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2020
Restani, {RB }, Tavares {MT }, Pires {RF }, Baptista {PV}, Fernandes {AR}, Casimiro T, Bonifácio {VDB }, Aguiar-Ricardo A.  2020.  Correction to: Nano-in-Micro Sildenafil Dry Powder Formulations for the Treatment of Pulmonary Arterial Hypertension Disorders: The Synergic Effect of POxylated Polyurea Dendrimers, PLGA, and Cholesterol (Part. Part. Syst. Charact, (2020), 37, (1900447), , nov. Particle and Particle Systems Characterization. 37, Number 11: Wiley-VCH Verlag Abstract

Part. Part. Syst. Charact. 2020, 37, 1900447 In the originally published manuscript, the author Márcia T. Tavares was omitted. The author is hereby added in the author byline and is associated with the first affiliation.

Mendes, MJ.  2020.  Colloidal lithography for transparent electronics and light trapping in thin film flexible solar cells, 3-4 Nov.. Encontro Ciência 2020. , Lisbon, Portugal: Fundação para a Ciência e a Tecnologia
Ferreira, P, Cerqueira NSMFA, Fernandes PA, Romão MJ, Ramos MJ.  2020.  Catalytic Mechanism of Human Aldehyde Oxidase, 2020. ACS CatalysisACS Catalysis. 10(16):9276-9286.: American Chemical Society AbstractWebsite

The mechanism of oxidation of N-heterocycle phthalazine to phthalazin-1(2H)-one and its associated free energy profile, catalyzed by human aldehyde oxidase (hAOX1), was studied in atomistic detail using QM/MM methodologies. The studied reaction was found to involve three sequential steps: (i) protonation of the substrate’s N2 atom by Lys893, (ii) nucleophilic attack of the hydroxyl group of the molybdenum cofactor (Moco) to the substrate, and (iii) hydride transfer from the substrate to the sulfur atom of the Moco. The free energy profile that was calculated revealed that the rate-limiting step corresponds to hydride transfer. It was also found that Lys893 plays a relevant role in the reaction, being important not only for the anchorage of the substrate close to the Moco, but also in the catalytic reaction. The variations of the oxidation state of the molybdenum ion throughout the catalytic cycle were examined too. We found out that during the displacement of the products away from the Moco, the transfer of electrons from the catalytic site to the FAD site was proton-coupled. As a consequence, the most favorable and fastest pathway for the enzyme to complete its catalytic cycle was that with MoV and a deprotonated SH ligand of the Moco with the FAD molecule converted to its semiquinone form, FADH•.The mechanism of oxidation of N-heterocycle phthalazine to phthalazin-1(2H)-one and its associated free energy profile, catalyzed by human aldehyde oxidase (hAOX1), was studied in atomistic detail using QM/MM methodologies. The studied reaction was found to involve three sequential steps: (i) protonation of the substrate’s N2 atom by Lys893, (ii) nucleophilic attack of the hydroxyl group of the molybdenum cofactor (Moco) to the substrate, and (iii) hydride transfer from the substrate to the sulfur atom of the Moco. The free energy profile that was calculated revealed that the rate-limiting step corresponds to hydride transfer. It was also found that Lys893 plays a relevant role in the reaction, being important not only for the anchorage of the substrate close to the Moco, but also in the catalytic reaction. The variations of the oxidation state of the molybdenum ion throughout the catalytic cycle were examined too. We found out that during the displacement of the products away from the Moco, the transfer of electrons from the catalytic site to the FAD site was proton-coupled. As a consequence, the most favorable and fastest pathway for the enzyme to complete its catalytic cycle was that with MoV and a deprotonated SH ligand of the Moco with the FAD molecule converted to its semiquinone form, FADH•.

Lima, N, Baptista AC, Faustino BMM, Taborda S, Marques A, Ferreira I.  2020.  Carbon threads sweat-based supercapacitors for electronic textiles. Scientific Reports. 10:7703. AbstractWebsite

Flexible and stretchable energy-storage batteries and supercapacitors suitable for wearable electronics are at the forefront of the emerging field of intelligent textiles. In this context, the work here presented reports on the development of a symmetrical wire-based supercapacitor able to use the wearer’s sweat as the electrolyte. The inner and outer electrodes consists of a carbon-based thread functionalized with a conductive polymer (polypyrrole) which improves the electrochemical performances of the supercapacitor. The inner electrode is coated with electrospun cellulose acetate fibres, as the separator, and the outer electrode is twisted around it. The electrochemical performances of carbon-based supercapacitors were analyzed using a simulated sweat solution and displayed a specific capacitance of 2.3 F.g−1, an energy of 386.5 mWh.kg−1 and a power density of 46.4 kW.kg−1. Moreover, cycle stability and bendability studies were performed. Such energy conversion device has exhibited a stable electrochemical performance under mechanical deformation, over than 1000 cycles, which make it attractive for wearable electronics. Finally, four devices were tested by combining two supercapacitors in series with two in parallel demonstrating the ability to power a LED.

Lima, N, Baptista AC, Faustino BMM, Taborda S, Marques A, Ferreira I.  2020.  Carbon threads sweat-based supercapacitors for electronic textiles. Scientific reports. 10:1-9.
Perdigão, P, Faustino B, Faria J, Canejo JP, Borges JB, Ferreira I, Baptista AC.  2020.  Conductive Electrospun Polyaniline/Polyvinylpyrrolidone Nanofibers: Electrical and Morphological Characterization of New Yarns for Electronic Textiles. Fibers. 8(4):24. AbstractWebsite

Advanced functionalities textiles embedding electronic fibers, yarns and fabrics are a demand for innovative smart cloths. Conductive electrospun membranes and yarns based on polyaniline/polyvinylpyrrolidone (PANI/PVP) were investigated using the chemical modification of PANI instead of using conventional coating processes as in-situ polymerization. PANI was synthesized from the aniline monomer and the influence of the oxidant-to-monomer ratio on electrical conductivity was studied. The optimized conductivity of pellets made with pressed PANI powders was 21 S·cm−1. Yarns were then prepared from the t-Boc-PANI/PVP electrospun membranes followed by PANI protonation to enhance their electrical properties. Using this methodology, electrospun membranes and yarns were produced with electrical conductivities of 1.7 × 10−2 and 4.1 × 10−4 S·cm−1.

Perdigão, P, Faustino BM, Faria J, Canejo JP, Borges JP, Ferreira I, Baptista AC.  2020.  Conductive electrospun polyaniline/polyvinylpyrrolidone nanofibers: Electrical and morphological characterization of new yarns for electronic textiles. Fibers. 8:24.
Adeoye, O, Conceição J, Serra PA, da Silva AB, Duarte N, Guedes RC, Corvo MC, Aguiar-Ricardo A, Jicsinszky L, Casimiro T, Cabral-Marques H.  2020.  Cyclodextrin solubilization and complexation of antiretroviral drug lopinavir: In silico prediction; Effects of derivatization, molar ratio and preparation method. Carbohydrate Polymers. 227:115287.: Elsevier AbstractWebsite

Lopinavir (LPV) is currently used in combination with ritonavir for the clinical management of HIV infections due to its limited oral bioavailability. Herein, we report the application of an in silico method to study cyclodextrin (CyD) host-guest molecular interaction with LPV for the rational selection of the best CyD for developing a CyD based LPV delivery system. The predicted CyD, a (2-hydroxy)propyl-gamma derivative with high degree of substitution (HP17-γ-CyD) was synthesized and comparatively evaluated with γ-CyD and the commercially available HP-γ-CyD. All complexes were prepared by supercritical assisted spray drying (SASD) and co-evaporation (CoEva) at molar ratios (1:1 and 1:2); and afterwards fully characterized. Results indicate a higher LPV amorphization and solubilization ability of HP17-γ-CyD. The SASD processing technology also enhanced LPV solubilization and release from complexes. The application of in silico methodologies is a feasible approach for the rational and/or deductive development of CyD drug delivery systems.

2019
Choroba, K, Machura B, Kula S, Raposo LR, Fernandes AR, Kruszynski R, Erfurt K, Shul'pina LS, Kozlov YN, Shul'pin GB.  2019.  Copper(ii) complexes with 2,2':6',2''-terpyridine, 2,6-di(thiazol-2-yl)pyridine and 2,6-di(pyrazin-2-yl)pyridine substituted with quinolines. Synthesis, structure, antiproliferative activity, and catalytic activity in the oxidation of alkanes and alcohols, 2019. Dalton Trans. 48(33):12656-12673. AbstractWebsite

A series of 2,2':6',2''-terpyridine (terpy), 2,6-di(thiazol-2-yl)pyridine (dtpy) and 2,6-di(pyrazin-2-yl)pyridine (dppy) derivatives with n-quinolyl substituents (n = 2 and 4) was used to synthesize five-coordinate complexes [CuCl2(n-quinolyl-terpy)] (1-2), [CuCl2(n-quinolyl-dtpy)] (3-4) and [CuCl2(n-quinolyl-dppy)] (5-6), respectively. The main emphasis of the research was to investigate the impact of the triimine skeleton (terpy, dtpy and dppy) and n-quinolyl pendant substituent on the antiproliferative and catalytic properties of 1-6. The obtained Cu(ii) compounds were studied as antiproliferative agents against human colorectal (HCT116) and ovarian (A2780) carcinoma, and they were used as catalysts for the oxidation of alkanes and alcohols with peroxides under mild conditions. The kinetic characteristics of the oxidizing species generated by the catalytic system Cu(ii) complex-H2O2 in CH3CN were obtained from the dependence of the alkane oxidation rate on its initial concentration. A model of competitive interaction of hydroxyl radicals with CH3CN and RH in the catalyst cavity has been proposed which is based on the simultaneous study of kinetics and selectivity in alkane oxidations.

Roma-Rodrigues, C, Fernandes AR, Baptista PV.  2019.  Counteracting the effect of leukemia exosomes by antiangiogenic gold nanoparticles, 2019. Int J Nanomedicine. 14:6843-6854. AbstractWebsite

Purpose: Progression of chronic myeloid leukemia (CML) is frequently associated with increased angiogenesis at the bone marrow mediated by exosomes. The capability of gold nanoparticles (AuNPs) functionalized with antiangiogenic peptides to hinder the formation of new blood vessels has been demonstrated in a chorioallantoic membrane (CAM) model. Methods: Exosomes of K562 CML cell line were isolated and their angiogenic effect assessed in a CAM model. AuNPs functionalized with antiangiogenic peptides were used to block the angiogenic effect of CML-derived exosomes, assessed by evaluation of expression levels of key modulators involved in angiogenic pathways - VEGFA, VEGFR1 (also known as FLT1) and IL8. Results: Exosomes isolated from K562 cells promoted the doubling of newly formed vessels associated with the increase of VEGFR1 expression. This is a concentration and time-dependent effect. The AuNPs functionalized with antiangiogenic peptides were capable to block the angiogenic effect by modulating VEGFR1 associated pathway. Conclusion: Exosomes derived from blast cells are capable to trigger (neo)-angiogenesis, a key factor for the progression and spreading of cancer, in particular in CML. AuNPs functionalized with specific antiangiogenic peptides are capable to block the effect of the exosomes produced by malignant cells via modulation of the intrinsic VEGFR pathway. Together, these data highlight the potential of nanomedicine-based strategies against cancer proliferation.

Santos, Â, Otero V, Vilarigues M.  2019.  Characterisation of glass and painting materials from 18th century hand-painted glass slides used for projection with Magic Lanterns. Interim Meeting of the ICOM-CC Glass and Ceramics Working Group − "Recent Advances in Glass and Ceramics Conservation 2019". :219-224., London, England, 5-7 September 2019 AbstractSantos et al (2019) ICOM-CC_GlassCeramics.pdf

With the invention of the Magic Lantern during the 17th century, new perspectives for the pre-cinema universe started to emerge. During the following two centuries, this instrument achieved extraordinary success on all social media.
One of the first stages of the production of glass slides for projection with magic lanterns was the hand-painting technique that nowadays represents a significant challenge for conservation professionals due to the diversity of painting materials used and their exposure to aggressive conditions during the projections.
A set of Italian 18th-century hand-painted glass slides from the Cinemateca Portuguesa – Museu do Cinema's collection are currently being studied. The glass was characterised using Energy Dispersive X-Ray Fluorescence Spectrometry (µ-EDXRF) and the identification of the painting materials was performed by Fourier Transform Infrared Spectroscopy (µ-FTIR) and Raman Spectroscopy (µ-Raman). Further investigation will be conducted with Optical Microscopy (OM), UV-Vis Fibre-Optic Reflectance Spectroscopy (FORS), and Microspectrofluorimetry.
The combination of different analytical techniques on glass slides examples allowed us to identify the composition of the glass and paintings materials, as well as to determine their current state of preservation.

Almeida, APC, Canejo JP, Almeida PL, Godinho MH.  2019.  Cholesteric-type cellulosic structures: from plants to applications. Liquid Crystals. :accepted.Website
Szymczak, P, Rau MH, Monteiro JM, Pinho MG, Filipe SR, Vogensen FK, Zeidan AA, Janzen T.  2019.  A comparative genomics approach for identifying host-range determinants in Streptococcus thermophilus bacteriophages. Scientific Reports. 9(1):7991.
Machado, MA, Antin K-N, Rosado LS, Vilaça P, Santos TG.  2019.  Contactless high-speed eddy current inspection of unidirectional carbon fiber reinforced polymer. Composites Part B: Engineering. 168:226-235. AbstractWebsite

This paper presents the development and the results of a customized eddy current (EC) non-destructive testing (NDT) system for highly demanding online inspection conditions. Several planar eddy current array probes were designed, numerically simulated and experimentally compared for the inspection of low conductivity unidirectional carbon fibre reinforced polymer (CFRP) ropes. The inspections were performed using a dedicated scanner device at 4 m/s with 3 mm probe lift-off where defects under 1 mm were detected with an excellent SNR. Different defect morphologies and sizes, such as broken fibres and lateral cuts, were successful detected and compared to conventional probes.

Zanatta, M, Simon NM, dos Santos FP, Corvo MC, Cabrita EJ, Dupont J.  2019.  Correspondence on “Preorganization and Cooperation for Highly Efficient and Reversible Capture of Low-Concentration CO2 by Ionic Liquids”. Angewandte Chemie International Edition. AbstractWebsite

The preorganization and cooperation mechanism of imide‐based ionic liquids reported in a recent Communication was evocated to rationalize the extremely high gravimetric CO2 capture displayed by these fluids. An analysis of the reported spectroscopic evidences together with additional experiments led to the proposition of an alternative, simpler, and feasible mechanism involving the formation of bicarbonate.

Mileusnić, M, et al.  2019.  Croatian geological heritage related to historical mining and quarrying. European Geologist Journal. (48):5-9.
Cristovão, AF, Sousa D, Silvestre F, Ropio I, Gaspar A, Henriques C, Velhinho A, Baptista AC, Faustino M, Ferreira I.  2019.  Customized tracheal design using 3D printing of a polymer hydrogel: influence of UV laser cross-linking on mechanical properties. 3D Print Med. 5:12.
Cristovão, AF, Sousa D, Silvestre F, Ropio I, Gaspar A, Henriques C, Velhinho A, Baptista AC, Faustino M, Ferreira I.  2019.  Customized tracheal design using 3D printing of a polymer hydrogel: influence of UV laser cross-linking on mechanical properties. 3D Printing in Medicine. 5:12. AbstractWebsite

Background
The use of 3D printing of hydrogels as a cell support in bio-printing of cartilage, organs and tissue has attracted much research interest. For cartilage applications, hydrogels as soft materials must show some degree of rigidity, which can be achieved by photo- or chemical polymerization. In this work, we combined chemical and UV laser polymeric cross-linkage to control the mechanical properties of 3D printed hydrogel blends. Since there are few studies on UV laser cross-linking combined with 3D printing of hydrogels, the work here reported offered many challenges.

Methods
Polyethylene glycol diacrylate (PEGDA), sodium alginate (SA) and calcium sulphate (CaSO4) polymer paste containing riboflavin (vitamin B2) and triethanolamine (TEOHA) as a biocompatible photoinitiator was printed in an extrusion 3D plotter using a coupled UV laser. The influence of the laser power on the mechanical properties of the printed samples was then examined in unconfined compression stress-strain tests of 1 × 1 × 1 cm3 sized samples. To evaluate the adhesion of the material between printed layers, compression measurements were performed along the parallel and perpendicular directions to the printing lines.

Results
At a laser density of 70 mW/cm2, Young’s modulus was approximately 6 MPa up to a maximum compression of 20% in the elastic regime for both the parallel and perpendicular measurements. These values were within the range of biological cartilage values. Cytotoxicity tests performed with Vero cells confirmed the cytocompatibility.

Conclusions
We printed a partial tracheal model using optimized printing conditions and proved that the materials and methods developed may be useful for printing of organ models to support surgery or even to produce customized tracheal implants, after further optimization.

Nogueira, M, Matos I, Bernardo M, Pinto F, Lapa N, Surra E, Fonseca I.  2019.  Char from Spent Tire Rubber: A Potential Adsorbent of Remazol Yellow Dye. C—Journal of Carbon Research. 5, Number 4 AbstractWebsite

A char produced from spent tire rubber showed very promising results as an adsorbent of Remazol Yellow (RY) from aqueous solutions. Spent tire rubber was submitted to a pyrolysis process optimized for char production. The obtained char was submitted to chemical, physical, and textural characterizations and, subsequently, applied as a low-cost adsorbent for dye (RY) removal in batch adsorption assays. The obtained char was characterized by relatively high ash content (12.9% wt), high fixed-carbon content (69.7% wt), a surface area of 69 m2/g, and total pore volume of 0.14 cm3/g. Remazol Yellow kinetic assays and modelling of the experimental data using the pseudo-first and pseudo-second order kinetic models demonstrated a better adjustment to the pseudo-first order model with a calculated uptake capacity of 14.2 mg RY/g char. From the equilibrium assays, the adsorption isotherm was fitted to both Langmuir and Freundlich models; it was found a better fit for the Langmuir model to the experimental data, indicating a monolayer adsorption process with a monolayer uptake capacity of 11.9 mg RY/g char. Under the experimental conditions of the adsorption assays, the char presented positive charges at its surface, able to attract the deprotonated sulfonate groups (SO3−) of RY; therefore, electrostatic attraction was considered the most plausible mechanism for dye removal.

Torrisi, G, Luis JS, Sanchez-Sobrado O, Raciti R, Mendes MJ, Águas H, Fortunato E, Martins R, Terrasi A.  2019.  Colloidal-structured metallic micro-grids: High performance transparent electrodes in the red and infrared range. Solar Energy Materials and Solar Cells. 197:7-12. AbstractWebsite

One of the most promising approaches to produce industrial-compatible Transparent Conducting Materials (TCMs) with excellent characteristics is the fabrication of TCO/metal/TCO multilayers. In this article, we report on the electro-optical properties of a novel high-performing TCO/metal/TCO structure in which the intra-layer is a micro-structured metallic grid instead of a continuous thin film. The grid is obtained by evaporation of Ag through a mask of polystyrene colloidal micro-spheres deposited by the Langmuir-Blodgett method and partially dry-etched in plasma. IZO/Ag grid/IZO structures with different thicknesses and mesh dimensions have been fabricated, exhibiting excellent electrical characteristics (sheet resistance below 10 Ω/□) and particularly high optical transmittance in the near-infrared spectral region as compared to planar (unstructured) TCM multilayers. Numerical simulations were also used to highlight the role of the Ag mesh parameters on the electrical properties.

Roma-Rodrigues, C, Fernandes {AR}, Baptista {PV}.  2019.  Counteracting the effect of leukemia exosomes by antiangiogenic gold nanoparticles. International journal of nanomedicine. 14:6843–6854.: Dove Medical Press Abstract

Purpose: Progression of chronic myeloid leukemia (CML) is frequently associated with increased angiogenesis at the bone marrow mediated by exosomes. The capability of gold nanoparticles (AuNPs) functionalized with antiangiogenic peptides to hinder the formation of new blood vessels has been demonstrated in a chorioallantoic membrane (CAM) model. Methods: Exosomes of K562 CML cell line were isolated and their angiogenic effect assessed in a CAM model. AuNPs functionalized with antiangiogenic peptides were used to block the angiogenic effect of CML-derived exosomes, assessed by evaluation of expression levels of key modulators involved in angiogenic pathways - VEGFA, VEGFR1 (also known as FLT1) and IL8. Results: Exosomes isolated from K562 cells promoted the doubling of newly formed vessels associated with the increase of VEGFR1 expression. This is a concentration and timedependent effect. The AuNPs functionalized with antiangiogenic peptides were capable to block the angiogenic effect by modulating VEGFR1 associated pathway. Conclusion: Exosomes derived from blast cells are capable to trigger (neo)-angiogenesis, a key factor for the progression and spreading of cancer, in particular in CML. AuNPs functionalized with specific antiangiogenic peptides are capable to block the effect of the exosomes produced by malignant cells via modulation of the intrinsic VEGFR pathway. Together, these data highlight the potential of nanomedicine-based strategies against cancer proliferation.

Tulcidas, A, Lourenço NMT, Antunes R, Santos B, Pawlowski S, Rocha F.  2019.  Crystal habit modification and polymorphic stability assessment of a long-acting β2-adrenergic agonist. CrystEngComm. 21:3460-3470.: The Royal Society of Chemistry AbstractWebsite

Properties such as particle orientation{,} flowability{,} packing{,} compaction{,} syringeability{,} suspension stability and dissolution are the most influenced by changes in the crystal habit and polymorphic form of a drug substance. The crystal habit of a drug substance (long-acting β2-adrenergic agonist (LABA)){,} as well as its purity and polymorphic stability{,} was studied after performing slurry tests with 1{,}2-dimethoxyethane : heptane solution at 50 °C. In these slurry tests{,} the product was kept suspended and undissolved{,} with agitation{,} for polymorphic conversion evaluation. Since no significant modifications were observed in the crystal shape and dimensions at 50 °C{,} a new slurry test was performed at a temperature above the melting point of the starting material (80 °C). In the latter test{,} it was possible to obtain crystals with increased dimensions by 480% compared with the starting material. Additionally{,} the desired polymorphic form (form I) was obtained as well as an acceptable purity of approximately 99%. These are promising results{,} not only for downstream purposes{,} but also concerning the bioavailability of the drug substance. This work shows that working at a temperature higher than the melting point of the compound seems to modify the crystal habit of the product.

2018
Almeida, APC, Canejo JP, Fernandes SN, Echeverria C, Almeida PL, Godinho MH.  2018.  Cellulose-{{Based Biomimetics}} and {{Their Applications}}, may. Advanced Materials. 30:1703655., Number 19 Abstract
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Pedrosa, P, Mendes R, Cabral R, Martins {LMDRS }, Baptista {PV}, Fernandes {AR}.  2018.  Combination of chemotherapy and Au-nanoparticle photothermy in the visible light to tackle doxorubicin resistance in cancer cells, dec. Scientific Reports. 8, Number 1: Nature Publishing Group Abstract

Despite great advances in the fight against cancer, traditional chemotherapy has been hindered by the dose dependent adverse side effects that reduce the usable doses for effective therapy. This has been associated to drug resistance in tumor cells that often cause relapse and therapy failure. These drawbacks have been tackled by combining different therapeutic regiments that prevent drug resistance while decreasing the chemotherapy dose required for efficacious ablation of cancer. In fact, new metallic compounds have been in a continuous development to extend the existing chemotherapy arsenal for these combined regimens. Here, we demonstrate that combination of a metallic compound (TS265), previously characterized by our group, with photothermy circumvents cells resistant to Doxorubicin (DOX). We first engendered a colorectal carcinoma cell line (HCT116) highly resistant to DOX, whose viability was diminished after administration of TS265. Cancer cell death was potentiated by challenging these cells with 14 nm spherical gold nanoparticles followed by laser irradiation at 532 nm. The combination of TS265 with photothermy lead to 65% cell death of the DOX resistant cells without impacting healthy cells. These results support the use of combined chemotherapy and photothermy in the visible spectrum as an efficient tool for drug resistant tumors.