Publications

Abstract Amitriptyline (AMT) frequent presence in environmental waters reflects the continuous consumption growth and raises issues on the importance of its monitorization. In this work, a sensitive and selective electrochemiluminescence (ECL) sensor was constructed using molecularly imprinted polymer (MIP) recognition element for AMT detection. Molecular dynamics (MD) simulations were performed to select the best functional monomer. Precipitation polymerization was followed to prepare the MIP micro spheres using methacrylic acid (MAA) as functional monomer, ethylene glycol methacrylate (EGDMA) as crosslinker and chloroform (CHL) as solvent. The MIP sensor was then prepared on a low cost and disposable screen-printed electrodes (SPCEs), previously modified with single-walled carbon nanotubes (SWCNTs), by drop coating a solution containing the MIP microspheres synthesized. The mechanism of detection was based in the system Ru(bpy)(3)(2+)/AMT, where AMT acts as co-reactor of Ru(bpy)(3)(2+) ECL. Several parameters controlling the preparation process of the sensor and AMT detection were optimised. The MIP/SWCNTs/SPCE ECL sensor showed good analytical performance with a linear correlation between ECL signal and the AMT concentration ranging from 0.1 to 200 mu M (R-2 = 0.9991). The limits of detection (LOD) and quantification (LOQ) were found to be 0.4 mu M (S/N = 3) and 1.5 mu M (S/N = 10), respectively. The MIP ECL sensor displayed good selectivity to recognise AMT molecules when compared with analoge structures and it was successfully applied in real water samples with good recovery values (90 to 112%). The developed MIP ECL sensor is suitable for integration with portable devices for AMT detection in environmental waters.

Abstract 2.3. Cell culture conditions Skin fibroblasts from five sporadic late-onset PD (sPD) male patients and five age- and sex-matched healthy controls were obtained from a cell line repository of the Coriell Institute for Medical Research, USA (www.coriell.org), and their detailed information was previously described [43]. The repository ID numbers of control fibroblasts used were: ND29178, ND29179, ND34770, ND35044, and ND38530; the repository ID numbers of sPD fibroblasts used were: ND34265, ND35320, ND35322, ND35976, and ND39999.

Abstract A combination of several pharmacophores in one molecule has been successfully used for multi-target-directed ligands (MTDL) design. New propargylamine substituted derivatives combined with salicylic and cinnamic scaffolds were designed and synthesized as potential cholinesterases and monoamine oxidases (MAOs) inhibitors. They were evaluated in vitro for inhibition of acetyl- (AChE) and butyrylcholinesterase (BuChE) using Ellman's method. All the compounds act as dual inhibitors. Most of the derivatives are stronger inhibitors of AChE, the best activity showed 5-bromo-N-(prop-2-yn-1-yl)salicylamide 1e (IC50 = 8.05 mu M). Carbamates (4-bromo-2[(prop-2-yn-1-yl)carbamoyl]phenyl ethyl(methyl)carbamate 2d and 2,4-dibromo-6-[(prop-2-yn-1-yl)carbamoyl] phenyl ethyl(methyl)carbamate 2e were selective and the most active for BuChE (25.10 and 26.09 mu M). 4-Bromo2-[(prop-2-yn-1-ylimino)methyl]phenol 4a was the most potent inhibitor of MAOs (IC50 of 3.95 and approximate to 10 mu M for MAO-B and MAO-A, respectively) along with a balanced inhibition of both cholinesterases being a real MTDL. The mechanism of action was proposed, and binding modes of the hits were studied by molecular docking on human enzymes. Some of the derivatives also exhibited antioxidant properties. In silico prediction of physicochemical parameters affirm that the molecules would be active after oral administration and able to reach brain tissue.

Abstract Mobile handheld devices, such as smartphones and tablets, have become some of the most prominent ubiquitous terminals within the information and communication technology landscape. Their transformative power within the digital music domain changed the music ecosystem from production to distribution and consumption. Of interest here is the ever-expanding number of mobile music applications. Despite their growing popularity, their design in terms of interaction perception and control is highly arbitrary. It remains poorly addressed in related literature and lacks a clear, systematized approach. In this context, our paper aims to provide the first steps towards defining guidelines for optimal sonic interaction design practices in mobile music applications. Our design approach is informed by user data in appropriating mobile handheld devices. We conducted an experiment to learn links between control gestures and musical parameters, such as pitch, duration, and amplitude. A twofold action-reflection protocol and tool-set for evaluating the aforementioned links-are also proposed. The results collected from the experiment show statistically significant trends in pitch and duration control gesture mappings. On the other hand, amplitude appears to elicit a more diverse mapping approach, showing no definitive trend in this experiment.

Abstract Non-alcoholic steatohepatitis (NASH), one of the deleterious stages of non-alcoholic fatty liver disease, remains a significant cause of liver-related morbidity and mortality worldwide. In the current work, we used an exploratory data analysis to investigate time-dependent cellular and mitochondrial effects of different supra-physiological fatty acids (FA) overload strategies, in the presence or absence of fructose (F), on human hepatoma-derived HepG2 cells. We measured intracellular neutral lipid content and reactive oxygen species (ROS) levels, mitochondrial respiration and morphology, and caspases activity and cell death. FA-treatments induced a time-dependent increase in neutral lipid content, which was paralleled by an increase in ROS. Fructose, by itself, did not increase intracellular lipid content nor aggravated the effects of palmitic acid (PA) or free fatty acids mixture (FFA), although it led to an up-expression of hepatic fructokinase. Instead, F decreased mitochondrial phospholipid content, as well as OXPHOS subunits levels. Increased lipid accumulation and ROS in FA-treatments preceded mitochondrial dysfunction, comprising altered mitochondrial membrane potential (Delta psi m) and morphology, and decreased oxygen consumption rates, especially with PA. Consequently, supra-physiological PA alone or combined with F prompted the activation of caspase pathways leading to a time-dependent decrease in cell viability. Exploratory data analysis methods support this conclusion by clearly identifying the effects of FA treatments. In fact, unsupervised learning algorithms created homogeneous and cohesive clusters, with a clear separation between PA and FFA treated samples to identify a minimal subset of critical mitochondrial markers in order to attain a feasible model to predict cell death in NAFLD or for high throughput screening of possible therapeutic agents, with particular focus in measuring mitochondrial function.

Abstract <jats:p>The progression of non-alcoholic fatty liver (NAFL) into non-alcoholic steatohepatitis implicates multiple mechanisms, chief of which is mitochondrial dysfunction. However, the sequence of events underlying mitochondrial failure are still poorly clarified. In this work, male C57BL/6J mice were fed with a high-fat plus high-sucrose diet for 16, 20, 22, and 24 weeks to induce NAFL. Up to the 20th week, an early mitochondrial remodeling with increased OXPHOS subunits levels and higher mitochondrial respiration occurred. Interestingly, a progressive loss of mitochondrial respiration along “Western diet” feeding was identified, accompanied by higher susceptibility to mitochondrial permeability transition pore opening. Importantly, our findings prove that mitochondrial alterations and subsequent impairment are independent of an excessive mitochondrial reactive oxygen species (ROS) generation, which was found to be progressively diminished along with disease progression. Instead, increased peroxisomal abundance and peroxisomal fatty acid oxidation-related pathway suggest that peroxisomes may contribute to hepatic ROS generation and oxidative damage, which may accelerate hepatic injury and disease progression. We show here for the first time the sequential events of mitochondrial alterations involved in non-alcoholic fatty liver disease (NAFLD) progression and demonstrate that mitochondrial ROS are not one of the first hits that cause NAFLD progression.</jats:p>

Abstract 4-Oxoquinoline derivatives have been often used in drug discovery programs due to their pharmacological properties. Inspired on chromone and 4-oxoquinoline chemical structure similarity, a small series of quinoline-based compounds was obtained and screened, for the first time, toward human monoamine oxidases isoforms. The data showed the N-(3,4-dichlorophenyl)-1-methyl-4-oxo-1,4-dihydroquinoline-3-carboxamide 10 was the most potent and selective MAO-B inhibitor (IC50 = 5.30 +/- 0.74 nM and SI: >= 1887). The data analysis showed that prototropic tautomerism markedly influences the biological activity. The unequivocal characterisation of the quinoline tautomers was performed to understand the attained data. To our knowledge, there have been no prior reports on the characterisation of quinolone tautomers by 2D NMR techniques, namely by H-1-N-15 HSQC and H-1-N-15 HMBC, which are proposed as expedite tools for medicinal chemistry campaigns. Computational studies on enzyme-ligand complexes, obtained after MM-GBSA calculations and molecular dynamics simulations, supported the experimental data.

Abstract Chromone-3-phenylcarboxamides (Crom-1 and Crom-2) were identified as potent, selective, and reversible inhibitors of human monoamine oxidase B (hMAO-B). Since they exhibit some absorption, distribution, metabolism, and excretion (ADME)-toxicity liabilities, new derivatives were synthesized to map the chemical structural features that compose the pharmacophore, a process vital for lead optimization. Structure-activity relationship data, supported by molecular docking studies, provided a rationale for the contribution of the heterocycle's rigidity, the carbonyl group, and the benzopyran heteroatom for hMAO-B inhibitory activity. From the study, N-(3-chlorophenyl)-4H-thiochromone-3-carboxamide (31) (hMAO-B IC50 = 1.52 +/- 0.15 nM) emerged as a reversible tight binding inhibitor with an improved pharmacological profile. In in vitro ADME-toxicity studies, compound 31 showed a safe cytotoxicity profile in Caco-2, SH-SY5Y, HUVEC, HEK-293, and MCF-7 cells, did not present cardiotoxic effects, and did not affect P-gp transport activity. Compound 31 also protected SH-SY5Y cells from iron(III)-induced damage. Collectively, these studies highlighted compound 31 as the first-in-class and a suitable candidate for in vivo preclinical investigation.

Abstract Molecularly imprinted materials have been used in selective photocatalysis, essentially due to surface properties, possibility of reuse and low cost, that enhance their industrial and economic interest. The molecular imprinting technique allows the development of photocatalysts with selective recognition for a template molecule, used during synthesis, by increasing the surface area caused by selective recognition sites for the template used. In this work the preparation of hollow titania microspheres was merged with the process of generating selectivity for bilirubin in the shell structure by molecular imprinting. Three major synthesis parameters (solvent, temperature and TiO2 precursor) were studied by performing a set of experiments based in a full factorial design. The selected synthesis conditions were mainly dictated by the maximization of the surface area normalized by the thickness of the TiO2 shell and its controllability. The microspheres kept the integrity of the spherical shape while dispersed in the synthesis solvent. The observed imprinting features for the hollow microspheres prepared in the final synthesis conditions included imprinting factors of 3.1 for the binding strength and 1.3 for the capacity, and bilirubin/protoporphirin selectivity factors of 4.0 in terms of binding strength and 9.6 in terms of binding capacity. These features are very promising, especially the high selectivity factors, given the high resemblance between bilirubin and protoporphirin, and also due to the threat that the somewhat aggressive treatment for the silica core removal, might eventually pose to the templated microstructure of the shell. In fact, the photocatalytic selectivity of the imprinted microspheres was confirmed, with the observation of up to two-fold faster rates of bilirubin consumption vs. protoporphyrin consumption. © 2020

Abstract Two immunosensors were advanced to target hazelnut Cor a 14 based on electrochemical and optical transduction. Both approaches were developed with two types of custom-made antibodies, namely anti-Cor a 14 IgG (rabbit) and anti-Cor a 14 IgY (hen's egg) targeting the Cor a 14 allergen. Antibody immobilisation was performed via EDC/NHS onto disposable screen-printed electrodes. The detection limit (LOD) of the electrochemical immunoassay for Cor a 14 was 5-times lower than the optical, being down to 0.05 fg mL-1 with a dynamic range of 0.1 fg mL-1 to 0.01 ng mL-1. Antibody selectivity was verified against non-target 2S albumins (potential crossreactive plant species). Anti-Cor a 14 IgY exhibited the best specificity, presenting minor cross-reactivity with peanut/walnut. Preliminary results of the application of anti-Cor a 14 IgY electrochemical immunosensor to incurred foods established a LOD of 1 mg kg- 1 of hazelnut in wheat (0.16 mg kg- 1 hazelnut protein).