Brás, JLA, Pinheiro BA, Cameron K, Cuskin F, Viegas A, Najmudin S, Bule P, Pires VMR, Romão MJ, Bayer EA, Spencer HL, Smith S, Gilbert HJ, Alves VD, Carvalho AL, Fontes CMGA.
2016.
Diverse specificity of cellulosome attachment to the bacterial cell surface, dec. Scientific Reports. 6:38292.: The Author(s)
AbstractDuring the course of evolution, the cellulosome, one of Nature's most intricate multi-enzyme complexes, has been continuously fine-tuned to efficiently deconstruct recalcitrant carbohydrates. To facilitate the uptake of released sugars, anaerobic bacteria use highly ordered protein-protein interactions to recruit these nanomachines to the cell surface. Dockerin modules located within a non-catalytic macromolecular scaffold, whose primary role is to assemble cellulosomal enzymatic subunits, bind cohesin modules of cell envelope proteins, thereby anchoring the cellulosome onto the bacterial cell. Here we have elucidated the unique molecular mechanisms used by anaerobic bacteria for cellulosome cellular attachment. The structure and biochemical analysis of five cohesin-dockerin complexes revealed that cell surface dockerins contain two cohesin-binding interfaces, which can present different or identical specificities. In contrast to the current static model, we propose that dockerins utilize multivalent modes of cohesin recognition to recruit cellulosomes to the cell surface, a mechanism that maximises substrate access while facilitating complex assembly.
Lenis-rojas, {OA }, Fernandes {AR }, Roma-Rodrigues C, Baptista {PV }, Marques F, Pérez-Fernández D, Guerra-Varela J, Sánchez-Magraner L, Vázquez-garcía D, Torres L}{M, Fernández-Planells A, Fernández-Rosas J.
2016.
Heteroleptic mononuclear compounds of ruthenium(II): Synthesis, structural analyses, in vitro antitumor activity and in vivo toxicity on zebrafish embryos, dec. Dalton Transactions. 45:19127–19140., Number 47: RSC - Royal Society of Chemistry
AbstractThe limitations of platinum complexes in cancer treatment have motivated the extensive investigation into other metal complexes such as ruthenium. We herein present the synthesis and characterization of a new family of ruthenium compounds 1a–5a with the general formula [Ru(bipy)2L][CF3SO3]2 (bipy = 2,2′-bipyridine; L = bidentate ligand: N,N; N,P; P,P; P,As) which have been characterized by elemental analysis, ES-MS, 1H and 31P–{1H} NMR, FTIR and conductivity measurements. The molecular structures of four Ru(II) complexes were determined by single crystal X-ray diffraction. All compounds displayed moderate cytotoxic activity in vitro against human A2780 ovarian, MCF7 breast and HCT116 colorectal tumor cells. Compound 5a was the most cytotoxic compound against A2780 and MCF7 tumor cells with an IC50 of 4.75 ± 2.82 μM and 20.02 ± 1.46 μM, respectively. The compounds showed no cytotoxic effect on normal human primary fibroblasts but rather considerable selectivity for A2780, MCF7 and HCT116 tumor cells. All compounds induce apoptosis and autophagy in A2780 ovarian carcinoma cells and some nuclear DNA fragmentation. All compounds interact with CT-DNA with intrinsic binding constants in the order 1a > 4a > 2a > 3a > 5a. The observed hyperchromic effect may be due to the electrostatic interaction between positively charged cations and the negatively charged phosphate backbone at the periphery of the double helix-CT-DNA. Interestingly, compound 1a shows a concentration dependent DNA double strand cleavage. In addition in vivo toxicity has been evaluated on zebrafish embryos unveiling the differential toxicity between the compounds, with LC50 ranging from 8.67 mg L−1 for compound 1a to 170.30 mg L−1 for compound 2a.
Bernardo, M, Rodrigues S, Lapa N, Matos I, Lemos F, Batista MKS, Carvalho AP, Fonseca I.
2016.
High efficacy on diclofenac removal by activated carbon produced from potato peel waste, Aug. International Journal of Environmental Science and Technology. 13:1989–2000., Number 8
AbstractIn the present study, a novel porous carbon obtained by K2CO3 activation of potato peel waste under optimized conditions was applied for the first time as liquid-phase adsorbent of sodium diclofenac in parallel with a commercial activated carbon. The biomass-activated carbon presented an apparent surface area of 866 m2 g−1 and well-developed microporous structure with a large amount of ultramicropores. The obtained carbon presented leaching and ecotoxicological properties compatible with its safe application to aqueous medium. Kinetic data of laboratory-made and commercial sample were best fitted by the pseudo-second-order model. The commercial carbon presented higher uptake of diclofenac, but the biomass carbon presented the higher adsorption rate which was associated with its higher hydrophilic nature which favoured external mass transfer. Both adsorbents presented adsorption isotherms that were best fitted by Langmuir model. The biomass carbon and the commercial carbon presented adsorption monolayer capacities of 69 and 146 mg g−1, and Langmuir constants of 0.38 and 1.02 L mg−1, respectively. The better performance of the commercial sample was related to its slightly higher micropore volume, but the most remarkable effect was the competition of water molecules in the biomass carbon.
Roma-Rodrigues, C, Alves-Barroco C, Raposo {LR }, Costa {MN }, Fortunato E, Baptista {PMRV}, de Fernandes {MANCR}, Santos-Sanches I.
2016.
Infection of human keratinocytes by Streptococcus dysgalactiae subspecies dysgalactiae isolated from milk of the bovine udder, apr. Microbes And Infection. 18:290–293., Number 4: Elsevier Science B.V., Inc
AbstractStreptococcus dysgalactiae subsp. dysgalactiae (SDSD) are considered exclusive animal pathogens; however, a putative zoonotic upper limb cellulitis, a prosthetic joint infection and an infective endocarditis were described in humans. To unravel if bovine SDSD isolates are able to infect human cells, the adherence and internalization to human primary keratinocytes of two bovine SDSD strains isolated from milk collected from udder were analyzed. Bacterial adhesion assays and confocal microscopy indicate a high adherence and internalization of SDSD isolates to human cells, suggesting for the first time the ability of bovine isolates to infect human cells. (C) 2015 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.
Palma, SICJ, Fernandes AR, Roque ACA.
2016.
An affinity triggered MRI nanoprobe for pH-dependent cell labeling, 2016. RSC Advances. 6(114):113503-113512.: The Royal Society of Chemistry
AbstractThe pH-sensitive affinity pair composed by neutravidin and iminobiotin was used to develop a multilayered Magnetic Resonance Imaging (MRI) nanoprobe responsive to the acidic pH of tumor microenvironment. The multilayer system was assembled on meso-2,3-dimercaptosuccinic acid-coated iron oxide magnetic nanoparticles (MNP), which convey negative MRI contrast enhancement properties to the nanoprobe. The outer stealth PEG-layer is altered in acidic media due to the disruption of interactions between neutravidin-iminobiotin. As a consequence, the positively charged inner layer is exposed and enhances interactions with cells. The nanoprobe uptake by HCT116 cells cultured in vitro under acidic conditions had a 2-fold increase compared to the uptake at physiological pH. The uptake difference is particularly clear in T2-weighted MRI phantoms of cells incubated with the nanoprobes at both pH conditions. This work sets the proof-of-concept of a MNP-based MRI nanoprobe targeting acidic tumor microenvironment through the use of a specific bio-recognition interaction that is pH-sensitive. This tumor targeting strategy is potentially applicable to the generality of tumors since the typical hypoxic conditions and high glycolysis rate in cancer cells create an acidic environment common to the majority of cancer types.
Lenis-Rojas, OA, Fernandes AR, Roma-Rodrigues C, Baptista PV, Marques F, Perez-Fernandez D, Guerra-Varela J, Sanchez L, Vazquez-Garcia D, Torres LM, Fernandez A, Fernandez JJ.
2016.
Heteroleptic mononuclear compounds of ruthenium(ii): synthesis, structural analyses, in vitro antitumor activity and in vivo toxicity on zebrafish embryos, 2016. Dalton Transactions. 45(47):19127-19140.: The Royal Society of Chemistry
AbstractThe limitations of platinum complexes in cancer treatment have motivated the extensive investigation into other metal complexes such as ruthenium. We herein present the synthesis and characterization of a new family of ruthenium compounds 1a-5a with the general formula [Ru(bipy)2L][CF3SO3]2 (bipy = 2,2[prime or minute]-bipyridine; L = bidentate ligand: N,N; N,P; P,P; P,As) which have been characterized by elemental analysis, ES-MS, 1H and 31P-{1H} NMR, FTIR and conductivity measurements. The molecular structures of four Ru(ii) complexes were determined by single crystal X-ray diffraction. All compounds displayed moderate cytotoxic activity in vitro against human A2780 ovarian, MCF7 breast and HCT116 colorectal tumor cells. Compound 5a was the most cytotoxic compound against A2780 and MCF7 tumor cells with an IC50 of 4.75 +/- 2.82 [small mu ]M and 20.02 +/- 1.46 [small mu ]M, respectively. The compounds showed no cytotoxic effect on normal human primary fibroblasts but rather considerable selectivity for A2780, MCF7 and HCT116 tumor cells. All compounds induce apoptosis and autophagy in A2780 ovarian carcinoma cells and some nuclear DNA fragmentation. All compounds interact with CT-DNA with intrinsic binding constants in the order 1a > 4a > 2a > 3a > 5a. The observed hyperchromic effect may be due to the electrostatic interaction between positively charged cations and the negatively charged phosphate backbone at the periphery of the double helix-CT-DNA. Interestingly, compound 1a shows a concentration dependent DNA double strand cleavage. In addition in vivo toxicity has been evaluated on zebrafish embryos unveiling the differential toxicity between the compounds, with LC50 ranging from 8.67 mg L-1 for compound 1a to 170.30 mg L-1 for compound 2a.
Bari, M, Loureiro J, Pudas M, Tappura K, Jaakola K, Ruoho M, Tittonen I, Volz S, Pavan C, Costabello K, Bollen D, Haslam M, Ferreira I.
2016.
TransFlexTeg: Large area transparent thin film thermoelectric devices for smart window and flexible applications, 20-23 Sep. 14th European Conference on Thermoelectrics, ECT 2016.
AbstractThe main objective of TransFlexTeg is to develop an innovative large area distributed sensor network integrating transparent thin film thermoelectric devices and sensors for multifunctional smart windows and flexible high impact volume applications. Different breakthrough concepts will be developed: 1) large area high performance transparent thermoelectric thin films deposited on flexible substrates for thermal energy harvesting; 2) low cost high throughput thin film thermal sensors for thermal mapping and gesture sensing; 3) flexible smart windows and walls with energy harvesting, environmental sensing and wireless communication functionalities. This technology aims to demonstrate the functionalities of a smart window able to measure air quality and environmental parameters such as temperature, sun radiation and humidity. The data is automatically collected and can be utilized for controlling heating, cooling and ventilation systems of indoors. Active radio interface enables long range communication and long term data collection with WiFi or a similar base station. The proposed concept of smart windows replaces several conventional sensors with a distributed sensor network that is integrated invisibly into windows. In addition to the power generated from the thermal energy harvesting, the thermoelectric elements (TE) are also used as temperature sensors that, while being distributed over large area, enable thermal mapping of the area instead of just one or a few values measured from particular points. This smart window can be produced on glass. The active layer itself can be flexible glass layer or polymer sheet, which will significantly broaden the field of applications and improve business opportunities. Both can be manufactured in batch, or in Roll to Roll Atomic Layer Deposition (R2R ALD) process. High environmental impact is expected with savings of more than 25% of the electrical usage of residential homes and office buildings.
Raposo, LR, Roma-Rodrigues C, Faísca P, Alves M, Henriques J, Carvalheiro MC, Corvo LM, Baptista PV, Pombeiro AJL, Fernandes AR.
2016.
Immortalization and characterization of a new canine mammary tumor cell line FR37-CMT. J. Veterinary and Comparative Oncology.
AbstractHere we describe the establishment of a new canine mammary tumour (CMT) cell line, FR37-CMT that does not show dependence on female hormonal signaling to induce tumour xenografts in NOD-SCID mice. FR37-CMT cell line has a stellate or fusiform shape, displays the ability to reorganize the collagen matrix, expresses vimentin, CD44 and shows the loss of E-cadherin which is considered a fundamental event in epithelial to mesenchymal transition (EMT). The up-regulation of ZEB1, the detection of phosphorylated ERK1/2 and the downregulation of DICER1 and miR-200c are also in accordance with the mesenchymal characteristics of FR37-CMT cell line. FR37-CMT shows a higher resistance to cisplatin (IC50>50 µM) and to doxorubicin (IC50>5.3 µM) compared with other CMT cell lines. These results support the use of FR37-CMT as a new CMT model that may assist the understanding of the molecular mechanisms underlying EMT, CMT drug resistance, fostering the development of novel therapies targeting CMT.
Martins, M, Baptista PV, Mendo AS, Correia C, Videira P, Rodrigues AS, Muthukumaran J, Santos-Silva T, Silva A, da Silva FGMC, Gigante J, Duarte A, Pombeiro AJL, Fernandes AR.
2016.
In vitro and in vivo biological characterization of the anti-proliferative potential of a cyclic trinuclear organotin(IV) complex. Molecular BioSystems. (12)
AbstractIdentification of novel molecules that can selectively inhibit the growth of tumor cells, avoid causing side effects to patients and/or intrinsic or acquired resistance, usually associated with common chemotherapeutic agents, is of utmost importance. Organometallic compounds have gained importance in oncologic chemotherapy, such as organotin(IV) complexes. In this study, we assessed the anti-tumor activity of the cyclic trinuclear organotin(IV) complex with an aromatic oximehydroxamic acid group [nBu2Sn(L)]3(H2L = N,2-dihydroxy-5-[N-hydroxyethanimidoyl]benzamide) – MG85 – and provided further characterization of its biological targets. We have previously shown the high anti-proliferative activity of this complex against human colorectal and hepatocellular carcinoma cell lines and lower cytotoxicity in neonatal non-tumor fibroblasts. MG85 induces tumor cell apoptosis and down-regulation of proteins related to tubulin dynamics (TCTP and COF1). Further characterization included the: (i) evaluation of interference in the cell cycle progression, including the expression of critical genes; (ii) affinity to DNA and the corresponding mode of binding; (iii) genotoxic potential in cells with deficient DNA repair pathways; and (iv) in vivo tumor reduction efficiency using mouse colorectal carcinoma xenografts.
Cordeiro, T, Santos AFM, Nunes G, Cunha G, Sotomayor JC, Fonseca IM, F. Danède, Dias CJ, Cardoso MM, N. T. Correia, Viciosa MT, Dionísio M.
2016.
Accessing the Physical State and Molecular Mobility of Naproxen Confined to Nanoporous Silica Matrixes. The Journal of Physical Chemistry C . 120(26):14390–14401.
Palma, SICJ, Fernandes AR, Roque ACA.
2016.
An affinity triggered MRI nanoprobe for pH-dependent cell labeling. RSC Adv.. 6:113503–113512., Number 114: Royal Society of Chemistry
AbstractThe pH-sensitive affinity pair composed by neutravidin and iminobiotin was used to develop a multilayered Magnetic Resonance Imaging (MRI) nanoprobe responsive to the acidic pH of tumor microenvironment. The multilayer system was assembled on meso-2,3-dimercaptosuccinic acid-coated iron oxide magnetic nanoparticles (MNP), which convey negative MRI contrast enhancement properties to the nanoprobe. The outer stealth PEG-layer is altered in acidic media due to the disruption of interactions between neutravidin–iminobiotin. As a consequence, the positively charged inner layer is exposed and enhances interactions with cells. The nanoprobe uptake by HCT116 cells cultured in vitro under acidic conditions had a 2-fold increase compared to the uptake at physiological pH. The uptake difference is particularly clear in T2-weighted MRI phantoms of cells incubated with the nanoprobes at both pH conditions. This work sets the proof-of-concept of a MNP-based MRI nanoprobe targeting acidic tumor microenvironment through the use of a specific bio-recognition interaction that is pH-sensitive. This tumor targeting strategy is potentially applicable to the generality of tumors since the typical hypoxic conditions and high glycolysis rate in cancer cells create an acidic environment common to the majority of cancer types.
Fernandes, CSM, dos Santos R, Ottengy S, Viecinski AC, Béhar G, Mouratou B, Pecorari F, Roque ACA.
2016.
Affitins for protein purification by affinity magnetic fishing. Journal of Chromatography A. 1457:50–58.: Elsevier B.V.
AbstractCurrently most economical and technological bottlenecks in protein production are placed in the down-stream processes. With the aim of increasing the efficiency and reducing the associated costs, variousaffinity ligands have been developed. Affitins are small, yet robust and easy to produce, proteins derivedfrom the archaeal extremophilic “7 kDa DNA-binding” protein family. By means of combinatorial pro-tein engineering and ribosome display selection techniques, Affitins have shown to bind a diversity oftargets. In this work, two previously developed Affitins (anti-lysozyme and anti-IgG) were immobilizedonto magnetic particles to assess their potential for protein purification by magnetic fishing. The opti-mal lysozyme and human IgG binding conditions yielded 58 mg lysozyme/g support and 165 mg IgG/gsupport, respectively. The recovery of proteins was possible in high yield (≥95{%}) and with high purity,namely ≥95{%} and 81{%}, when recovering lysozyme from Escherichia coli supernatant and IgG from humanplasma, respectively. Static binding studies indicated affinity constants of 5.0 × 104M−1and 9.3 × 105M−1for the anti-lysozyme and anti-IgG magnetic supports. This work demonstrated that Affitins, which canbe virtually evolved for any protein of interest, can be coupled onto magnetic particles creating novelaffinity adsorbents for purification by magnetic fishing.
Fortunato, Gaspar, Diana, Duarte, Candido, Pereira, Águas, Hugo, Vicente, António, Dourado, Fernando, Gama, F. M., Martins R.
2016.
Chapter 11 - Optoelectronic Devices from Bacterial NanoCellulose. Bacterial Nanocellulose. :19pp..: Elsevier Inc.
Soares, PIP, Sousa AI, Silva JC, Ferreira I, Novo C, Borges JP.
2016.
Chitosan-based nanoparticles as drug delivery systems for doxorubicin: optimization and modelling. Carbohydrate polymers. 147:304-312.
AbstractIn the present work, two drug delivery systems were produced by encapsulating doxorubicin into chitosan and O-HTCC (ammonium-quaternary derivative of chitosan) nanoparticles. The results show that doxorubicin release is independent of the molecular weight and is higher at acidic pH (4.5) than at physiological pH. NPs with an average hydrodynamic diameter bellow 200 nm are able to encapsulate up to 70% and 50% of doxorubicin in the case of chitosan and O-HTCC nanoparticles, respectively. O-HTCC nanoparticles led to a higher amount of doxorubicin released than chitosan nanoparticles, for the same experimental conditions, although the release mechanism was not altered. A burst effect occurs within the first hours of release, reaching a plateau after 24 h. Fitting mathematical models to the experimental data led to a concordant release mechanism between most samples, indicating an anomalous or mixed release, which is in agreement with the swelling behavior of chitosan described in the literature.
Soares, PIP, Sousa AI, Silva JC, Ferreira IMM, Novo CMM, Borges JP.
2016.
Chitosan-based nanoparticles as drug delivery systems for doxorubicin: Optimization and modelling. Carbohydr Polym. 147:304-312.
AbstractIn the present work, two drug delivery systems were produced by encapsulating doxorubicin into chitosan and O-HTCC (ammonium-quaternary derivative of chitosan) nanoparticles. The results show that doxorubicin release is independent of the molecular weight and is higher at acidic pH (4.5) than at physiological pH. NPs with an average hydrodynamic diameter bellow 200 nm are able to encapsulate up to 70% and 50% of doxorubicin in the case of chitosan and O-HTCC nanoparticles, respectively. O-HTCC nanoparticles led to a higher amount of doxorubicin released than chitosan nanoparticles, for the same experimental conditions, although the release mechanism was not altered. A burst effect occurs within the first hours of release, reaching a plateau after 24 h. Fitting mathematical models to the experimental data led to a concordant release mechanism between most samples, indicating an anomalous or mixed release, which is in agreement with the swelling behavior of chitosan described in the literature.
Vinhas, R, Correia C, Ribeiro P, Lourenço A, de Sousa AB, Fernandes AR, Baptista PV.
2016.
Colorimetric assessment of BCR-ABL1 transcripts in clinical samples via gold nanoprobes. Analytical and Bioanalytical Chemistry. 408(19):5277–5284.
AbstractGold nanoparticles functionalized with thiolated oligonucleotides (Au-nanoprobes) have been used in a range of applications for the detection of bioanalytes of interest, from ions to proteins and DNA targets. These detection strategies are based on the unique optical properties of gold nanoparticles, in particular, the intense color that is subject to modulation by modification of the medium dieletric. Au-nanoprobes have been applied for the detection and characterization of specific DNA sequences of interest, namely pathogens and disease biomarkers. Nevertheless, despite its relevance, only a few reports exist on the detection of RNA targets. Among these strategies, the colorimetric detection of DNA has been proven to work for several different targets in controlled samples but demonstration in real clinical bioanalysis has been elusive. Here, we used a colorimetric method based on Au-nanoprobes for the direct detection of the e14a2 BCR-ABL fusion transcript in myeloid leukemia patient samples without the need for retro-transcription. Au-nanoprobes directly assessed total RNA from 38 clinical samples, and results were validated against reverse transcription-nested polymerase chain reaction (RT-nested PCR) and reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The colorimetric Au-nanoprobe assay is a simple yet reliable strategy to scrutinize myeloid leukemia patients at diagnosis and evaluate progression, with obvious advantages in terms of time and cost, particularly in low- to medium-income countries where molecular screening is not routinely feasible.