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2020
Bernardo, M, Correa CR, Ringelspacher Y, Becker GC, Lapa N, Fonseca I, Esteves IAAC, Kruse A.  2020.  Porous carbons derived from hydrothermally treated biogas digestate. Waste Management. 105:170-179. AbstractWebsite

Porous carbons from digestate-derived hydrochar were produced, characterized and their performance to reclaim phosphate from water was evaluated as a preliminary approach to demonstrate their practical application. In a first step, the digestate was converted into hydrochars through hydrothermal carbonization by using two different pH conditions: 8.3 (native conditions) and 3.0 (addition of H2SO4). The resulting hydrochars did not present significant differences. Consecutively, the hydrochars were activated with KOH to produce activated carbons with enhanced textural properties. The resulting porous carbons presented marked differences: the AC native presented a lower ash content (20.3 wt%) and a higher surface area (SBET = 1106 m2/g) when compared with the AC-H2SO4 (ash content = 43.7 wt% SBET = 503 m2/g). Phosphorus, as phosphate, is a resource present in significative amount in wastewater, causing serious problems of eutrophication. Therefore, the performance of the porous carbons samples to recover phosphate – P(PO43−) – from water was evaluated through exploitation assays that included kinetic studies. The lumped model presented a good fitting to the kinetic data and the obtained uptake capacities were the same for both carbons, 12 mg P(PO43−)/g carbon. Despite the poorer textural properties of AC-H2SO4, this carbon was richer in Ca, Al, Fe, K, and Mg cations which promoted the formation of mineral complexes with phosphate anions. The results obtained in this work are promising for the future development of P(PO43−) enriched carbons that can be used thereafter as biofertilizers in soil amendment applications.

Godino-Ojer, M, Blazquez-García R, Matos I, Bernardo M, Fonseca IM, Pérez Mayoral E.  2020.  Porous carbons-derived from vegetal biomass in the synthesis of quinoxalines. Mechanistic insights. Catalysis Today. 354:90-99. AbstractWebsite

We report herein for the first-time acid biomass-derived carbons from vegetal biomass, with high developed porosity, prepared through integrating method comprising pyrolysis and surface phosphonation, able to efficiently catalyze the synthesis of quinoxalines from 1,2-diamines and α-hydroxi ketones, under aerobic conditions. The obtained results indicate that the reaction is mainly driven by a combination of acid function strength and textural properties in terms of conversion and selectivity. Furthermore, our experimental and theoretical observations suggest that the preferred reaction pathway for this transformation, in the presence of the investigated acid carbon catalysts, involves cascade reactions including imination reaction between reactants, successive imine-enamine and keto-enol tautomerisms, heterocyclization followed by dehydration, and aromatization. While the acid sites seem to be a relevant role in each reaction step, the system formed by activated carbon and molecular oxygen could be behind the last oxidative reaction to give the corresponding nitrogen heterocycles.

Agostinho, DAS, Paninho AI, Cordeiro T, Nunes AVM, Fonseca IM, Pereira C, Matias A, Ventura MG.  2020.  Properties of κ-carrageenan aerogels prepared by using different dissolution media and its application as drug delivery systems. Materials Chemistry and Physics. 253:123290. AbstractWebsite

This work reports the synthesis of kappa-carrageenan aerogels using different dissolution and crosslinking media in order to evaluate its effects on the textural properties of the matrixes and further on the drug loading and release performance. The different aerogel samples were produced through the dissolution of the biopolymer in water with addition of potassium salts as crosslinking agents and, in two different ionic liquids (ILs) derived from imidazolium ion, being further dried with supercritical CO2. The samples were characterized by Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR), Scanning Electron Microscopy (SEM), Nitrogen Adsorption-Desorption Analysis, Thermogravimetry (TGA) and Differential Scanning Calorimetry (DSC). The synthesized samples presented surface areas similar to the carrageenan aerogels being their structure constituted mainly by meso and macropores. The absence of ionic liquid in samples was demonstrated by DSC analysis and was corroborated by the cytotoxicity assays which revealed that cellular viability in Caco-2 cells was preserved. Tetracycline was used as a model drug and loaded in two of the prepared aerogels samples. The release experiments were performed with the composites to test in vitro drug release at physiologic pH. With a higher macroporosity, the kappa-carrageenan aerogel prepared by dissolution into ionic liquid showed a higher loading capacity than the one prepared by dissolution into water and a slightly higher release rate. The matrixes were considered to present a good potential to be used as biocompatible carriers on drug controlled delivery.

Baptista, {PV}.  2020.  RNA Quantification Using Noble Metal Nanoprobes: Simultaneous Identification of Several Different mRNA Targets Using Color Multiplexing and Application to Chronic Myeloid Leukemia Diagnostics. Nanoparticles in Biology and Medicine. (E. Ferrari, M. Soloviev, Eds.).:251–268., United States: Humana Press Abstract

Nanotechnology provides new tools for gene expression analysis that allow for sensitive and specific characterization of prognostic signatures related to cancer. Cancer is a complex disease where multiple gene loci contribute to the phenotype. The ability to simultaneously monitor differential expression originating from each locus allows for a more accurate indication into the degree of cancerous activity than either locus alone. Metal nanoparticles have been widely used as labels for in vitro identification and quantification of target sequences. Here we describe the synthesis of nanoparticles with different noble metal compositions in an alloy format that are then functionalized with thiol-modified ssDNA (nanoprobes). We also show how such nanoprobes are used in a non-cross-linking colorimetric method for the direct detection and quantification of specific mRNA targets, without the need for enzymatic amplification or reverse-transcription steps. The different metals in the alloy provide for distinct absorption spectra due to their characteristic plasmon resonance peaks. The color multiplexing allows for simultaneous identification of different mRNA targets involved in cancer development. A comparison of the absorption spectra of the nanoprobe mixtures taken before and after induced aggregation of metal nanoparticles allows to both identify and quantify each mRNA target. We describe the use of gold and gold–silver alloy nanoprobes for the development of the non-cross-linking method to detect a specific BCR-ABL fusion gene (e.g., e1a2 and e14a2) mRNA target associated with chronic myeloid leukemia (CML) using 10 ng/μL of unamplified total human RNA. Additionally, we demonstrate the use of this approach for the direct diagnostics of CML. This simple methodology takes less than 50 min to complete after total RNA extraction with comparable specificity and sensitivity to the more commonly used methods.

Alves-Barroco, C, Paquete-Ferreira J, Santos-Silva T, Fernandes AR.  2020.  Singularities of Pyogenic Streptococcal Biofilms – From Formation to Health Implication. Frontiers in Microbiology. 11:3179. AbstractWebsite

Biofilms are generally defined as communities of cells involved in a self-produced extracellular matrix adhered to a surface. In biofilms, the bacteria are less sensitive to host defense mechanisms and antimicrobial agents, due to multiple strategies, that involve modulation of gene expression, controlled metabolic rate, intercellular communication, composition, and 3D architecture of the extracellular matrix. These factors play a key role in streptococci pathogenesis, contributing to therapy failure and promoting persistent infections. The species of the pyogenic group together with Streptococcus pneumoniae are the major pathogens belonging the genus Streptococcus, and its biofilm growth has been investigated, but insights in the genetic origin of biofilm formation are limited. This review summarizes pyogenic streptococci biofilms with details on constitution, formation, and virulence factors associated with formation.

Ferreira, MR, Fernandes TM, Salgueiro CA.  2020.  Thermodynamic properties of triheme cytochrome PpcF from Geobacter metallireducens reveal unprecedented functional mechanism. Biochimica et Biophysica Acta (BBA) - Bioenergetics. 1861:148271., Number 11 AbstractWebsite

The bacterium Geobacter metallireducens is highly efficient in long-range extracellular electron transfer, a process that relies on an efficient bridging between the cytoplasmic electron donors and the extracellular acceptors. The periplasmic triheme cytochromes are crucial players in these processes and thus the understanding of their functional mechanism is crucial to elucidate the extracellular electron transfer processes in this microorganism. The triheme cytochrome PpcF from G. metallireducens has the lowest amino acid sequence identity with the remaining cytochromes from the PpcA-family of G. sulfurreducens and G. metallireducens, making it an interesting target for structural and functional studies. In this work, we performed a detailed functional and thermodynamic characterization of cytochrome PpcF by the complementary usage of NMR and visible spectroscopic techniques. The results obtained show that the heme reduction potentials are negative, different from each other and are also modulated by the redox and redox-Bohr interactions that assure unprecedented mechanistic features to the protein. The results showed that the order of oxidation of the hemes in cytochrome PpcF is maintained in the entire physiological pH range. The considerable separation of the hemes' redox potential values facilitates a sequential transfer within the chain of redox centers in PpcF, thus assuring electron transfer directionality to the electron acceptors.

2019
Echeverria, C, Almeida PL, Figueirinhas JL, Godinho MH.  2019.  Understanding the influence of carbon nanotubes on the flow behavior of liquid crystalline hydroxypropylcellulose: A Rheo-NMR study, {OCT 10}. POLYMER. 180:121675. AbstractWebsite

Hydroxypropylcellulose (HPC) is an important cellulose derivative that has been widely studied due to its water-solubility, biocompatibility and biodegradability, but even more significant due to its ability to form liquid crystalline phases. HPC is able to form, under certain conditions, chiral nematic (cholesteric) structures in water solutions. Previous work confirmed that films prepared from liquid crystalline HPC/water solutions (LC-HPC) gave rise to anisotropic networks, with similar mechanical and optical characteristics of Liquid Crystalline Elastomers (LCE), capable to respond to humidity. It was also demonstrated that the incorporation of carbon nanotubes (CNTs) significantly improved the actuator responsiveness. In the work presented herein, we investigate how the incorporation of carbon nanotubes affects the flow behavior of LC-HPC solutions, and thus the structure-properties relationship, through a detailed Rheo-NMR study. As observed from the results, when shearing the samples, the degree of order reached (maximum quadrupolar peak splitting) by LC-HPC solutions increases with CNT content. Regarding the subsequent relaxation process, only the incorporation of 0.01 wt% of CNTs (lowest content) contributes to a faster recovery of cholesteric structure.

Almeida, J, Roma-Rodrigues C, Mahmoud {AG }, {Guedes da Silva} F{MC }, Pombeiro {AJL }, Martins {LMDRS }, Baptista {PV}, Fernandes {AR}.  2019.  Structural characterization and biological properties of silver(I) tris(pyrazolyl)methane sulfonate, oct. Journal of Inorganic Biochemistry. 199: Elsevier Abstract

The water-soluble 1D helical coordination polymer [Ag(Tpms)]n (1) [Tpms = tris(pyrazolyl)methane sulfonate, −O3SC(pz)3; pz = pyrazolyl] was synthesized and fully characterized, its single-crystal X-ray diffraction analysis revealing the ligand acting as a bridging chelate N3-donor ligand. The antiproliferative potential of 1 was performed on two human tumour cell lines, A2780 and HCT116, and in normal fibroblasts, with a much higher effect in the former cell line (IC50 of 0.04 μM) as compared to the latter cell line and to normal fibroblasts. Compound 1 does not alter cell cycle progression but interferes with the adherence of A2780 cells triggering cell apoptosis. Apoptosis appears to occur via the extrinsic pathway (no changes in mitochondria membrane potential, reactive oxygen species (ROS) and pro-apoptotic (B-cell lymphoma 2 (BCL-2) associated protein (BAX))/anti-apoptotic (BCL-2) ratio) being this hypothesis also supported by the presence of silver mainly in the supernatants of A2780 cells. Results also indicated that cell death via autophagy was triggered. Proteomic analysis allowed us to confirm that compound 1 is able to induce a stress response in A2780 cells that is related with its antiproliferative activity and the trigger of apoptosis.

Sutradhar, M, Alegria {ECBA }, Ferretti F, Raposo {LR }, {Guedes da Silva} F{MC }, Baptista {PV}, Fernandes {AR}, Pombeiro {AJL }.  2019.  Antiproliferative activity of heterometallic sodium and potassium-dioxidovanadium(V) polymers, nov. Journal of Inorganic Biochemistry. 200: Elsevier Abstract

The syntheses of the heterometallic sodium and potassium-dioxidovanadium 2D polymers, [NaVO2(1κNOO’;2κO”-L)(H2O)]n (1) and [KVO2(1κNOO’;2κO’;3κO”-L)(EtOH)]n (2) (where the κ notation indicates the coordinating atoms of the polydentate ligand L) derived from (3,5-di-tert-butyl-2-hydroxybenzylidene)-2-hydroxybenzohydrazide (H2L) are reported. The polymers were characterized by IR, NMR, elemental analysis and single crystal X-ray diffraction analysis. The antiproliferative potential of 1 and 2 was examined towards four human cancer cell lines (ovarian carcinoma, A2780, colorectal carcinoma, HCT116, prostate carcinoma, PC3 and breast adenocarcinoma, MCF-7cell lines) and normal human fibroblasts. Complex 1 and 2 showed the highest cytotoxic activity against A2780 cell line (IC50 8.2 and 11.3 μM, respectively) with 1 > 2 and an IC50 in the same range as cisplatin (IC50 3.4 μM; obtained in the same experimental conditions) but, interestingly, with no cytotoxicity to healthy human fibroblasts for concentrations up to 75 μM. This high cytotoxicity of 1 in ovarian cancer cells and its low cytotoxicity in healthy cells demonstrates its potential for further biological studies. Our results suggest that both complexes induce ovarian carcinoma cell death via apoptosis and autophagy, but autophagy is the main biological cause of the reduction of viability observed and that ROS (reactive oxygen species) may play an important role in triggering cell death.

Pedrosa, P, Corvo L}{M, Ferreira-Silva M, Martins P, Carvalheiro {MC}, Costa {PM }, Martins C, Martins {LMDRS, Baptista {PV}, Fernandes {AR}.  2019.  Targeting cancer resistance via multifunctional gold nanoparticles, nov. International Journal of Molecular Sciences. 20, Number 21: MDPI - Multidisciplinary Digital Publishing Institute Abstract

Resistance to chemotherapy is a major problem facing current cancer therapy, which is continuously aiming at the development of new compounds that are capable of tackling tumors that developed resistance toward common chemotherapeutic agents, such as doxorubicin (DOX). Alongside the development of new generations of compounds, nanotechnology-based delivery strategies can significantly improve the in vivo drug stability and target specificity for overcoming drug resistance. In this study, multifunctional gold nanoparticles (AuNP) have been used as a nanoplatform for the targeted delivery of an original anticancer agent, a Zn(II) coordination compound [Zn(DION)2]Cl2 (ZnD), toward better efficacy against DOX-resistant colorectal carcinoma cells (HCT116 DR). Selective delivery of the ZnD nanosystem to cancer cells was achieved by active targeting via cetuximab, NanoZnD, which significantly inhibited cell proliferation and triggered the death of resistant tumor cells, thus improving efficacy. In vivo studies in a colorectal DOX-resistant model corroborated the capability of NanoZnD for the selective targeting of cancer cells, leading to a reduction of tumor growth without systemic toxicity. This approach highlights the potential of gold nanoformulations for the targeting of drug-resistant cancer cells.

Santos, {MM }, Raposo {LR }, c}alo Carrera {G{\cVSM }, Costa A, Dionísio M, Baptista {PV}, Fernandes {AR}, Branco {LC }.  2019.  Ionic Liquids and Salts from Ibuprofen as Promising Innovative Formulations of an Old Drug, may. Chemmedchem. 14, Number 9: John Wiley & Sons, Ltd. Abstract

Herein we report the synthesis of novel ionic liquids (ILs) and organic salts by combining ibuprofen as anion with ammonium, imidazolium, or pyridinium cations. The methodology consists of an acid–base reaction of neutral ibuprofen with cation hydroxides, which were previously prepared by anion exchange from the corresponding halide salts with Amberlyst A-26(OH). In comparison with the parent drug, these organic salts display higher solubility in water and biological fluids and a smaller degree of polymorphism, which in some cases was completely eliminated. With the exception of [C 16 Pyr][Ibu] and [N 1,1,2,2OH1 ][Ibu], the prepared salts did not affect the viability of normal human dermal fibroblasts or ovarian carcinoma (A2780) cells. Therefore, these ibuprofen-based ionic liquids may be very promising lead candidates for the development of effective formulations of this drug.

Rodrigo, {AP }, Martins C, Tanoeiro L, Casaca M, Lopes {AR }, Parola {AJ }, Matos {AP }, Baptista {PV }, Fernandes {AR }, Costa {PM }.  2019.  New lessons from ancient life: marine invertebrates as a source of new drugs, mar. Annals of Medicine. 51:S45–S46., Number Suppl.1: Taylor & Francis Abstract
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Veigas, B, Matias A, Calmeiro T, Fortunato E, Fernandes {AR}, Baptista {PV}.  2019.  Antibody modified gold nanoparticles for fast colorimetric screening of rheumatoid arthritis, jun. Analyst. 144:3613–3619., Number 11: RSC - Royal Society of Chemistry Abstract

Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by chronic joint inflammation and one of the main causes of chronic disability worldwide with high prevalence in the ageing population. RA is characterized by autoantibody production, synovial inflammation and bone destruction, and the most accepted biomarker is rheumatoid factor (RF) autoantibodies. In this work, we developed a low-cost approach for the detection and quantification of the RF marker. This colorimetric immunosensor is based on gold nanoprobe crosslinking that results in extensive aggregation in the presence of the pentameric IgM RF. Aggregation of the nanoconjugates yields a color change from red to purple that can be easily observed by the naked eye. The interaction between nanoconjugates and the specific target was confirmed via dynamic light scattering (DLS), Raman spectroscopy and atomic force microscopy (AFM) imaging. This conceptual system shows a LOD of 4.15 UA mL-1 IgM RF (clinical threshold is set for 20 IU mL-1). The one-step biosensor strategy herein proposed is much faster than conventional detection techniques, without the need for secondary antibodies, additional complex washing or signal amplification protocols. To the best of our knowledge this is the first report on target induced aggregation of gold nanoprobes for quantitative colorimetric autoantibody detection.

Kourmentza, C, Araújo D, Sevrin C, Roma-Rodriques C, Ferreira {JL}, Freitas F, Dionisio M, Baptista {PV}, Fernandes {AR}, Grandfils C, Reis {MAM }.  2019.  Occurrence of non-toxic bioemulsifiers during polyhydroxyalkanoate production by Pseudomonas strains valorizing crude glycerol by-product, jun. Bioresource Technology. 281:31–40.: Elsevier Abstract

While screening for polyhydroxyalkanoate (PHA) producing strains, using glycerol rich by-product as carbon source, it was observed that extracellular polymers were also secreted into the culture broth. The scope of this study was to characterize both intracellular and extracellular polymers, produced by Pseudomonas putida NRRL B-14875 and Pseudomonas chlororaphis DSM 50083, mostly focusing on those novel extracellular polymers. It was found that they fall into the class of bioemulsifiers (BE), as they showed excellent emulsion stability against different hydrocarbons/oils at various pH conditions, temperature and salinity concentrations. Cytotoxicity tests revealed that BE produced by P. chlororaphis inhibited the growth of highly pigmented human melanoma cells (MNT-1) by 50% at concentrations between 150 and 200 μg/mL, while no effect was observed on normal skin primary keratinocytes and melanocytes. This is the first study reporting mcl-PHA production by P. putida NRRL B-14785 and bioemulsifier production from both P. putida and P. chlororaphis strains.

Roque, ACA, Fred A, Gamboa H.  2019.  Foreword, January 2019. BIODEVICES 2019 - 12th International Conference on Biomedical Electronics and Devices, Proceedings; Part of 12th International Joint Conference on Biomedical Engineering Systems and Technologies, BIOSTEC 2019. , Prague: SciTePress
Carvalho, LCR, Lourenco A, Ferreira LM, Branco PS.  2019.  Tofacitinib Synthesis - An Asymmetric Challenge, JAN 31. EUROPEAN JOURNAL OF ORGANIC CHEMISTRY. 2019:615-624., Number 4 Abstract

Tofacitinib is a Janus activated kinase (JAK) inhibitor approved for the treatment of rheumatoid arthritis and active psoriatic arthritis. Its synthesis normally involves long synthetic sequences due to the chirality associated to the piperidine ring. This review is a comprehensive analysis of the different synthetic methods used to prepare this active pharmaceutical ingredient (API), covering the related journal and patent literature.

Roma-Rodrigues, C, Mendes R, Baptista {PV}, Fernandes {AR}.  2019.  Targeting Tumor Microenvironment for Cancer Therapy, feb. International Journal of Molecular Sciences. 20, Number 4: MDPI - Multidisciplinary Digital Publishing Institute Abstract

Cancer development is highly associated to the physiological state of the tumor microenvironment (TME). Despite the existing heterogeneity of tumors from the same or from different anatomical locations, common features can be found in the TME maturation of epithelial-derived tumors. Genetic alterations in tumor cells result in hyperplasia, uncontrolled growth, resistance to apoptosis, and metabolic shift towards anaerobic glycolysis (Warburg effect). These events create hypoxia, oxidative stress and acidosis within the TME triggering an adjustment of the extracellular matrix (ECM), a response from neighbor stromal cells (e.g., fibroblasts) and immune cells (lymphocytes and macrophages), inducing angiogenesis and, ultimately, resulting in metastasis. Exosomes secreted by TME cells are central players in all these events. The TME profile is preponderant on prognosis and impacts efficacy of anti-cancer therapies. Hence, a big effort has been made to develop new therapeutic strategies towards a more efficient targeting of TME. These efforts focus on: (i) therapeutic strategies targeting TME components, extending from conventional therapeutics, to combined therapies and nanomedicines; and (ii) the development of models that accurately resemble the TME for bench investigations, including tumor-tissue explants, {"}tumor on a chip{"} or multicellular tumor-spheroids.

Oliveira, H, Roma-Rodrigues C, Santos A, Veigas B, Brás N, Faria A, c}ão Calhau C{\c, {de Freitas} V, Baptista {PV}, Mateus N, Fernandes {AR}, Fernandes I.  2019.  GLUT1 and GLUT3 involvement in anthocyanin gastric transport- Nanobased targeted approach, dec. Scientific Reports. 9, Number 1: Nature Publishing Group Abstract

Anthocyanins may protect against a myriad of human diseases. However few studies have been conducted to evaluate their bioavailability so their absorption mechanism remains unclear. This study aimed to evaluate the role of two glucose transporters (GLUT1 and GLUT3) in anthocyanins absorption in the human gastric epithelial cells (MKN-28) by using gold nanoparticles to silence these transporters. Anthocyanins were purified from purple fleshed sweet potatoes and grape skin. Silencing of GLUT1 and/or GLUT3 mRNA was performed by adding AuNP@GLUT1 and/or AuNP@GLUT3 to MKN-28 cells. Downregulation of mRNA expression occurred concomitantly with the reduction in protein expression. Malvidin-3-O-glucoside (Mv3glc) transport was reduced in the presence of either AuNP@GLUT1 and AuNP@GLUT3, and when both transporters were blocked simultaneously. Peonidin-3-(6′-hydroxybenzoyl)-sophoroside-5-glucoside (Pn3HBsoph5glc) and Peonidin-3-(6′-hydroxybenzoyl-6″-caffeoyl)-sophoroside-5-glucoside (Pn3HBCsoph5glc) were assayed to verify the effect of the sugar moiety esterification at glucose B in transporter binding. Both pigments were transported with a lower transport efficiency compared to Mv3glc, probably due to steric hindrance of the more complex structures. Interestingly, for Pn3HBCsoph5glc although the only free glucose is at C5 and the inhibitory effect of the nanoparticles was also observed, reinforcing the importance of glucose on the transport regardless of its position or substitution pattern. The results support the involvement of GLUT1 and GLUT3 in the gastric absorption of anthocyanins.

Marques, A, Veigas B, Araújo A, Pagará B, Baptista {PV}, Águas H, Martins R, Fortunato E.  2019.  Paper-Based SERS Platform for One-Step Screening of Tetracycline in Milk, dec. Scientific Reports. 9, Number 1: Nature Publishing Group Abstract

Throughout the last decade, the expansion of food testing has been gradually moving towards ordinary high throughput screening methods performed on-site. The demand for point-of-care testing, able to distinguish molecular signatures with high accuracy, sensitivity and specificity has been significantly increasing. This new requirement relies on the on-site detection and monitorization of molecular signatures suitable for the surveillance of food production and processing. The widespread use of antibiotics has contributed to disease control of livestock but has also created problems for the dairy industry and consumers. Its therapeutic and subtherapeutic use has increased the risk of contamination in milk in enough concentrations to cause economic losses to the dairy industry and have a health impact in highly sensitive individuals. This study focuses on the development of a simple Surface-Enhanced Raman Spectroscopy (SERS) method for fast high throughput screening of tetracycline (TET) in milk. For this, we integrate a paper-based low-cost, fully recyclable and highly stable SERS platform, with a minimal sample preparation protocol. A two-microliter sample of milk solutions spiked with TET (from 0.01 to 1000 ppm) is dried on a silver nanoparticle coated cardboard substrate and measured via a Raman spectrophotometer. The SERS substrate showed to be extremely stable with a shelf life of several months. A global spectrum principal component analysis approach was used to test all the detected vibrational modes and their correlation with TET concentration. Peak intensity ratios (455 cm−1/1280 cm−1 and 874 cm−1/1397 cm−1) were found to be correlated with TET concentrations in milk, achieving a sensitivity as low as 0.1 ppm. Results indicate that this SERS method combined with portable Raman spectrometer is a potential tool that can be used on-site for the monitoring of TET residues and other antibiotics.

Roma-Rodrigues, C, Pombo I, Raposo L, Pedrosa P, Fernandes {AR}, Baptista {PV}.  2019.  Nanotheranostics Targeting the Tumor Microenvironment, aug. Frontiers in Bioengineering and Biotechnology. 7:197.: Frontiers Media Abstract

Cancer is considered the most aggressive malignancy to humans, and definitely the major cause of death worldwide. Despite the different and heterogenous presentation of the disease, there are pivotal cell elements involved in proliferation, differentiation, and immortalization, and ultimately the capability to evade treatment strategies. This is of utmost relevance when we are just beginning to grasp the complexity of the tumor environment and the molecular {"}evolution{"} within. The tumor micro-environment (TME) is thought to provide for differentiation niches for clonal development that results in tremendous cancer heterogeneity. To date, conventional cancer therapeutic strategies against cancer are failing to tackle the intricate interplay of actors within the TME. Nanomedicine has been proposing innovative strategies to tackle this TME and the cancer cells that simultaneously provide for biodistribution and/or assessment of action. These nanotheranostics systems are usually multi-functional nanosystems capable to carry and deliver active cargo to the site of interest and provide diagnostics capability, enabling early detection, and destruction of cancer cells in a more selective way. Some of the most promising multifunctional nanosystems are based on gold nanoparticles, whose physic-chemical properties have prompt for the development of multifunctional, responsive nanomedicines suitable for combinatory therapy and theranostics. Herein, we shall focus on the recent developments relying on the properties of gold nanoparticles as the basis for nanotheranostics systems against the heterogeneity within the TME.

Godinho, D, Nogueira M, Bernardo M, Dias D, Lapa N, Fonseca I, Pinto F.  2019.  Recovery of Cr(III) by using chars from the co-gasification of agriculture and forestry wastes, Aug. Environmental Science and Pollution Research. 26:22723–22735., Number 22 AbstractWebsite

The aim of the present work was to assess the efficiency of biochars obtained from the co-gasification of blends of rice huskþinspace}+þinspace}corn cob (biochar 50CC) and rice huskþinspace}+þinspace}eucalyptus stumps (biochar 50ES), as potential renewable low-cost adsorbents for Cr(III) recovery from wastewaters. The two gasification biochars presented a weak porous structure (ABETþinspace}=þinspace}63–144 m2 g−1), but a strong alkaline character, promoted by a high content of mineral matter (59.8{%} w/w of ashes for 50CC biochar and 81.9{%} w/w for 50ES biochar). The biochars were used for Cr(III) recovery from synthetic solutions by varying the initial pH value (3, 4, and 5), liquid/solid (L/S) ratio (100–500 mL g−1), contact time (1–120 h), and initial Cr(III) concentration (10–150 mg L−1). High Cr(III) removal percentages (around 100{%}) were obtained for both biochars, due to Cr precipitation, at low L/S ratios (100 and 200 mL g−1), for the initial pH 5 and initial Cr concentration of 50 mg L−1. Under the experimental conditions in which other removal mechanisms rather than precipitation occurred, a higher removal percentage (49.9{%}) and the highest uptake capacity (6.87 mg g−1) were registered for 50CC biochar. In the equilibrium, 50ES biochar presented a Cr(III) removal percentage of 27{%} with a maximum uptake capacity of 2.58 mg g−1. The better performance on Cr(III) recovery for the biochar 50CC was attributed to its better textural properties, as well as its higher cation exchange capacity.

Peixoto, D, Malta G, Cruz H, Barroso S, Carvalho AL, Ferreira LM, Branco PS.  2019.  N-Heterocyclic Olefin Catalysis for the Ring Opening of Cyclic Amidine Compounds: A Pathway to the Synthesis of c-Caprolactamand -Lactam-Derived Amines, APR 5. JOURNAL OF ORGANIC CHEMISTRY. 84:3793-3800., Number 7 Abstract
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Jesus, {AR }, Soromenho {MRC }, Raposo {LR }, Esperan{\c c}a {JMSS }, Baptista {PV}, Fernandes {AR}, Reis {PM }.  2019.  Enhancement of water solubility of poorly water-soluble drugs by new biocompatible N-acetyl amino acid N-alkyl cholinium-based ionic liquids, apr. European Journal of Pharmaceutics and Biopharmaceutics. 137:227–232.: Elsevier Science B.V., Amsterdam. Abstract

The major challenge of the pharmaceutical industry is to find potential solvents for poorly water-soluble drug molecules. Ionic liquids (ILs) have attracted this industry as (co-) solvents due to their unique physicochemical and biological properties. Herein, a straightforward approach for the enhancement of water solubility of paracetamol and sodium diclofenac is presented, using new biocompatible N-acetyl amino acid N-alkyl cholinium-based ionic liquids as co-solvents (0.2 - 1 mol%). These new ionic liquids were able to increase water solubility of these drugs up to four times higher than in pure water or in an inorganic salt solution. In the presence of these ILs the drugs lipophilicity (log Kow) was not significantly changed for paracetamol, but for sodium diclofenac it was possible to decrease significantly its lipophilicity. Concerning cytotoxicity in human dermal fibroblasts it was observed that ILs did not show a significant toxicity, and were able to improve cell viability compared with the respective precursors.

Das, K, Datta A, Massera C, Roma-Rodrigues C, Barroso M, Baptista {PV}, Fernandes {AR}.  2019.  Structural aspects of a trimetallic Cu II derivative: cytotoxicity and anti-proliferative activity on human cancer cell lines, apr. Journal of Coordination Chemistry. 72:920–940., Number 5-7: Taylor & Francis Abstract

A trimetallic Cu II derivative, [Cu 3 (L) 2 (CF 3 COO) 2 ] (1) (where H 2 L = N,N′-bis(salicylidene)-1,3-propanediamine), was prepared and characterized. In 1, the two terminal Cu II ions are linked to the central Cu II by trifluoroacetato and doubly bridging phenoxido. Both the square-pyramidal and octahedral geometries are observed among two different Cu II centers in the linear arrangement of the trimetallic unit. Compound 1 is characterized by IR and UV-Vis spectra. Compound 1 has high cytotoxic activity in breast adenocarcinoma (MCF-7), colorectal carcinoma (HCT116) and particularly, in ovarian carcinoma (A2780) cell line compared to a lung adenocarcinoma cell line. The IC 50 in A2780 cells is 25 times lower than the respective value for normal human primary fibroblasts demonstrating 1 has higher cytotoxicity towards cancer cells. Additionally, combination of DOX with 1 induces a higher loss of HCT116 cell viability compared with each drug alone.

Veigas, B, Matias A, Calmeiro T, Fortunato E, Fernandes AR, Baptista PV.  2019.  Antibody modified gold nanoparticles for fast colorimetric screening of rheumatoid arthritis, 2019. Analyst. 144(11):3613-3619. AbstractWebsite

Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by chronic joint inflammation and one of the main causes of chronic disability worldwide with high prevalence in the ageing population. RA is characterized by autoantibody production, synovial inflammation and bone destruction, and the most accepted biomarker is rheumatoid factor (RF) autoantibodies. In this work, we developed a low-cost approach for the detection and quantification of the RF marker. This colorimetric immunosensor is based on gold nanoprobe crosslinking that results in extensive aggregation in the presence of the pentameric IgM RF. Aggregation of the nanoconjugates yields a color change from red to purple that can be easily observed by the naked eye. The interaction between nanoconjugates and the specific target was confirmed via dynamic light scattering (DLS), Raman spectroscopy and atomic force microscopy (AFM) imaging. This conceptual system shows a LOD of 4.15 UA mL(-1) IgM RF (clinical threshold is set for 20 IU mL(-1)). The one-step biosensor strategy herein proposed is much faster than conventional detection techniques, without the need for secondary antibodies, additional complex washing or signal amplification protocols. To the best of our knowledge this is the first report on target induced aggregation of gold nanoprobes for quantitative colorimetric autoantibody detection.