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Mourtas S.,University of Patras | Lazar A.N.,Laboratoire Of Neuropathologie Escourolle | Lazar A.N.,French Institute of Health and Medical Research | Markoutsa E.,University of Patras | And 4 more authors.
European Journal of Medicinal Chemistry | Year: 2014

With the objective to formulate multifunctional nanosized liposomes to target amyloid deposits in Alzheimer Disease (AD) brains, a lipid-PEG-curcumin derivative was synthesized and characterized. Multifunctional liposomes incorporating the curcumin derivative and additionally decorated with a Blood Brain Barrier (BBB) transport mediator (anti-Transferin antibody) were prepared and characterized. The fluorescence intensity of curcumin derivative was found to increase notably when the curcumin moiety was in the form of a diisopropylethylamine (DIPEA) salt. Both curcumin-derivative liposomes and curcumin-derivative Anti-TrF liposomes showed a high affinity for the amyloid deposits, on post-mortem brains samples of AD patients. The ability of both liposomes to delay Aβ1-42 peptide aggregation was confirmed by Thioflavin assay. However, the decoration of the curcumin-derivative liposomes with the Anti-TrF improved significantly the intake by the BBB cellular model. Results verify that the attachment of an antibody on the curcumin-liposome surface does not block deposit staining or prevention of Aβ aggregation, while the presence of the curcumin-PEG-lipid conjugate does not reduce their brain-targeting capability substantially, proving the potential of such multifunctional NLs for application in Alzheimer disease treatment and diagnosis. © 2014 Elsevier Masson SAS. All rights reserved. Source

Trump E.R.,Carnegie Mellon University | Fountoukis C.,Institute of Chemical Engineering science | Donahue N.M.,Carnegie Mellon University | Pandis S.N.,Carnegie Mellon University | Pandis S.N.,University of Patras
Atmospheric Environment | Year: 2015

Atmospheric chemical transport models (CTMs) have often serious difficulties reproducing the observed aerosol nitrate levels. We hypothesize that one of the reasons for these errors is their treatment of the competition between the accumulation and coarse-mode particles for the condensing nitric acid. The hybrid mass transfer method is used in the CTM PMCAMx to test this hypothesis. The simulation approach combines the dynamic calculation of mass transfer to coarse-mode particles while maintaining computational efficiency by assuming that the fine mode particles are in equilibrium. The resulting model is applied to Europe and evaluated for the period of May 2008 against ground-based and airborne Aerosol Mass Spectrometer measurements from the EUCAARI campaign.PMCAMx using the default equilibrium approach to calculate the partitioning of semi-volatile PM components between the gas and particle phases seriously overpredicts PM1 nitrate levels especially for locations in which there were relatively high coarse-mode particle concentrations (significant sea-salt or dust concentrations). This shortcoming was especially apparent for the Mace Head site in Ireland, where a large amount of nitrate was associated with sea-salt. The improved simulation of the coarse-mode particle chemistry results in significant improvement of the predictions of PM1 nitrate and ammonium. Sea-salt emissions in areas with high nitric acid levels reduce the PM1 nitrate concentrations. © 2014 Elsevier Ltd. Source

Antonopoulou G.,Institute of Chemical Engineering science | Lyberatos G.,National Technical University of Athens
Waste and Biomass Valorization | Year: 2013

In this work, the effect of pretreatment on the biochemical methane potential (BMP) of sweet sorghum biomass was determined. Various pretreatment methods, such as thermal (1 h at 121 °C), enzymatic [through the addition of the enzyme Celluclast 1.5L (Cellulase from Trichoderma reesei , ATCC 26921) or by the addition of a mixture of Celluclast 1.5L and Novozyme 188 (Cellobiase from Aspergillus niger) at a ratio of (3:1)], chemical [through alkali (NaOH) or acid (H2SO4) addition, at concentrations of 0-2% w/v] or combination of the above methods (thermal acid and thermal alkaline) were tested, in order to evaluate their effect on carbohydrate solubilization (saccharification) and on the methane yield. The experimental results showed that thermal acid treatment and enzymatic treatment for all enzymes concentrations tested improved saccharification. Under thermal alkaline treatment at NaOH concentrations above 0.5% w/v, a significant decrease in soluble carbohydrates concentration was observed meaning that a high portion of sugars also contained in sorghum biomass was degraded or was transformed into other components. BMP experiments showed that the chemical pretreatment methods did not enhance methane generation compared to the raw substrates. This could be attributed either to inhibitory compounds released during pretreatment, or to high salts (cations of sodium during alkaline treatment) concentration, causing in both cases methanogenic bacteria inhibition. On the other hand, thermal treatment improved the methane yield from 253 to 288 LCH4/kg sorghum. During enzymatic pretreatment, the methane production was enhanced either with only one or with the mixture of enzymes. © Springer Science+Business Media 2012. Source

Tremouli A.,University of Patras | Antonopoulou G.,University of Patras | Antonopoulou G.,Institute of Chemical Engineering science | Bebelis S.,University of Patras | And 2 more authors.
Bioresource Technology | Year: 2013

Electricity production from filter sterilized cheese whey at different organic loads (0.35, 0.7, 1.5, 2.7 and 6.7gCOD/L respectively) was investigated in a two-chamber microbial fuel cell (MFC). The best performance of the cell was observed at the highest concentration of the pretreated (filter sterilized) cheese whey (6.7gCOD/L) corresponding to a maximum power density of approximately 46mW/m2. Experiments using glucose (0.35gCOD/L) were also performed for comparison reasons. The study of the open-circuit impedance characteristics of the MFC and of the individual electrodes revealed that the open-circuit impedance of the MFC depended to practically the same extent on both the ohmic resistance between the anode and cathode and the overall polarization resistance. The polarization resistance of the MFC decreased significantly under closed-circuit conditions, which in turn implies that the ohmic overpotential is the main contribution to the energy losses in two-chamber MFCs. © 2013 Elsevier Ltd. Source

Popescu M.-T.,University of Patras | Tsitsilianis C.,University of Patras | Tsitsilianis C.,Institute of Chemical Engineering science
ACS Macro Letters | Year: 2013

The present study reports on the development of composite gold nanoparticles (AuNPs)/polymersome formulations, based on pH-responsive biocompatible polymer vesicles integrating prefunctionalized AuNPs, doped with a hydrophobic model probe for improved multimodal drug delivery. The polymer vesicles were prepared from an amphiphilic pentablock terpolymer poly(ε-caprolactone)-b-poly(ethylene oxide)-b-poly(2-vinylpyridine)-b- poly(ethylene oxide)-b-poly(ε-caprolactone) (PCL-PEO-P2VP-PEO-PCL), consisting of a pH-sensitive and biodegradable P2VP/PCL membrane, surrounded by neutral hydrophilic PEO looping chains. Additionally, partial quaternization of the P2VP block has been performed to introduce cationic moieties. Water-dispersible AuNPs carrying a hydrophobic molecule were encapsulated in the hydrophilic aqueous lumen of the vesicles, and the release was monitored at pH conditions simulating physiological and tumor environments. The complex delivery of the cargos from these vesicles showed improved and controlled kinetics relative to the individual nanocarriers, which could be further tuned by pH and chemical modification of the membrane forming block. © 2013 American Chemical Society. Source

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