Browsing by Author "Valdiglesias, Vanessa"
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- Adequacy of the standardised in vitro mammalian cell Micronucleus (MN) test for nanomaterials genotoxicity testingPublication . Fernández-Bertólez, Natalia; Rodríguez-Fernández, R.; Lema-Arranz, C.; Pásaro, E.; Brandão, Fátima; Teixeira, João Paulo; Costa, Carla; Valdiglesias, Vanessa; Laffon, BlancaAbout adequacy of the standardised in vitro mammalian cell Micronucleus (MN) test for nanomaterials genotoxicity testing.
- Applicability of EU(7)-PIM criteria in cross-national studies in European countriesPublication . Fialová, Daniela; Brkić, Jovana; Laffon, Blanca; Reissigová, Jindra; Grešáková, Silvia; Dogan, Soner; Doro, Peter; Tasić, Ljiljana; Marinković, Valentina; Valdiglesias, Vanessa; Costa, Solange; Kostřiba, JanBackground: The European Union (EU)(7)-PIM (potentially inappropriate medication) list presents the most comprehensive and up-to-date tool for evaluation of PIM prescribing in Europe; however, several country-specific studies have documented lower specificity of this list on pharmaceutical markets of some countries. The aim of our study was to describe approval rates and marketing of PIMs stated by EU(7)-PIM criteria in six EU countries [in comparison with the American Geriatric Society (AGS) Beers 2015 criteria]. Methods: Research teams of six EU countries (Czech Republic, Spain, Portugal, Serbia, Hungary and Turkey) participated in this study conducted by WG1b EU COST Action IS1402 group in the period October 2015-November 2018. Data on approval rates of PIMs and their availability on pharmaceutical markets have been obtained from databases of national drug-regulatory institutes and up-to-date drug compendia. The EU(7)-PIM list and AGS Beers 2015 Criteria (Section 1) were applied. Results: PIMs from EU(7)-PIM list were approved for clinical use more often than those from the AGS Beers 2015 criteria (Section 1). Approval rates for EU(7)-PIMs ranged from 42.8% in Serbia to 71.4% in Spain (for AGS criteria only from 36.4% to 65.1%, respectively). Higher percentages of approved PIMs were documented in Spain (71.4%), Portugal (67.1%) and Turkey (67.5%), lower in Hungary (55.5%), Czech Republic (50.2%) and Serbia (42.8%). The majority of approved PIMs were also currently marketed in all countries except in Turkey (19.8-21.7% not marketed PIMs) and less than 20% of PIMs were available as over-the-counter medications (except in Turkey, 46.4-48.1%). Conclusions: The EU(7)-PIM list was created for utilization in European studies; however, applicability of this list is still limited in some countries, particularly in Eastern and Central Europe. The EU project EUROAGEISM H2020 (2017-2021) that focuses on PIM prescribing and regulatory measures in Central and Eastern European countries must consider these limits.
- Are iron oxide nanoparticles safe? Current knowledge and future perspectivesPublication . Valdiglesias, Vanessa; Fernández-Bertólez, Natalia; Kiliç, Gözde; Costa, Carla; Costa, Solange; Fraga, Sonia; Bessa, Maria Joao; Pásaro, Eduardo; Teixeira, João Paulo; Laffon, BlancaDue to their unique physicochemical properties, including superparamagnetism, iron oxide nanoparticles (ION) have a number of interesting applications, especially in the biomedical field, that make them one of the most fascinating nanomaterials. They are used as contrast agents for magnetic resonance imaging, in targeted drug delivery, and for induced hyperthermia cancer treatments. Together with these valuable uses, concerns regarding the onset of unexpected adverse health effects following exposure have been also raised. Nevertheless, despite the numerous ION purposes being explored, currently available information on their potential toxicity is still scarce and controversial data have been reported. Although ION have traditionally been considered as biocompatible - mainly on the basis of viability tests results - influence of nanoparticle surface coating, size, or dose, and of other experimental factors such as treatment time or cell type, has been demonstrated to be important for ION in vitro toxicity manifestation. In vivo studies have shown distribution of ION to different tissues and organs, including brain after passing the blood-brain barrier; nevertheless results from acute toxicity, genotoxicity, immunotoxicity, neurotoxicity and reproductive toxicity investigations in different animal models do not provide a clear overview on ION safety yet, and epidemiological studies are almost inexistent. Much work has still to be done to fully understand how these nanomaterials interact with cellular systems and what, if any, potential adverse health consequences can derive from ION exposure.
- Assessing the in vitro toxicity of airborne (nano)particles to the human respiratory system: from basic to advanced modelsPublication . Bessa, Maria João; Brandão, Fátima; Rosário, Fernanda; Moreira, Luciana; Reis, Ana Teresa; Valdiglesias, Vanessa; Laffon, Blanca; Fraga, Sónia; Teixeira, João PauloSeveral studies have been conducted to address the potential adverse health risks attributed to exposure to nanoscale materials. While in vivo studies are fundamental for identifying the relation-ship between dose and occurrence of adverse effects, in vitro model systems provide important information regarding the mechanism(s) of action at the molecular level. With a special focus on exposure to inhaled (nano)particulate material toxicity assessment, this review provides an over-view of the available human respiratory models and exposure systems for in vitro testing, advan-tages, limitations, and existing investigations using models of different complexity. A brief overview of the human respiratory system, pathway and fate of inhaled (nano)particles is also presented.
- Assessment of oxidative damage induced by iron oxide nanoparticles on different nervous system cellsPublication . Fernández-Bertólez, Natalia; Costa, Carla; Bessa, Maria João; Park, Magriet; Carriere, Marie; Dussert, Fanny; Teixeira, João Paulo; Pásaro, Eduardo; Laffon, Blanca; Valdiglesias, VanessaIron oxide nanoparticles (ION) have received much attention for their utility in biomedical applications, such as magnetic resonance imaging, drug delivery and hyperthermia, but concerns regarding their potential harmful effects are also growing. Even though ION may induce different toxic effects in a wide variety of cell types and animal systems, there is a notable lack of toxicological data on the human nervous system, particularly important given the increasing number of applications on this specific system. An important mechanism of nanotoxicity is reactive oxygen species (ROS) generation and oxidative stress. On this basis, the main objective of this work was to assess the oxidative potential of silica-coated (S-ION) and oleic acid-coated (O-ION) ION on human SH-SY5Y neuronal and A172 glial cells. To this aim, ability of ION to generate ROS (both in the absence and presence of cells) was determined, and consequences of oxidative potential were assessed (i) on DNA by means of the 8-oxo-7,8-dihydroguanine DNA glycosylase (OGG1)-modified comet assay, and (ii) on antioxidant reserves by analyzing ratio of reduced glutathione (GSH) to oxidized glutathione (GSSG). Conditions tested included a range of concentrations, two exposure times (3 and 24 h), and absence and presence of serum in the cell culture media. Results confirmed that, even though ION were not able to produce ROS in acellular environments, ROS formation was increased in the neuronal and glial cells by ION exposure, and was parallel to induction of oxidative DNA damage and, only in the case of neuronal cells treated with S-ION, to decreases in the GSH/GSSG ratio. Present findings suggest the production of oxidative stress as a potential action mechanism leading to the previously reported cellular effects, and indicate that ION may pose a health risk to human nervous system cells by generating oxidative stress, and thus should be used with caution.
- Association of inflammatory mediators with frailty status in older adults: results from a systematic review and meta-analysisPublication . Marcos-Pérez, Diego; Sánchez-Flores, María; Proietti, Stefania; Bonassi, Stefano; Costa, Solange; Teixeira, Joao Paulo; Fernández-Tajes, Juan; Pásaro, Eduardo; Laffon, Blanca; Valdiglesias, VanessaFrailty is a geriatric syndrome defined as a status of extreme vulnerability to stressors, leading to a higher risk of negative health-related outcomes. "Inflammaging", an age-related state of low-grade chronic inflammation, is characterized by an increased concentration of pro-inflammatory cytokines and acute phase proteins. Inflammaging has been postulated as an underlying mechanism of frailty, and several studies tested the relationship between frailty and concentration of inflammatory mediators. The aim of this systematic review and meta-analysis was to test whether inflammatory mediators are overproduced in frail older adults. Among the 758 articles identified in the literature search, 50 were included in the systematic review, and 39 in the three meta-analyses, i.e., C-reactive protein (CRP), interleukin 6 (IL6), and tumor necrosis factor α. To reduce heterogeneity, meta-analyses were restricted to studies identifying frailty by the Fried et al. [1] [J. Gerontol. A. Biol. Sci. Med. Sci. 56, M146-56] phenotypic criteria. Quantitative analyses measuring the association between frailty and biomarker concentrations showed significant differences when frail subjects were compared to non-frail and pre-frail subjects for CRP and IL6. This work established strong association between inflammatory biomarkers and frailty, confirming the role of age-related chronic inflammation in frailty development.
- Avaliação in vitro da neurotoxicidade de nanopartículas de magnetite revestidas por sílicaPublication . Costa, Carla; Brandão, Fátima; Kiliç, Gözde; Fernández-Bertólez, Natalia; Bessa, M. João; Costa, Solange; Valdiglesias, Vanessa; Laffon, Blanca; Teixeira, João Paulo
- Biocompatibility evaluation of CeO2 nanoparticles to be employed as nanodrugs in brain cancer nanomedicinePublication . Fernández-Bertólez, Natália; Touzani, Assia; Martínez, L.; Reis, Ana Teresa; Fraga, Sónia; Teixeira, João Paulo; Costa, Carla; Pásaro, Eduardo; Laffon, Blanca; Valdiglesias, VanessaCerium dioxide nanoparticles (CeO2NP) have recently gained attention for their unique structure-dependent properties, antioxidant enzyme-like behaviour, ROS scavenging activity and great potential for biomedical applications. In addition to their antioxidant and anti-inflammatory activity, CeO2NP are also known to exhibit anticancer potential, providing an attractive opportunity for use in cancer therapy, as a pharmacological agent and/or in drug/gene delivery systems [1]. Therefore, the main objective of this STSM was to evaluate the cytotoxic and genotoxic effects on human glioblastoma A172 cells exposed for 3, 24 and 48h to CeO2NP (1- 100µg/ml), to verify their safety to be used as possible nanomedicines for brain cancer treatment, specifically glioblastoma [2]. In addition, cell-specific differences in nanoceria effect were evaluated by comparing the results obtained with those observed in human neuronal SH-SY5Y cells exposed under the same experimental conditions. After carrying out the physicochemical characterization and analysing the cellular uptake of the CeO2NP, potential alterations in cell viability (MTT assay) and induction of DNA double-strand breaks (γH2AX assay) caused by the exposure were determined. The possible NP interference with assay methodologies was previously addressed and eliminated when necessary. Results obtained showed that, although there was a significant dose- and time-dependent internalization of NP by both cell types, nanoceria induced scarce cytotoxicity or genotoxicity in both cell lines, being restricted to the highest doses and longer exposure time tested. In general, data obtained suggest a high biocompatibility of CeO2NP under the tested conditions, except for glioblastoma cells exposed for 48h from 25 to 100µg/ml. These results provide a better understanding of the CeO2NP interaction with nervous system cells and their possible adverse effects. However, further studies are necessary to delve into the differential behaviour of these NP depending on the nervous cell type tested.
- Biomonitoring of occupational exposure to a known carcinogen: formaldehydePublication . Costa, Solange; Costa, Carla; Madureira, Joana; Valdiglesias, Vanessa; Teixeira- Gomes, Armanda; Laffon, Blanca; Teixeira, João PauloThe aim of the present study was to evaluate the occupational exposure to FA (n = 85) relating the exposure with different biomarkers and individual susceptibility, a control group (n = 87) was also evaluated. Genotoxicity was assessed by means of cytogenetic alterations and DNA damage, by comet assay (%TDNA)
- Cellular and Molecular Toxicity of Iron Oxide NanoparticlesPublication . Laffon, Blanca; Fernández-Bertólez, Natalia; Costa, Carla; Brandão, Fátima; Teixeira, João Paulo; Pásaro, Eduardo; Valdiglesias, VanessaIron oxide nanoparticles (ION) have attracted much attention because of their particular physico-chemical properties, including superparamagnetism. These features make them suitable for many purposes and several interesting biomedical applications, such as to increase contrast in magnetic resonance imaging (MRI), as drug delivery systems and as hyperthermia agents. However, they have also shown to be easily accumulated in diverse tissues and induce toxicity at different levels. This chapter reviews the different cellular and molecular effects induced by ION reported from in vitro studies with human and non-human cell lines. Those effects are mainly dependent on ION type and concentration, time of exposure, presence and nature of coating, and cell type evaluated. They include decreases in viability, plasmatic membrane disruption, oxidative damage, mitochondrial alterations, cell cycle impairments, cytoskeleton disruption, cell death, and alterations in cell motility, and in cell integrity. Despite these negative effects, the numerous advantages of ION together with their promising applications in biomedicine, make it necessary to clearly define their toxicity in order to discard potential health risks and to reach optimal benefits of their use.