murine gamma-herpes virus, MHV68, and lung fibrosis. We hypothesize that EMT in this model of virus-induced pulmonary fibrosis is driven by the expression of the transcription factor Twist. METHODS/FINDINGS: In vitro MHV68 infection of murine lung epithelial cells induced expression of Twist, and mesenchymal markers. Stable overexpression of Twist promoted EMT in MLE15 lung epithelial cells. Transient knockdown expression of Twist resulted in preservation of epithelial phenotype after in vitro MHV68 infection. In concordance, high expression of Twist was found in lung epithelial cells of MHV68 infected mice, but not in mock infected mice. Alveolar epithelial cells from lung tissue of idiopathic pulmonary fibrosis (IPF) patients were strongly positive for Twist. These cells demonstrated features of EMT with low expression of E-cadherin and upregulation of the mesenchymal marker N-cadherin. Finally, IPF tissue with high Twist protein levels was also positive for the herpesvirus, EBV. CONCLUSIONS/SIGNIFICANCE: We conclude that Twist contributes to EMT in the model of virus-induced pulmonary fibrosis. We speculate that in some IPF cases, gamma-herpes virus infection with EBV might be a source of injury precipitating EMT through the expression of Twist

Enhancement of Magnetic Hyperthermia by Mixing Synthetic Inorganic and Biomimetic Magnetic Nanoparticles

In this work we report on the synthesis and characterization of magnetic nanoparticles of two distinct origins, one inorganic (MNPs) and the other biomimetic (BMNPs), the latter based on a process of bacterial synthesis. Each of these two kinds of particles has its own advantages when used separately with biomedical purposes. Thus, BMNPs present an isoelectric point below neutrality (around pH 4.4), while MNPs show a zero-zeta potential at pH 7, and appear to be excellent agents for magnetic hyperthermia. This means that the biomimetic particles are better suited to be loaded with drug molecules positively charged at neutral pH (notably, doxorubicin, for instance) and releasing it at the acidic tumor environment. In turn, MNPs may provide their transport capabilities under a magnetic field. In this study it is proposed to use a mixture of both kinds of particles at two different concentrations, trying to get the best from each of them. We study which mixture performs better from different points of view, like stability and magnetic hyperthermia response, while keeping suitable drug transport capabilities. This composite system is proposed as a close to ideal drug vehicle with added enhanced hyperthermia response.We wish to thank FPU2016 grant (Ref. FPU16-04580), RYC-2014-6901 (MINECO, Spain), CGL2016-76723 (MINECO, Spain and FEDER, EU), Unidad Científica de Excelencia UCE-PP2016-05 (UGR) and Plan Propio Beca de iniciación a la investigación para estudiantes de master (UGR)

Humic-like substances from urban waste as auxiliaries for photo-Fenton treatment: a fluorescence EEM-PARAFAC study

[EN] In this work, analysis of excitation-emission-matrices (EEM) has been employed to gain further insight into the characterization of humic like substances (HLS) obtained from urban wastes (soluble bio-organic substances, SBOs). In particular, complexation of these substances with iron and changes along a photo-Fenton process have been studied. Recorded EEMs were decomposed by using parallel factor analysis (PARAFAC). Three fluorescent components were identified by PARAFAC modeling of the entire set of SBO solutions studied. The EEM peak locations (lambda(ex)/lambda(em)) of these components were 310-330 nm/400-420 nm (C1), 340-360 nm/450-500 nm (C2), and 285 nm/335-380 nm (C3). Slight variations of the maximum position of each component with the solution pH were observed. The interaction of SBO with Fe(III) was characterized by determining the stability constants of the components with Fe(III) at different pH values, which were in the order of magnitude of the ones reported for humic substances and reached their highest values at pH = 5. Photochemical experiments employing SBO and Fe(III), with and without H2O2, showed pH-dependent trends for the evolution of the modeled components, which exhibited a strong correlation with the efficiency reported for the photo-Fenton processes in the presence of SBO at different pH values.This work was supported by Generalitat Valenciana, Conselleria d'Ecuacio, Cultura i esport, Spain (GV/2015/074), Spanish Ministerio de Economia y Competitividad (CTQ2015-69832-C4-4-R) and by the Marie Sklodowska-Curie Research and Innovation Staff Exchange project funded by the European Commission H2020-MSCA-RISE-2014 (Project number: 645551). F. S. G. E. and L. C. are researchers from CONICET, Argentina.García-Ballesteros, S.; Constante, M.; Vicente Candela, R.; Mora Carbonell, M.; Amat Payá, AM.; Arques Sanz, A.; Carlos, L.... (2017). Humic-like substances from urban waste as auxiliaries for photo-Fenton treatment: a fluorescence EEM-PARAFAC study. Photochemical & Photobiological Sciences. 16:38-45. https://doi.org/10.1039/c6pp00236fS384516Malato, S., Fernández-Ibáñez, P., Maldonado, M. I., Blanco, J., & Gernjak, W. (2009). Decontamination and disinfection of water by solar photocatalysis: Recent overview and trends. Catalysis Today, 147(1), 1-59. doi:10.1016/j.cattod.2009.06.018WANG, J. L., & XU, L. J. (2012). Advanced Oxidation Processes for Wastewater Treatment: Formation of Hydroxyl Radical and Application. Critical Reviews in Environmental Science and Technology, 42(3), 251-325. doi:10.1080/10643389.2010.507698Pignatello, J. J., Oliveros, E., & MacKay, A. (2006). 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Applied Catalysis B: Environmental, 179, 372-379. doi:10.1016/j.apcatb.2015.05.025Bernabeu, A., Palacios, S., Vicente, R., Vercher, R. F., Malato, S., Arques, A., & Amat, A. M. (2012). Solar photo-Fenton at mild conditions to treat a mixture of six emerging pollutants. Chemical Engineering Journal, 198-199, 65-72. doi:10.1016/j.cej.2012.05.056Klamerth, N., Malato, S., Maldonado, M. I., Agüera, A., & Fernández-Alba, A. (2011). Modified photo-Fenton for degradation of emerging contaminants in municipal wastewater effluents. Catalysis Today, 161(1), 241-246. doi:10.1016/j.cattod.2010.10.074Voelker, B. M., Morel, F. M. M., & Sulzberger, B. (1997). Iron Redox Cycling in Surface Waters:  Effects of Humic Substances and Light. Environmental Science & Technology, 31(4), 1004-1011. doi:10.1021/es9604018De la Cruz, N., Giménez, J., Esplugas, S., Grandjean, D., de Alencastro, L. F., & Pulgarín, C. (2012). Degradation of 32 emergent contaminants by UV and neutral photo-fenton in domestic wastewater effluent previously treated by activated sludge. Water Research, 46(6), 1947-1957. doi:10.1016/j.watres.2012.01.014Gomis, J., Vercher, R. F., Amat, A. M., Mártire, D. O., González, M. C., Bianco Prevot, A., … Carlos, L. (2013). Application of soluble bio-organic substances (SBO) as photocatalysts for wastewater treatment: Sensitizing effect and photo-Fenton-like process. Catalysis Today, 209, 176-180. doi:10.1016/j.cattod.2012.08.036Gomis, J., Carlos, L., Prevot, A. B., Teixeira, A. C. S. C., Mora, M., Amat, A. M., … Arques, A. (2015). Bio-based substances from urban waste as auxiliaries for solar photo-Fenton treatment under mild conditions: Optimization of operational variables. Catalysis Today, 240, 39-45. doi:10.1016/j.cattod.2014.03.034Gomis, J., Bianco Prevot, A., Montoneri, E., González, M. C., Amat, A. M., Mártire, D. O., … Carlos, L. (2014). Waste sourced bio-based substances for solar-driven wastewater remediation: Photodegradation of emerging pollutants. Chemical Engineering Journal, 235, 236-243. doi:10.1016/j.cej.2013.09.009Avetta, P., Berto, S., Bianco Prevot, A., Minella, M., Montoneri, E., Persico, D., … Arques, A. (2015). Photoinduced transformation of waste-derived soluble bio-based substances. Chemical Engineering Journal, 274, 247-255. doi:10.1016/j.cej.2015.03.126Gomis, J., Gonçalves, M. G., Vercher, R. F., Sabater, C., Castillo, M.-A., Prevot, A. B., … Arques, A. (2015). Determination of photostability, biocompatibility and efficiency as photo-Fenton auxiliaries of three different types of soluble bio-based substances (SBO). Catalysis Today, 252, 177-183. doi:10.1016/j.cattod.2014.10.015Berkovic, A. M., García Einschlag, F. S., Gonzalez, M. C., Pis Diez, R., & Mártire, D. O. (2013). Evaluation of the Hg2+binding potential of fulvic acids from fluorescence excitation–emission matrices. Photochem. Photobiol. 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Fluorescence Inner-Filtering Correction for Determining the Humification Index of Dissolved Organic Matter. Environmental Science & Technology, 36(4), 742-746. doi:10.1021/es0155276Bahram, M., Bro, R., Stedmon, C., & Afkhami, A. (2006). Handling of Rayleigh and Raman scatter for PARAFAC modeling of fluorescence data using interpolation. Journal of Chemometrics, 20(3-4), 99-105. doi:10.1002/cem.978Ryan, D. K., & Weber, J. H. (1982). Fluorescence quenching titration for determination of complexing capacities and stability constants of fulvic acid. Analytical Chemistry, 54(6), 986-990. doi:10.1021/ac00243a033Yan, M., Fu, Q., Li, D., Gao, G., & Wang, D. (2013). Study of the pH influence on the optical properties of dissolved organic matter using fluorescence excitation–emission matrix and parallel factor analysis. Journal of Luminescence, 142, 103-109. doi:10.1016/j.jlumin.2013.02.052Dryer, D. J., Korshin, G. V., & Fabbricino, M. (2008). In Situ Examination of the Protonation Behavior of Fulvic Acids Using Differential Absorbance Spectroscopy. Environmental Science & Technology, 42(17), 6644-6649. doi:10.1021/es800741uGhosh, K., & Schnitzer, M. (1981). Fluorescence Excitation Spectra and Viscosity Behavior of a Fulvic Acid and its Copper and Iron Complexes1. Soil Science Society of America Journal, 45(1), 25. doi:10.2136/sssaj1981.03615995004500010005xLyon, B. A., Cory, R. M., & Weinberg, H. S. (2014). Changes in dissolved organic matter fluorescence and disinfection byproduct formation from UV and subsequent chlorination/chloramination. Journal of Hazardous Materials, 264, 411-419. doi:10.1016/j.jhazmat.2013.10.065Poulin, B. A., Ryan, J. N., & Aiken, G. R. (2014). Effects of Iron on Optical Properties of Dissolved Organic Matter. Environmental Science & Technology, 48(17), 10098-10106. doi:10.1021/es502670rXu, H., Yan, Z., Cai, H., Yu, G., Yang, L., & Jiang, H. (2013). 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Controlling proton-coupled electron transfer in bioinspired artificial photosynthetic relays

Bioinspired constructs consisting of benzimidazole-phenol moieties bearing N-phenylimines as proton-accepting substituents have been designed to mimic the H-bond network associated with the TyrZ-His190 redox relay in photosystem II. These compounds provide a platform to theoretically and experimentally explore and expand proton-coupled electron transfer (PCET) processes. The models feature H-bonds between the phenol and the nitrogen at the 3-position of the benzimidazole and between the 1H -benzimidazole proton and the imine nitrogen. Protonation of the benzimidazole and the imine can be unambiguously detected by infrared spectroelectrochemistry (IRSEC) upon oxidation of the phenol. DFT calculations and IRSEC results demonstrate that with sufficiently strong electron-donating groups at the para-position of the N-phenylimine group (e.g., -OCH3 substitution), proton transfer to the imine is exergonic upon phenol oxidation, leading to a one-electron, two-proton (E2PT) product with the imidazole acting as a proton relay. When transfer of the second proton is not sufficiently exergonic (e.g., -CN substitution), a one-electron, one-proton transfer (EPT) product is dominant. Thus, the extent of proton translocation along the H-bond network, either ~1.6 Å or ~6.4 Å, can be controlled through imine substitution. Moreover, the H-bond strength between the benzimidazole NH and the imine nitrogen, which is a function of their relative pKa values, and the redox potential of the phenoxyl radical/phenol couple are linearly correlated with the Hammett constants of the substituents. In all cases, a high potential (~1 V vs SCE) is observed for the phenoxyl radical/phenol couple. Designing and tuning redox-coupled proton wires is important for understanding bioenergetics and developing novel artificial photosynthetic systems.Fil: Odella, Emmanuel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Arizona State University; Estados Unidos. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; ArgentinaFil: Mora, Sabrina Jimena. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Arizona State University; Estados UnidosFil: Wadsworth, Brian L.. Arizona State University; Estados UnidosFil: Huynh, Mioy T.. University of Yale; Estados UnidosFil: Goings, Joshua J.. University of Yale; Estados UnidosFil: Liddell, Paul A.. Arizona State University; Estados UnidosFil: Groy, Thomas L.. Arizona State University; Estados UnidosFil: Gervaldo, Miguel Andres. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; ArgentinaFil: Sereno, Leonides Edmundo. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; ArgentinaFil: Gust, Devens. Arizona State University; Estados UnidosFil: Moore, Thomas A.. Arizona State University; Estados UnidosFil: Moore, Gary F.. Arizona State University; Estados UnidosFil: Hammes-Schiffer, Sharon. University of Yale; Estados UnidosFil: Moore, Ana L.. Arizona State University; Estados Unido