By Type: Journal Article

Size-Dependent Biological Activities of Fluorescent Organosilane-Modified Zinc Oxide Nanoparticles, s}il{\u a}, Mariana Bu{\c, a}b{\u a}caru Aurel T. {\u, s}sat Viorica Mu{\c, Vasile {Bogdan S}tefan} {\c, Nea{\c s}u {Ionela Andreea}, Pinheiro Teresa, Roma-Rodrigues Catarina, Baptista {Pedro V. }, Fernandes {Alexandra R. }, Matos {António Pedro}, and Marques {Fernanda Marujo} , Journal of biomedical nanotechnology, feb, Volume 16, Number 2, p.137–152, (2020) Abstract

Surface modification of zinc oxide nanoparticles (ZnO NPs) is a strategy to tune their biocompatibility. Herein we report on the synthesis of a series of fluorescent ZnO NPs modified with 2-10% (3-glycidyloxypropyl)trimethoxysilane (GPTMS) to investigate the fluorescence properties and to explore their applications in microbiology and biomedicine. The obtained ZnO NPs were characterized by X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM) and Fourier transform infrared spectroscopy (FTIR). Size reduction occurred from ca. 13 nm in unmodified ZnO to 3-4 nm in silane-modified samples and fluorescence spectra showed size-dependent variation of the photoemission bands' intensity. The antibacterial and cytotoxic activities were investigated on Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria, and in ovarian (A2780) and prostate (PC3) cancer cells by tetrazolium/formazan-based methods. The antibacterial effect was higher for E. coli than S. aureus, while the cytotoxic activity was similar for both cancer cells and varied with the particle size. Cell death by apoptosis, and/or necrosis versus autophagy, were explored by flow cytometry using an Annexin V based-method and transmission electron microscopy (TEM). The main mechanism of ZnO NPs toxicity may involve the generation of reactive oxygen species (ROS) and the induction of apoptosis or autophagy. This work revealed the potential utility of GPTMS-modified ZnO NPs in the treatment of bacterial infection and cancer.

Light Irradiation of Gold Nanoparticles Toward Advanced Cancer Therapeutics, Amendoeira, Ana, García {Lorenzo Rivas}, Fernandes {Alexandra R. }, and Baptista {Pedro V. } , Advanced Therapeutics, jan, Volume 3, Number 1, (2020) Abstract

Cancer is one of the leading causes of death in the world. To challenge this epidemic, there are growing demands for the development of new advanced and targeted therapeutics capable of effectively tackling cancer cells with improved selectivity. Nanomedicine has put forward several innovative therapeutics toward improving therapeutic efficacy while decreasing the deleterious side effects of current chemotherapy. Multifunctional gold nanoparticles (AuNPs) have been at the core of a plethora of advanced therapeutic strategies that provide selective targeting with their unique optical properties, capable to interact with the light of specific wavelength to deliver therapy with tremendous spatiotemporal precision. AuNPs have been exploited as photodynamic and photothermal therapeutic agents alone or in combination with other cancer treatment modalities with other cancer applications. Due to their exceptional physicochemical properties, they have been proven efficacious allies for photodynamic therapy and for photothermal therapy regimens. Herein, the rapidly progressing literature related to the use of these promising strategies against cancer is discussed, highlighting their possible future clinical translation.

Structural characterization and biological properties of silver(I) tris(pyrazolyl)methane sulfonate, Almeida, J., Roma-Rodrigues Catarina, Mahmoud {Abdallah G. }, {Guedes da Silva} Fátima {M. C. }, Pombeiro {Armando J. L. }, Martins {Luísa M. D. R. S. }, Baptista {Pedro V. }, and Fernandes {Alexandra R. } , Journal of Inorganic Biochemistry, oct, Volume 199, (2019) 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.

Nanotheranostics Targeting the Tumor Microenvironment, Roma-Rodrigues, Catarina, Pombo Inês, Raposo Luís, Pedrosa Pedro, Fernandes {Alexandra R. }, and Baptista {Pedro V. } , Frontiers in Bioengineering and Biotechnology, aug, Volume 7, p.197, (2019) 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.

Antibody modified gold nanoparticles for fast colorimetric screening of rheumatoid arthritis, Veigas, Bruno, Matias Ana, Calmeiro Tomás, Fortunato Elvira, Fernandes {Alexandra R. }, and Baptista {Pedro Viana} , Analyst, jun, Volume 144, Number 11, p.3613–3619, (2019) 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.

Occurrence of non-toxic bioemulsifiers during polyhydroxyalkanoate production by Pseudomonas strains valorizing crude glycerol by-product, Kourmentza, Constantina, Araújo Diana, Sevrin Chantal, Roma-Rodriques Catarina, Ferreira {Joana Lia}, Freitas Filomena, Dionisio Madalena, Baptista {Pedro V. }, Fernandes {Alexandra R. }, Grandfils Christian, and Reis {Maria A. M. } , Bioresource Technology, jun, Volume 281, p.31–40, (2019) 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.

Ionic Liquids and Salts from Ibuprofen as Promising Innovative Formulations of an Old Drug, Santos, {Miguel M. }, Raposo {Luís R. }, c}alo Carrera {Gon{\c V. S. M. }, Costa Alexandra, Dionísio Madalena, Baptista {Pedro V. }, Fernandes {Alexandra R. }, and Branco {Luís C. } , Chemmedchem, may, Volume 14, Number 9, (2019) 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.

Structural aspects of a trimetallic Cu II derivative: cytotoxicity and anti-proliferative activity on human cancer cell lines, Das, Kuheli, Datta Amitabha, Massera Chiara, Roma-Rodrigues Catarina, Barroso Mariana, Baptista {Pedro V. }, and Fernandes {Alexandra R. } , Journal of Coordination Chemistry, apr, Volume 72, Number 5-7, p.920–940, (2019) 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.

Enhancement of water solubility of poorly water-soluble drugs by new biocompatible N-acetyl amino acid N-alkyl cholinium-based ionic liquids, Jesus, {Ana R. }, Soromenho {Mário R. C. }, Raposo {Luís R. }, Esperan{\c c}a {José M. S. S. }, Baptista {Pedro V. }, Fernandes {Alexandra R. }, and Reis {Patrícia M. } , European Journal of Pharmaceutics and Biopharmaceutics, apr, Volume 137, p.227–232, (2019) 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.

New lessons from ancient life: marine invertebrates as a source of new drugs, Rodrigo, {A. P. }, Martins C., Tanoeiro L., Casaca M., Lopes {A. R. }, Parola {A. J. }, Matos {A. P. }, Baptista {P. V. }, Fernandes {A. R. }, and Costa {P. M. } , Annals of Medicine, mar, Volume 51, Number Suppl.1, p.S45–S46, (2019) Abstract
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Targeting Tumor Microenvironment for Cancer Therapy, Roma-Rodrigues, Catarina, Mendes Rita, Baptista {Pedro V. }, and Fernandes {Alexandra R. } , International Journal of Molecular Sciences, feb, Volume 20, Number 4, (2019) 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.

Counteracting the effect of leukemia exosomes by antiangiogenic gold nanoparticles, Roma-Rodrigues, Catarina, Fernandes {Alexandra R. }, and Baptista {Pedro V. } , International journal of nanomedicine, Volume 14, p.6843–6854, (2019) 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.

Liquid biopsies in myeloid malignancies, Abdulmawjood, {Bilal R. }, Roma-Rodrigues Catarina, Fernandes {Alexandra R. }, and Baptista {Pedro V. } , Cancer Drug Resistance, Volume 2, Number 4, p.1044–1061, (2019) Abstract

Hematologic malignancies are the most common type of cancer affecting children and young adults, and encompass diseases, such as leukemia, lymphoma, and myeloma, all of which impact blood associated tissues such as the bone marrow, lymphatic system, and blood cells. Clinical diagnostics of these malignancies relies heavily on the use of bone marrow samples, which is painful, debilitating, and not free from risks for leukemia patients. Liquid biopsies are based on minimally invasive assessment of markers in the blood (and other fluids) and have the potential to improve the efficacy of diagnostic/therapeutic strategies in leukemia patients, providing a useful tool for the real time molecular profiling of patients. The most promising noninvasive biomarkers are circulating tumor cells, circulating tumor DNA, microRNAs, and exosomes. Herein, we discuss the role of assessing these circulating biomarkers for the understanding of tumor progression and metastasis, tumor progression dynamics through treatment and for follow-up.

Paper-Based SERS Platform for One-Step Screening of Tetracycline in Milk, Marques, Ana, Veigas Bruno, Araújo Andreia, Pagará Beatriz, Baptista {Pedro Viana}, Águas Hugo, Martins Rodrigo, and Fortunato Elvira , Scientific Reports, dec, Volume 9, Number 1, (2019) 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.

GLUT1 and GLUT3 involvement in anthocyanin gastric transport- Nanobased targeted approach, Oliveira, Hélder, Roma-Rodrigues Catarina, Santos Ana, Veigas Bruno, Brás Natércia, Faria Ana, c}ão Calhau Concei{\c, {de Freitas} Victor, Baptista {Pedro V. }, Mateus Nuno, Fernandes {Alexandra R. }, and Fernandes Iva , Scientific Reports, dec, Volume 9, Number 1, (2019) 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.

Antiproliferative activity of heterometallic sodium and potassium-dioxidovanadium(V) polymers, Sutradhar, Manas, Alegria {Elisabete C. B. A. }, Ferretti Francesco, Raposo {Luís R. }, {Guedes da Silva} Fátima {M. C. }, Baptista {Pedro V. }, Fernandes {Alexandra R. }, and Pombeiro {Armando J. L. } , Journal of Inorganic Biochemistry, nov, Volume 200, (2019) 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.

Targeting cancer resistance via multifunctional gold nanoparticles, Pedrosa, Pedro, Corvo Luísa} {M., Ferreira-Silva Margarida, Martins Pedro, Carvalheiro {Manuela Colla}, Costa {Pedro M. }, Martins Carla, Martins {L. M. D. R. S., Baptista {Pedro V. }, and Fernandes {Alexandra R. } , International Journal of Molecular Sciences, nov, Volume 20, Number 21, (2019) 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.

Gold nanoprobe-based non-crosslinking hybridization for molecular diagnostics: an update, Baptista, {Pedro V. } , Expert Review Of Molecular Diagnostics, sep, Volume 18, Number 9, p.767–773, (2018) Abstract

Introduction: An update on the uses and applications of the non-cross-linking (NCL) hybridization assay based on the spectral modulation of gold nanoparticles (AuNPs) are presented, emphasizing DNA and RNA detection. Areas covered: Nanotechnology is strongly impacting the way we address diagnostics and therapeutics. In fact, nanoscale devices and particles have been used in a variety of platforms for improved biosensing and, more interestingly, for molecular diagnostics. AuNPs have been used in a great diversity of DNA and RNA detection strategies that are based on their nanoscale properties. Their unique optical properties have put them at the forefront of colorimetric sensing platforms. Among these, those relying on the NCL mechanism using DNA-modified AuNPs have shown remarkable versatility and simplicity for molecular detection of human pathogens, identification of single base alterations at the basis of human disease, gene expression, among others. Application of the NCL assay to molecular diagnostics will be discussed considering the challenges for validation and clinically relevant targets. Expert commentary: Integration of the NCL approach using AuNPs into chip biosensing platforms, projecting miniaturization and portability, will be addressed in terms of the future, i.e. clinical validation and translation to market.

Nano-strategies to fight multidrug resistant bacteria-{"}A Battle of the Titans{"}, Baptista, {Pedro V. }, McCusker {Matthew P. }, Carvalho Andreia, Ferreira {Daniela A. }, Mohan {Niamh M. }, Martins M., and Fernandes {Alexandra R. } , Frontiers in Microbiology, jul, Volume 9, Number JUL, (2018) Abstract

Infectious diseases remain one of the leading causes of morbidity and mortality worldwide. The WHO and CDC have expressed serious concern regarding the continued increase in the development of multidrug resistance among bacteria. Therefore, the antibiotic resistance crisis is one of the most pressing issues in global public health. Associated with the rise in antibiotic resistance is the lack of new antimicrobials. This has triggered initiatives worldwide to develop novel and more effective antimicrobial compounds as well as to develop novel delivery and targeting strategies. Bacteria have developed many ways by which they become resistant to antimicrobials. Among those are enzyme inactivation, decreased cell permeability, target protection, target overproduction, altered target site/enzyme, increased efflux due to over-expression of efflux pumps, among others. Other more complex phenotypes, such as biofilm formation and quorum sensing do not appear as a result of the exposure of bacteria to antibiotics although, it is known that biofilm formation can be induced by antibiotics. These phenotypes are related to tolerance to antibiotics in bacteria. Different strategies, such as the use of nanostructured materials, are being developed to overcome these and other types of resistance. Nanostructured materials can be used to convey antimicrobials, to assist in the delivery of novel drugs or ultimately, possess antimicrobial activity by themselves. Additionally, nanoparticles (e.g., metallic, organic, carbon nanotubes, etc.) may circumvent drug resistance mechanisms in bacteria and, associated with their antimicrobial potential, inhibit biofilm formation or other important processes. Other strategies, including the combined use of plant-based antimicrobials and nanoparticles to overcome toxicity issues, are also being investigated. Coupling nanoparticles and natural-based antimicrobials (or other repurposed compounds) to inhibit the activity of bacterial efflux pumps; formation of biofilms; interference of quorum sensing; and possibly plasmid curing, are just some of the strategies to combat multidrug resistant bacteria. However, the use of nanoparticles still presents a challenge to therapy and much more research is needed in order to overcome this. In this review, we will summarize the current research on nanoparticles and other nanomaterials and how these are or can be applied in the future to fight multidrug resistant bacteria.

Optical and Structural Characterization of a Chronic Myeloid Leukemia DNA Biosensor, Cordeiro, Mílton, Otrelo-Cardoso {Ana Rita Castro}, Svergun {Dmitri I. }, Konarev {Petr V. }, Lima {João Carlos}, Santos-Silva Teresa, and Baptista {Pedro Viana} , ACS Chemical Biology, may, Volume 13, Number 5, p.1235–1242, (2018) Abstract

Selective base pairing is the foundation of DNA recognition. Here, we elucidate the molecular and structural details of a FRET-based two-component molecular beacon relying on steady-state fluorescence spectroscopy, small-angle X-ray scattering (SAXS), microscale thermophoresis (MST), and differential electrophoretic mobility. This molecular beacon was designed to detect the most common fusion sequences causing chronic myeloid leukemia, e14a2 and e13a2. The emission spectra indicate that the self-assembly of the different components of the biosensor occurs sequentially, triggered by the fully complementary target. We further assessed the structural alterations leading to the specific fluorescence FRET signature by SAXS, MST, and the differential electrophoretic mobility, where the size range observed is consistent with hybridization and formation of a 1:1:1 complex for the probe in the presence of the complementary target and revelator. These results highlight the importance of different techniques to explore conformational DNA changes in solution and its potential to design and characterize molecular biosensors for genetic disease diagnosis.

Nanoparticle-AntagoMIR based targeting of MIR-31 to induce osterix and osteocalcin expression in mesenchymal stem cells, McCully, Mark, Conde João, Baptista {Pedro V. }, Mullin Margaret, Dalby {Matthew J. }, and Berry {Catherine C. } , PLoS ONE, feb, Volume 13, Number 2, (2018) Abstract

Mesenchymal stem cells are multipotent adult stem cells capable of generating bone, cartilage and fat, and are thus currently being exploited for regenerative medicine. When considering osteogenesis, developments have been made with regards to chemical induction (e.g. differentiation media) and physical induction (e.g. material stiffness, nanotopography), targeting established early transcription factors or regulators such as runx2 or bone morphogenic proteins and promoting increased numbers of cells committing to osteo-specific differentiation. Recent research highlighted the involvement of microRNAs in lineage commitment and terminal differentiation. Herein, gold nanoparticles that confer stability to short single stranded RNAs were used to deliver MiR-31 antagomiRs to both pre-osteoblastic cells and primary human MSCs in vitro. Results showed that blocking miR-31 led to an increase in osterix protein in both cell types at day 7, with an increase in osteocalcin at day 21, suggesting MSC osteogenesis. In addition, it was noted that antagomiR sequence direction was important, with the 5 prime reading direction proving more effective than the 3 prime. This study highlights the potential that miRNA antagomiR-Tagged nanoparticles offer as novel therapeutics in regenerative medicine.

Evaluation of cell toxicity and DNA and protein binding of green synthesized silver nanoparticles, Ribeiro, {A. P. C. }, Anbu S., Alegria {E. C. B. A. }, Fernandes {A. R. }, Baptista {P. V. }, Mendes R., Matias {A. S. }, Mendes M., {Guedes da Silva} {M. F. C. }, and Pombeiro {A. J. L. } , Biomedicine and Pharmacotherapy, may, Volume 101, p.137–144, (2018) Abstract

Silver nanoparticles (AgNPs) were prepared by GREEN chemistry relying on the reduction of AgNO3 by phytochemicals present in black tea extract. AgNPs were fully characterized by transmission electron microscopy (TEM), ultraviolet-visible spectroscopy ((UV-vis)), X-ray diffraction (XRD) and energy dispersive absorption spectroscopy (EDS). The synthesized AgNPs induced a decrease of the cell viability in a dose-dependent manner with a low IC50 (0.5 ± 0.1 μM) for an ovarian carcinoma cell line (A2780) compared to primary human fibroblasts (IC50 5.0 ± 0.1 μM). The DNA binding capability of CT (calf thymus) DNA was investigated using electronic absorption and fluorescence spectroscopies, circular dichroism and viscosity titration methods. Additionally, the AgNPs strongly quench the intrinsic fluorescence of BSA, as determined by synchronous fluorescence spectra.

Synthesis, Cytotoxicity Evaluation in Human Cell Lines and in Vitro DNA Interaction of a Hetero-Arylidene-9(10H)-Anthrone, Peixoto, Daniela, Figueiredo Margarida, Malta Gabriela, Roma-Rodrigues Catarina, Baptista {Pedro V. }, Fernandes {Alexandra R. }, Barroso Sónia, Carvalho {Ana Luísa}, Afonso {Carlos A. M. }, Ferreira {Luisa M. }, and Branco {Paula S. } , European Journal of Organic Chemistry, jan, Volume 2018, Number 4, p.545–549, (2018) Abstract

A new and never before reported hetero-arylidene-9(10H)-anthrone structure (4) was unexpectedly isolated on reaction of 1,2-dimethyl-3-ethylimidazolium iodide (2) and 9-anthracenecarboxaldehyde (3) under basic conditions. Its structure was unequivocally confirmed by X-ray crystallography. No cytotoxicity in human healthy fibroblasts and in two different cancer cell lines was observed, indicating its applicability in biological systems. Compound 4 interacts with CT-DNA by intercalation between the adjacent base pairs of DNA with a high binding affinity [Kb = 2.0 (±0.20) × 105 m–1], which is 10 × higher than that described for doxorubicin [Kb = 3.2 (±0.23) × 104 m–1]. Furthermore, compound 4 quenches the fluorescence emission of a GelRed–CT-DNA system with a quenching constant (KSV) of 3.3 (±0.3) × 103 m–1 calculated by the Stern–Volmer equation.

A novel BCR-ABL1 mutation in a patient with philadelphia chromosome-positive B-cell acute lymphoblastic leukemia, Vinhas, Raquel, Louren{\c c}o Alexandra, Santos Susana, Lemos Marcos, Ribeiro Patrícia, {de Sousa} {Aida Botelho}, Baptista {Pedro Viana}, and Fernandes {Alexandra Ramos} , OncoTargets and Therapy, jan, Volume 11, p.8589–8598, (2018) Abstract

Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) represents the most common genetic subtype of adult ALL (20%–30%) and accounts for approximately 50% of all cases in the elderly. It has been considered the subgroup of ALL with the worst outcome. The introduction of tyrosine kinase inhibitors (TKIs) allows complete hematologic remission virtually in all patients, with improved disease-free survival and overall survival. Nevertheless, the emergence of resistant mutations in BCR-ABL1 may require different TKI strategies to overcome the patient’s resistance and disease relapse. Here, we report a Ph+ B-ALL case with persistent minimal residual disease (MRD) after treatment with dasatinib. The patient expressed the P190BCR-ABL1 isoform and a novel BCR-ABL1 mutation, p.Y440C. The latter is in the C-terminal lobe of the kinase domain, which likely induces deviations in the protein structure and activity and destabilizes its inactive conformation. The treatment was substituted by bosutinib, which binds to the active conformation of the protein, prior to allogeneic bone marrow transplant to overcome the lack of a complete response to dasatinib. These findings strengthen the importance of BCR-ABL1 mutational screening in Ph+ patients, particularly for those who do not achieve complete molecular remission.

Combination of chemotherapy and Au-nanoparticle photothermy in the visible light to tackle doxorubicin resistance in cancer cells, Pedrosa, Pedro, Mendes Rita, Cabral Rita, Martins {Luísa M. D. R. S. }, Baptista {Pedro V. }, and Fernandes {Alexandra R. } , Scientific Reports, dec, Volume 8, Number 1, (2018) 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.

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