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1.
Cent Eur J Public Health ; 28(3): 202-207, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32997476

RESUMO

OBJECTIVE: Nanomaterials consist of particles smaller than 100 nm - nanoparticles (NPs). Their nano dimensions allow them to penetrate through various membranes and enter into the bloodstream and disseminate into different body organs. Massive expansion of nanotechnologies together with production of new nanoparticles which have not yet been in contact with living organisms may pose a potential health problem. It is therefore necessary to investigate the health impact of NPs after experimental exposure. Comparison of the effect of TiO2 and NPs Fe3O4 in Wistar rats at time intervals 1, 7, 14 and 28 days was performed by studying the cytotoxic effect in the isolated inflammatory cells from bronchoalveolar lavage (BAL). METHODS: Wistar rats were intravenously (i.v.) given a suspension of NPs TiO2 or Fe3O4 (coated by sodium oleate) via the tail vein. After time intervals of 1, 7, 14 and 28 days, we sacrificed the animals under anaesthesia, performed BAL and isolated the cells. The number of animals in the individual groups was 7-8. We examined the differential count of BAL cells (alveolar macrophages - AM, polymorphonuclear leukocytes - PMN, lymphocytes - Ly); viability and phagocytic activity of AM; the proportion of immature and polynuclear cells and enzymes - cathepsin D - CAT D, lactate dehydrogenase - LDH and acid phosphatase - ACP. RESULTS: We found that TiO2 NPs are relatively inert - without induction of inflammatory and cytotoxic response. Exposure to nanoparticles Fe3O4 induced - under the same experimental conditions - in comparison with the control and TiO2 a more extensive inflammatory and cytotoxic response, albeit only at 1, 7 and 14 days after injection. CONCLUSIONS: The results suggest that TiO2 and Fe3O4 nanoparticles used in our study were transferred from the bloodstream to the respiratory tract, but this effect was not observed at 28 days after i.v. injection, probably due to their removal from the respiratory tract.


Assuntos
Óxido Ferroso-Férrico/toxicidade , Nanopartículas Metálicas/toxicidade , Doenças Respiratórias/induzido quimicamente , Titânio/toxicidade , Administração Intravenosa , Animais , Óxido Ferroso-Férrico/administração & dosagem , Nanopartículas Metálicas/administração & dosagem , Ratos , Ratos Wistar , Titânio/administração & dosagem
2.
Ecotoxicol Environ Saf ; 202: 110911, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32800246

RESUMO

Applications of TiO2 nanoparticles (NPs) in food, personal care products and industries pose risks on human health, particularly on vulnerable populations including pregnant women and infants. Fetus, deficient in mature defense system, is more susceptible to NPs. Publications on the developmental toxicity of TiO2 NPs on the maternal-exposed progeny have emerged. This review presents the main exposure routes of TiO2 NPs during pregnancy, including skin penetration, ingestion and inhalation, followed by transport of TiO2 NPs to the placenta. Accumulation of TiO2 NPs in placenta may cause dysfunction in nutrient transfer. TiO2 NPs can be even transported to the fetus and generate toxicities, such as impairments of nervous and reproductive system, and failure in lung and cardiovascular development. The toxicities rely on the crystalline phase and concentrations, and the main mechanisms include the accumulation of excessive reactive oxygen species, DNA damage, and over-activation of signaling pathways such as MAPK which impairs neurotransmission. Finally, this review remarks on the significance for identifying TiO2 NPs dosage safe for both mother and fetus, and particular attention should be paid at TiO2 NPs concentrations safe for mother but toxic to fetus. Importantly, research on the epigenetic trans-generational inheritance of TiO2 NPs is urgently needed to provide insights for deciding the prospects of TiO2 NPs applications.


Assuntos
Nanopartículas Metálicas/toxicidade , Titânio/toxicidade , Animais , Feminino , Feto , Humanos , Nanopartículas/toxicidade , Organogênese , Placenta/metabolismo , Gravidez , Efeitos Tardios da Exposição Pré-Natal/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Testes de Toxicidade
3.
Ecotoxicol Environ Saf ; 203: 111032, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32745774

RESUMO

Titanium dioxide nanoparticles (Np-TiO2) have become the common component of sunscreen cosmetic products. Np-TiO2 can affect especially aquatic ecosystems health, including aquatic organisms such as fish. It is therefore necessary to acquire a better understanding of the effect of Np-TiO2 on aquatic organisms. This study evaluated the biological effects of Np-TiO2 on Danio rerio, such as survival rate and weight change and, in particular, the Ti content or retention in the intestine and liver, as well as the activities of catalase and superoxide dismutase enzymes. In addition, the structure of the intestine, kidney, and liver was investigated through histological analysis. Ninety zebrafish were used, randomly divided into three treatment-groups: a control group (fed with food without adding Np-TiO2) and two groups of fish fed with food containing Np-TiO2 exposed for 7 and 14 days. The amount of Ti in the liver and intestine was measured using atomic absorption spectrophotometry coupled to a graphite furnace (GFAAS). Morphological analysis and enzyme catalase and superoxide dismutase assays were likewise performed. Ti was detected in all fish even in control group; probably Ti must have been introduced during production by the fish food industry. Structural changes were detected in fish fed with Np-TiO2 as vacuolization and disruption of the apical cytoplasm of epithelial cells that covered the intestinal villi. Although kidney morphology appeared intact, the lumen of the proximal tubule was enlarged, and the cells of the distal tubule were vacuolated. No morphological changes in the liver were detected; however, superoxide dismutase activity decreased, suggesting that liver changes occurred at the molecular level. Thus, Np-TiO2 causes morphological changes in the intestine, kidney, and liver of zebrafish and biochemical changes in the liver exposed for 7 and 14 days. Although not highly lethal, Np-TiO2 in the food chain can interfere with the morphophysiology of aquatic organisms. Neither mortalities nor body weight losses were recorded among fish in all groups over the duration of the experiment.


Assuntos
Mucosa Intestinal/efeitos dos fármacos , Rim/efeitos dos fármacos , Fígado/efeitos dos fármacos , Nanopartículas/toxicidade , Titânio/toxicidade , Poluentes Químicos da Água/toxicidade , Peixe-Zebra , Animais , Bioacumulação , Catalase , Relação Dose-Resposta a Droga , Ecossistema , Cadeia Alimentar , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Rim/metabolismo , Rim/patologia , Fígado/metabolismo , Fígado/patologia , Nanopartículas/metabolismo , Distribuição Aleatória , Protetores Solares/química , Titânio/metabolismo , Poluentes Químicos da Água/metabolismo
4.
Nanotoxicology ; 14(7): 985-1007, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32619159

RESUMO

Recent studies reported adverse liver effects and intestinal tumor formation after oral exposure to titanium dioxide (TiO2). Other oral toxicological studies, however, observed no effects on liver and intestine, despite prolonged exposure and/or high doses. In the present assessment, we aimed to better understand whether TiO2 can induce such effects at conditions relevant for humans. Therefore, we focused not only on the clinical and histopathological observations, but also used Adverse Outcome Pathways (AOPs) to consider earlier steps (Key Events). In addition, aiming for a more accurate risk assessment, the available information on organ concentrations of Ti (resulting from exposure to TiO2) from oral animal studies was compared to recently reported concentrations found in human postmortem organs. The overview obtained with the AOP approach indicates that TiO2 can trigger a number of key events in liver and intestine: Reactive Oxygen Species (ROS) generation, induction of oxidative stress and inflammation. TiO2 seems to be able to exert these early effects in animal studies at Ti liver concentrations that are only a factor of 30 and 6 times higher than the median and highest liver concentration found in humans, respectively. This confirms earlier conclusions that adverse effects on the liver in humans as a result of (oral) TiO2 exposure cannot be excluded. Data for comparison with Ti levels in human intestinal tissue, spleen and kidney with effect concentrations were too limited to draw firm conclusions. The Ti levels, though, are similar or higher than those found in liver, suggesting these tissues may be relevant too.


Assuntos
Mucosa Intestinal/efeitos dos fármacos , Rim/efeitos dos fármacos , Fígado/efeitos dos fármacos , Nanopartículas/toxicidade , Baço/efeitos dos fármacos , Titânio/toxicidade , Administração Oral , Animais , Aditivos Alimentares/química , Aditivos Alimentares/metabolismo , Aditivos Alimentares/toxicidade , Humanos , Inflamação , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Rim/metabolismo , Rim/patologia , Fígado/metabolismo , Fígado/patologia , Nanopartículas/química , Nanopartículas/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Baço/metabolismo , Baço/patologia , Titânio/química , Titânio/metabolismo
5.
Mutat Res ; 854-855: 503198, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32660822

RESUMO

TiO2 particles are broadly used in daily products, including cosmetics for their UV-absorbing property, food for their white colouring property, water and air purification systems, self-cleaning surfaces and photoconversion electrical devices for their photocatalytic properties. The toxicity of TiO2 nano- and microparticles has been studied for decades, and part of this investigation has been dedicated to the identification of their potential impact on DNA, i.e., their genotoxicity. This review summarizes data retrieved from their genotoxicity testing during the past 6 years, encompassing both in vitro and in vivo studies, mostly performed on lung and intestinal models. It shows that TiO2 particles, both nano- and micro-sized, produce genotoxic damage to a variety of cell types, even at low, realistic doses.


Assuntos
Mutagênicos/toxicidade , Titânio/toxicidade , Animais , DNA/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Humanos , Testes de Mutagenicidade/métodos
6.
Aquat Toxicol ; 225: 105541, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32574931

RESUMO

There has been a significant increased concern of the impact of the toxicity of multiple contaminants in the marine environment. Thus, this study was aimed at determining whether the interaction between nano-TiO2 and Cr(VI) would modulate their toxic effects with the marine crustacean, Artemia salina. Nano-TiO2 agglomerated in artificial sea water (ASW) and readily formed micron-sized particles that settled down in the medium. The addition of Cr(VI) to nano-TiO2 aggravated their agglomeration through sorption of Cr(VI) onto nano-TiO2. This was reflected by a decrease in the residual concentration of Cr in the suspension. Acute toxicity tests performed using pristine nano-TiO2 (0.25, 0.5, 1, 2, and 4 mg/L) and Cr(VI) (0.125, 0.25, 0.5, and 1 mg/L) displayed a concentration dependent rise in the mortality of Artemia salina. To examine the effects of mixtures of nano-TiO2 and Cr(VI) on Artemia salina, two groups of experiments were designed. The former group studied the toxic effect of nano-TiO2 (0.5, 1, 2, and 4 mg/L) with a fixed concentration (0.125 mg/L) of Cr(VI). While the latter group studied the toxicity of Cr(VI) (0.25, 0.5, and 1 mg/L) with a fixed concentration (0.25 mg/L) of nano-TiO2. The toxic effects of nano-TiO2 was not significantly reduced at a fixed concentration of Cr(VI) but in contrast, a significant reduction in the Cr(VI) toxicity by fixed concentration of nano-TiO2 was observed. Toxicity data was well supported by an independent action model that proved the mode of action between nano-TiO2 and Cr(VI) to be antagonistic. Furthermore, ROS generation and measurement of antioxidant enzyme activities were also in line with toxicity results. From this study, the modification of Cr(VI) toxicity at fixed concentration of nano-TiO2 could have a huge impact on the reduction in Cr(VI) toxicity across trophic levels.


Assuntos
Artemia/efeitos dos fármacos , Cromo/toxicidade , Nanopartículas/toxicidade , Titânio/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Artemia/enzimologia , Relação Dose-Resposta a Droga , Interações Medicamentosas , Tamanho da Partícula , Água do Mar/química
7.
Ecotoxicol Environ Saf ; 200: 110776, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32474243

RESUMO

Over the past decades, titanium dioxide nanoparticles (n-TiO2) have been extensively used in several industrial applications and the manufacture of novel consumer products. Although strict regulations have been put in place to limit their release into the aquatic environment, these nanoparticles can still be found at elevated levels within the environment, which can result in toxic effects on exposed organisms and has possible implications in term of public health. Bivalve mollusks are a unique and ideal group of shellfish for the study and monitoring the aquatic pollution by n-TiO2 because of their filter-feeding behaviour and ability to accumulate toxicants in their tissues. In these animals, exposure to n-TiO2 leads to oxidative stress, immunotoxicity, neurotoxicity, and genotoxicity, as well as behavioral and physiological changes. This review summarizes the uptake, accumulation, and fate of n-TiO2 in aquatic environments and the possible interactions between n-TiO2 and other contaminants such as heavy metals and organic pollutants. Moreover, the toxicological impacts and mechanisms of action are discussed for a wide range of bivalve mollusks. This data underlines the pressing need for additional knowledge and future research plans for the development of control strategies to mitigate the release of n-TiO2 to the aquatic environment to prevent the toxicological impacts on bivalves and protect public health.


Assuntos
Bivalves/efeitos dos fármacos , Nanopartículas/toxicidade , Titânio/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Bioacumulação , Bivalves/genética , Bivalves/metabolismo , Dano ao DNA , Ecotoxicologia , Metais Pesados/metabolismo , Metais Pesados/toxicidade , Nanopartículas/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/genética , Frutos do Mar , Titânio/metabolismo , Poluentes Químicos da Água/metabolismo
8.
Aquat Toxicol ; 225: 105543, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32585540

RESUMO

Species sensitivity distributions (SSDs) are used in chemical safety assessments to derive predicted-no-effect-concentrations (PNECs) for substances with a sufficient amount of relevant and reliable ecotoxicity data available. For engineered nanomaterials (ENMs), ecotoxicity data are often compromised by poor reproducibility and the lack of nano-specific characterization needed describe an ENM under test exposure conditions. This may influence the outcome of SSD modelling and hence the regulatory decision-making. This study investigates how the outcome of SSD modelling is influenced by: 1) Selecting input data based on the nano-specific "nanoCRED" reliability criteria, 2) Direct SSD modelling avoiding extrapolation of data by including long-term/chronic NOECs only, and 3) Weighting data according to their nano-specific quality, the number of data available for each species, and the trophic level abundance in the ecosystem. Endpoints from freshwater ecotoxicity studies were collected for the representative nanomaterials NM-300 K (silver) and NM-105 (titanium dioxide), evaluated for regulatory reliability and scored according to the level of nano-specific characterization conducted. The compiled datasets are unique in exclusively dealing with representative ENMs showing minimal batch-to-batch variation. The majority of studies were evaluated as regulatory reliable, while the degree of nano-specific characterization varied greatly. The datasets for NM-300 K and NM-105 were used as input to the nano-weighted n-SSWD model, the probabilistic PSSD+, and the conventional SSD Generator by the US EPA. The conventional SSD generally yielded the most conservative, but least precise HC5 values, with 95 % confidence intervals up to 100-fold wider than the other models. The inclusion of regulatory reliable data only, had little effect on the HC5 generated by the conventional SSD and the PSSD+, whereas the n-SSWD estimated different HC5 values based on data segregated according to reliability, especially for NM-105. The n-SSWD weighting of data significantly affected the estimated HC5 values, however in different ways for the sub-datasets of NM-300 K and NM-105. For NM-300 K, the inclusion of NOECs only in the weighted n-SSWD yielded the most conservative HC5 of all datasets and models (a HC5 based on NOECs only could not be estimated for NM-105, due to limited number of data). Overall, the estimated HC5 values of all models are within a relatively limited concentration range of 25-100 ng Ag/L for NM-300 K and 1-15 µgTiO2/L for NM-105.


Assuntos
Nanoestruturas/toxicidade , Testes de Toxicidade/métodos , Poluentes Químicos da Água/toxicidade , Ecossistema , Água Doce/química , Reprodutibilidade dos Testes , Medição de Risco , Prata/toxicidade , Titânio/toxicidade
9.
Int J Nanomedicine ; 15: 3447-3470, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32523343

RESUMO

Titanium dioxide (TiO2) nanostructures are one of the most plentiful compounds that have emerged in various fields of technology such as medicine, energy and biosensing. Various TiO2 nanostructures (nanotubes [NTs] and nanowires) have been employed in photoelectrochemical (PEC) biosensing applications, greatly enhancing the detection of targets. TiO2 nanostructures, used as reinforced material or coatings for the bare surface of titanium implants, are excellent additive materials to compensate titanium implants deficiencies-like poor surface interaction with surrounding tissues-by providing nanoporous surfaces and hierarchical structures. These nanostructures can also be loaded by diversified drugs-like osteoporosis drugs, anticancer and antibiotics-and used as local drug delivery systems. Furthermore, TiO2 nanostructures and their derivatives are new emerging antimicrobial agents to overcome human pathogenic microorganisms. However, like all other nanomaterials, toxicity and biocompatibility of TiO2 nanostructures must be considered. This review highlights recent advances, along with the properties and numerous applications of TiO2-based nanostructure compounds in nano biosensing, medical implants, drug delivery and antibacterial fields. Moreover, in the present study, some recent advances accomplished on the pharmaceutical applications of TiO2 nanostructures, as well as its toxicity and biocompatibility, are presented.


Assuntos
Tecnologia Biomédica/métodos , Nanoestruturas/química , Titânio/química , Anti-Infecciosos/farmacologia , Sistemas de Liberação de Medicamentos , Humanos , Próteses e Implantes , Titânio/toxicidade
10.
Ecotoxicol Environ Saf ; 201: 110816, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32521370

RESUMO

Mine tailings contain dangerously high levels of toxic metals which pose a constant threat to local ecosystems. Few naturally grown native plants can colonize tailings site and the existence of their root-associated microbial populations is poorly understood. The objective of this study was to give further insights into the interactions between native plants and their microbiota during natural attenuation of abandoned V-Ti magnetite mine tailings. In the present work, we first examined the native plants' potential for phytoremediation using plant/soil analytical methods and then investigated the root microbial communities and their inferred functions using 16 S rRNA-based metagenomics. It was found that in V-Ti magnetite mine tailings the two dominant plants Bothriochloa ischaemum and Typha angustifolia were able to increase available nitrogen in the rhizosphere soil by 23.3% and 53.7% respectively. The translocation factors (TF) for both plants indicated that B. ischaemum was able to accumulate Pb (TF = 1.212), while T. angustifolia was an accumulator of Mn (TF = 2.502). The microbial community structure was more complex in the soil associated with T. angustifolia than with B. ischaemum. The presence of both plants significantly reduced the population of Acinetobacter. Specifically, B. ischaemum enriched Massilia, Opitutus and Hydrogenophaga species while T. angustifolia significantly increased rhizobia species. Multivariate analyses revealed that among all tested soil variables Fe and total organic carbon (TOC) could be the key factors in shaping the microbial structure. The putative functional analysis indicated that soil sample of B. ischaemum was abundant with nitrate/nitrite reduction-related functions while that of T. angustifolia was rich in nitrogen fixing functions. The results indicate that these native plants host a diverse range of soil microbes, whose community structure can be shaped by plant types and soil variables. It is also possible that these plants can be used to improve soil nitrogen content and serve as bioaccumulators for Pb or Mn for phytoremediation purposes.


Assuntos
Óxido Ferroso-Férrico/toxicidade , Microbiota/efeitos dos fármacos , Raízes de Plantas/microbiologia , Poluentes do Solo/toxicidade , Titânio/toxicidade , Vanádio/toxicidade , Biodegradação Ambiental , China , Óxido Ferroso-Férrico/análise , Metagenômica , Microbiota/genética , Mineração , Poaceae/crescimento & desenvolvimento , Poaceae/microbiologia , Rhizobium , Rizosfera , Solo/química , Microbiologia do Solo , Poluentes do Solo/análise , Titânio/análise , Typhaceae/crescimento & desenvolvimento , Typhaceae/microbiologia , Vanádio/análise
11.
Chemosphere ; 252: 126563, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32443264

RESUMO

Climate change is leading to a gradual increase in the ocean temperature, which can cause physiological and biochemical impairments in aquatic organisms. Along with the environmental changes, the presence of emerging pollutants such as titanium dioxide (TiO2) in marine coastal systems has also been a topic of concern, especially considering the interactive effects that both factors may present to inhabiting organisms. In the present study, it has been assessed the effects of the presence in water of particles of rutile, the most common polymorph of TiO2, in Mytilus galloprovincialis, under actual and predicted warming conditions. Organisms were exposed to different concentrations of rutile (0, 5, 50, 100 µg/L) at control (18 ± 1.0 °C) and increased (22 ± 1.0 °C) temperatures. Histopathological and biochemical changes were evaluated in mussels after 28 days of exposure. Histopathological examination revealed similar alterations on mussels' gills and digestive glands with increasing rutile concentrations at both temperatures. Biochemical markers showed that contaminated mussels have an unchanged metabolic capacity at 18 °C, which increased at 22 °C. Although antioxidant defences were activated in contaminated organisms at 22 °C, cellular damage was still observed. Overall, our findings showed that histopathological impacts occurred after rutile exposure regardless of the temperature, while biochemical alterations were only significantly noticeable when temperature was enhanced to 22 °C. Thus, this study demonstrated that temperature rise may significantly enhance the sensitivity of bivalves towards emerging pollutants.


Assuntos
Mytilus/fisiologia , Titânio/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Antioxidantes/metabolismo , Biomarcadores/metabolismo , Mudança Climática , Brânquias/metabolismo , Mytilus/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Temperatura , Poluentes Químicos da Água/análise
12.
Chem Biol Interact ; 323: 109063, 2020 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-32224134

RESUMO

Exposure to TiO2 NPs induces several cellular alterations after NPs uptake including disruption of cytoskeleton that is crucial for lung physiology but is not considered as a footprint of cell damage. We aimed to investigate cytoskeleton disturbances and the impact on cell migration induced by an acute TiO2 NPs exposure (24 h) and the recovery capability after 6 days of NPs-free treatment, which allowed investigating if cytoskeleton damage was reversible. Exposure to TiO2 NPs (10 µg/cm2) for 24 h induced a decrease 20.2% and 25.1% in tubulin and actin polymerization. Exposure to TiO2 NPs (10 µg/cm2) for 24 h followed by 6 days of NPs-free had a decrease of 26.6% and 21.3% in tubulin and actin polymerization, respectively. The sustained exposure for 7 days to 1 µg/cm2 and 10 µg/cm2 induced a decrease of 22.4% and 30.7% of tubulin polymerization respectively, and 28.7% and 46.2% in actin polymerization. In addition, 24 h followed 6 days of NPs-free exposure of TiO2 NPs (1 µg/cm2 and 10 µg/cm2) decreased cell migration 40.7% and 59.2%, respectively. Cells exposed (10 µg/cm2) for 7 days had a decrease of 65.5% in cell migration. Ki67, protein surfactant B (SFTPB) and matrix metalloprotease 2 (MMP2) were analyzed as genes related to lung epithelial function. The results showed a 20% of Ki67 upregulation in cells exposed for 24 h to 10 µg/cm2 TiO2 NPs while a downregulation of 20% and 25.8% in cells exposed to 1 µg/cm2 and 10 µg/cm2 for 24 h followed by 6 days of NPs-free exposure. Exposure to 1 µg/cm2 and 10 µg/cm2 for 24 h and 7 days upregulates SFTPB expression in 53% and 59% respectively, MMP2 expression remain unchanged. In conclusion, exposure of TiO2 NPs affected cytoskeleton of lung epithelial cells irreversibly but this damage was not cumulative.


Assuntos
Citoesqueleto/patologia , Células Epiteliais/patologia , Pulmão/patologia , Nanopartículas/toxicidade , Titânio/toxicidade , Células A549 , Actinas/metabolismo , Movimento Celular/efeitos dos fármacos , Tamanho Celular , Sobrevivência Celular/efeitos dos fármacos , Citoesqueleto/efeitos dos fármacos , Endocitose , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/ultraestrutura , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Antígeno Ki-67/metabolismo , Metaloproteinase 2 da Matriz/metabolismo , Nanopartículas/ultraestrutura , Polimerização , Precursores de Proteínas/metabolismo , Proteínas Associadas a Surfactantes Pulmonares/metabolismo , Tubulina (Proteína)/metabolismo
13.
Environ Toxicol ; 35(8): 895-905, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32329576

RESUMO

Numerous studies have demonstrated the in vitro and in vivo neurotoxicity of nanoparticulate titanium dioxide (nano-TiO2 ), a mass-produced material for a large number of commercial and industrial applications. The mechanism of nano-TiO2 -induced inhibition of axonal development, however, is still unclear. In our study, primary cultured hippocampal neurons of 24-hour-old fetal Sprague-Dawley rats were exposed to 5, 15, or 30 µg/mL nano-TiO2 for 6, 12, and 24 hours, and the toxic effects of nano-TiO2 exposure on the axons development were detected and its molecular mechanism investigated. Nano-TiO2 accumulated in hippocampal neurons and inhibited the development of axons as nano-TiO2 concentrations increased. Increasing time in culture resulted in decreasing axon length by 32.5%, 36.6%, and 53.8% at 6 hours, by 49.4%, 53.8%, and 69.5% at 12 hours, and by 44.5%, 58.2%, and 63.6% at 24 hours, for 5, 15, and 30 µg/mL nano-TiO2 , respectively. Furthermore, nano-TiO2 downregulated expression of Netrin-1, growth-associated protein-43, and Neuropilin-1, and promoted an increase of semaphorin type 3A and Nogo-A. These studies suggest that nano-TiO2 inhibited axonal development in rat primary cultured hippocampal neurons and this phenomenon is related to changes in the expression of axon growth-related factors.


Assuntos
Nanopartículas/toxicidade , Neurônios/efeitos dos fármacos , Titânio/toxicidade , Animais , Axônios , Hipocampo/efeitos dos fármacos , Neurogênese , Neurônios/metabolismo , Proteínas Nogo/metabolismo , Ratos , Ratos Sprague-Dawley
14.
Environ Toxicol ; 35(9): 982-990, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32333507

RESUMO

In this work, we aimed to evaluate the adverse effects and the mechanism of intestinal barrier caused by titanium dioxide nanoparticles (TiO2 NPs). Here, the effects of two different dosages (300 and 1200 mg/kg) of TiO2 NPs on female mice (n = 5) were investigated. After 28-day oral exposure, the results of Ti content were significantly increased in the ileum in comparison with the control. The histopathological structure index of the ileum was significantly changed after TiO2 NPs exposure; villi height and crypt depth were decreased and increased, respectively. Meanwhile, TiO2 NPs treatment also significantly altered the transcription levels of genes. First, the GATA-3 and STAT-4 were upregulation and downregulation, respectively. Second, gene expressions of the Zonula Occludens-1, claudin (CLDN)-12, occludin, and myosin light chain kinase were significantly upregulated, while the CLDN-3 was decreased. Finally, the caspase-3, caspase-9, and caspase-12 were upregulated. The results of TUNEL staining indicated apoptosis in the ileum. In general, TiO2 NPs treatment significantly changed the intestine physical barrier in a dose-dependent manner. The toxicity of TiO2 NPs could be through the imbalance in the Th1/Th2.


Assuntos
Apoptose/efeitos dos fármacos , Íleo/efeitos dos fármacos , Nanopartículas/toxicidade , Equilíbrio Th1-Th2/efeitos dos fármacos , Titânio/toxicidade , Administração Oral , Animais , Relação Dose-Resposta a Droga , Feminino , Íleo/imunologia , Íleo/metabolismo , Íleo/patologia , Camundongos , Nanopartículas/ultraestrutura , Tamanho da Partícula , Propriedades de Superfície , Titânio/química , Titânio/farmacocinética
15.
Chemosphere ; 249: 126536, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32217413

RESUMO

This study investigated the influences of titanium dioxide nanoparticles (n-TiO2) on the thyroid endocrine disruption and neurobehavioral defects induced by pentachlorophenol (PCP) in zebrafish (Danio rerio). Embryos (2 h post-fertilization) were exposed to PCP (0, 3, 10, and 30 µg/L) or in combination with n-TiO2 (0.1 mg/L) until 6 days post-fertilization. The results showed that n-TiO2 alone did not affect thyroid hormones levels or transcriptions of related genes. Exposure to PCP significantly decreased thyroid hormone thyroxine (T4) content, thyroid stimulating hormone (TSH) level and transcription of thyroglobulin (tg), but significantly increased 3,5,3'-triiodothyronine (T3) level and upregulation of deiodinase 2 (dio2). In comparison, the co-exposure with n-TiO2 significantly reduced the content of T3 by depressing the potential targets, tg and dio2. For neurotoxicity, the single and co-exposure resulted in similar effects with significant downregulation of neurodevelopment-related genes (ELAV like RNA Binding Protein 3, elavl3; Growth associated protein-43, gap43; α-tubulin) and inhibited locomotor activity. The results indicated that the presence of n-TiO2 significantly enhanced the PCP-induced thyroid endocrine disruption but not the neurobehavioral defects in zebrafish larvae.


Assuntos
Disruptores Endócrinos/toxicidade , Pentaclorofenol/toxicidade , Peixe-Zebra/fisiologia , Animais , Sistema Endócrino/efeitos dos fármacos , Larva/efeitos dos fármacos , Nanopartículas/toxicidade , Pentaclorofenol/metabolismo , Glândula Tireoide/efeitos dos fármacos , Hormônios Tireóideos/metabolismo , Titânio/toxicidade , Tri-Iodotironina/metabolismo , Peixe-Zebra/metabolismo
16.
PLoS One ; 15(3): e0230299, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32191735

RESUMO

In this review, we highlight the current advancements in the field of triplet sensitization by three-dimensional (3D) perovskite nanocrystals and bulk films. First introduced in 2017, 3D perovskite sensitized upconversion (UC) is a young fast-evolving field due to the tunability of the underlying perovskite material. By tuning the perovskite bandgap, visible-to-ultraviolet, near-infrared-to-visible or green-to-blue UC has been realized, which depicts the broad applicability of this material. As this research field is still in its infancy, we hope to stimulate the field by highlighting the advantages of these perovskite nanocrystals and bulk films, as well as shedding light onto the current drawbacks. In particular, the keywords toxicity, reproducibility and stability must be addressed prior to commercialization of the technology. If successful, photon interconversion is a means to increase the achievable efficiency of photovoltaic cells beyond its current limits by increasing the window of useable wavelengths.


Assuntos
Compostos de Cálcio/química , Engenharia , Óxidos/química , Fótons , Titânio/química , Compostos de Cálcio/toxicidade , Óxidos/toxicidade , Reprodutibilidade dos Testes , Titânio/toxicidade , Testes de Toxicidade
17.
Mutat Res ; 849: 503142, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-32087856

RESUMO

E171 (titanium dioxide, TiO2), an authorized foods and beverage additive, is also used in food packaging and in pharmaceutical and cosmetic preparations. E171 is considered to be an inert and non-digestible material, not storable in animal tissues, but the possible presence of TiO2 nanoparticles (NP) may present a risk to human health and the environment. We determined the presence of 15% TiO2 NP in a commercial E171 food additive product, by electron microscopy. The biological effects of E171 were assessed in Lens culinaris and Allium cepa for the following endpoints: percentage of germination, root elongation, mitotic index, presence of chromosomal abnormalities, and micronuclei. The results indicated low phytotoxicity but dose-dependent genotoxicity. We also observed internalization of TiO2 NP and ultrastructural alterations in the root systems.


Assuntos
Aditivos Alimentares/toxicidade , Lens (Planta)/efeitos dos fármacos , Mutagênicos/toxicidade , Nanopartículas/toxicidade , Cebolas/efeitos dos fármacos , Titânio/toxicidade , Animais , Aberrações Cromossômicas/efeitos dos fármacos , Endocitose/efeitos dos fármacos , Germinação/efeitos dos fármacos , Humanos , Lens (Planta)/metabolismo , Lens (Planta)/ultraestrutura , Micronúcleos com Defeito Cromossômico , Microscopia Eletrônica , Índice Mitótico/estatística & dados numéricos , Cebolas/metabolismo , Cebolas/ultraestrutura , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Raízes de Plantas/ultraestrutura
18.
J Biotechnol ; 310: 54-61, 2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-32014560

RESUMO

The study was conducted to investigate the effects of foliar-intervention of nano-TiO2 on Cd toxicity in cowpea plants. Cowpea plants were exposed to Cd toxicity at 10 mg/kg soil for 21 days and afterwards, subjected to six episodes of foliar application of nano-TiO2 intervention. Results showed that foliar-applied nano-TiO2 significantly promoted chlorophyll b and total chlorophyll contents after Cd stress as compared to Cd-stressed plants without the intervention. Interestingly, Cd contents of roots, shoots and grains were significantly reduced (p < 0.05) after nano-TiO2 sprays compared to Cd-stressed plants. However, the Cd contents in edible tissues (leaves and seeds) after interventions remained above recommended threshold. Furthermore, nano-TiO2 interventions promoted stress enzymes activity in both roots and leaves as well as increased Zn, Mn and Co levels in seeds compared to Cd-stressed plants without intervention. Estimated daily intake of Cd in leaves and seeds for adult subpopulation exceeded the WHO recommended daily intake by some folds in Cd-stressed and nano-TiO2-treated plants. The health risk quotient (HQ) for adult subpopulation exceeded unitary in seeds from nano-TiO2 treatments (HQ = 1.75 and 1.96, respectively) while no potential risk was obtained for leaves. Overall, foliar application of nano-TiO2 portends significant ameliorative potential for Cd toxicity in cowpea plants.


Assuntos
Cádmio/toxicidade , Fibras na Dieta , Nanopartículas/efeitos adversos , Estresse Fisiológico/efeitos dos fármacos , Titânio/toxicidade , Vigna/metabolismo , Raízes de Plantas/metabolismo , Brotos de Planta/metabolismo , Sementes/metabolismo
19.
Nanotoxicology ; 14(4): 534-553, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32031460

RESUMO

Nanoscale titanium dioxide (TiO2) is manufactured in wide scale, with a range of applications in consumer products. Significant toxicity of TiO2 nanoparticles has, however, been recognized, suggesting considerable risk to human health. To evaluate fully their toxicity, assessment of the epigenetic action of these nanoparticles is critical. However, only few studies are available examining capability of nanoparticles to alter epigenetic integrity. In the present study, the effect of TiO2 nanoparticles exposure on DNA methylation, a major epigenetic mechanism, was investigated in in vitro cellular model systems. A panel of cells relevant to portals of human exposure (Caco-2 (colorectal), HepG2 (liver), NL20 (lung), and A-431 (skin)) was exposed to TiO2 nanoparticles to assess effects on global methylation, gene-specific methylation, and expression levels of DNA methyltransferases, MBD2, and UHRF1. Global methylation was determined by enzyme-linked immunosorbent assay-based immunochemical analysis. Degree of promoter methylation across a defined panel of genes was evaluated using EpiTect Methyl II Signature PCR System Array technology. Expression of DNMT1, DNMT3a, DNMT3b, MBD2, and URHF1 was quantified by qRT-PCR. Decrease in global DNA methylation in cell lines Caco-2, HepG2, and A-431 exposed to TiO2 nanoparticles was shown. Across four cell lines, eight genes (CDKN1A, DNAJC15, GADD45A, GDF15, INSIG1, SCARA3, TP53, and BNIP3) were identified in which promotors were methylated after exposure. Altered expression of these genes is associated with disease etiology. The results also revealed aberrant expression of epigenetic regulatory genes involved in DNA methylation (DNMT1, DNMT3a, DNMT3b, MBD2, and UHRF1) in TiO2 exposed cells, which was cell type dependent. Findings from this study clearly demonstrate the impact of TiO2 nanoparticles exposure on DNA methylation in multiple cell types, supporting potential involvement of this epigenetic mechanism in the toxicity of TiO2 nanoparticles. Hence for complete assessment of potential risk from nanoparticle exposure, epigenetic studies are critical.


Assuntos
Metilação de DNA/efeitos dos fármacos , Epigênese Genética/efeitos dos fármacos , Nanopartículas/toxicidade , Titânio/toxicidade , Proteínas Estimuladoras de Ligação a CCAAT/genética , Linhagem Celular Tumoral , DNA (Citosina-5-)-Metiltransferases/genética , Expressão Gênica/efeitos dos fármacos , Proteínas de Choque Térmico HSP40/genética , Humanos , Regiões Promotoras Genéticas , Ubiquitina-Proteína Ligases/genética
20.
Environ Monit Assess ; 192(2): 144, 2020 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-31989337

RESUMO

Assessing the environmental hazard of nanoparticles can be a challenging task using various testing strategies. However, to our knowledge, no information is available about the impact of the sample preparation on the toxicity and toxicity mechanism of nanoparticles. For this aim, three sample preparation methods and their available toxicity procedures were conducted to examine the (eco) toxicity of TiO2 nanoparticles using bacteria model system. To detail understanding of the effect of sample preparation, the key events on the inhibition were examined by physicochemical and antioxidant responses. The findings showed that the physicochemical and toxicological behavior of the tested TiO2 NPs varied according to the sample preparation method.


Assuntos
Nanopartículas , Titânio , Monitoramento Ambiental , Nanopartículas/toxicidade , Titânio/toxicidade
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