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1.
Ecotoxicol Environ Saf ; 138: 309-319, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28062079

RESUMO

Titanium dioxide nanoparticles (TiO2-NPs) have a wide number of applications in cosmetic, solar and paint industries due to their photocatalyst and ultraviolet blocking properties. The continuous increase in the production of TiO2-NPs enhances the risk for this manufactured nanomaterial to enter water bodies through treated effluents or agricultural amendments. TiO2-NPs have shown very low toxicity in a number of aquatic organisms. However, there are no conclusive data about their deleterious effects and on their possible mechanisms of toxic action. At this level, in vitro cell culture systems are a useful tool to gain insight about processes underlying the toxicity of a wide variety of substances, including nanomaterials. Differences in the physiology of different taxa make advisable the use of cells coming from the taxon of interest, but collecting data from a variety of cellular types allows a better understanding of the studied processes. Taking all this into account, the aim of the present study was to assess the toxicity of three types of TiO2-NP, rutile hydrophobic (NM-103), rutile hydrophilic (NM-104) and rutile-anatase (NM-105), obtained from the EU Joint Research Centre (JRC) repository, using various fish cell lines (RTG-2, PLHC-1, RTH-149, RTL-W1) and rainbow trout primary hepatocytes. For comparative purposes, the effect of different dispersion protocols, end-point assays and extended exposure time was studied in a fish cell line (RTG-2) and in the rat hepatoma cell line (H4IIE). TiO2-NPs dispersions showed a variable degree of aggregation in cell culture media. Disruption of mitochondrial metabolic activity, plasma membrane integrity and lysosome function was not detected in any cell line after exposure to TiO2-NPs at any time and concentration ranges tested. These results are indicative of a low toxicity of the TiO2-NPs tested and show the usefulness of fish cells maintained in vitro as high throughput screening methods that can facilitate further testing in the framework of integrated testing strategies.


Assuntos
Membrana Celular/efeitos dos fármacos , Lisossomos/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Mitocôndrias/efeitos dos fármacos , Titânio/toxicidade , Animais , Carcinoma Hepatocelular , Linhagem Celular Tumoral , Hepatócitos , Interações Hidrofóbicas e Hidrofílicas , Oncorhynchus mykiss , Ratos
2.
Chemosphere ; 364: 143005, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39121965

RESUMO

Graphene oxide (GO) is a very attractive material for use in a vast number of applications. However, before its widespread use, it is important to consider potential issues related to environmental safety to support its safe application. The aim of this study was to investigate effects on fish (rainbow trout) following GO exposure. Using both an in vitro approach with the RTL W1 rainbow trout liver cell line, and in vivo exposures, following OECD TG 203, disturbances at the cellular level as well as in the gills and liver tissue of juvenile trout were assessed. In RTL W1 cells, a time and concentration-dependent loss in cell viability, specifically plasma membrane integrity and lysosomal function, was observed after 96 h of exposure to GO at concentrations ≥18.75 mg/L. Additionally, increased reactive oxygen species (ROS) levels were evidenced at concentrations ≥18.75 mg/L, and an enhancement of metabolic activity was noted with concentrations ≥4.68 mg/L. In vivo exposures to GO did not provoke mortality in rainbow trout juveniles following 96 h exposure but led to histological alterations in gills and liver tissues, induction of enzymatic detoxification activities in the liver, as well as aryl hydrocarbon receptor (ahr)-cytochrome P450 1a (cyp1a) gene expression downregulation, and upregulation of pro-inflammatory cytokines il1b and il8 at GO concentrations ≥9.89 mg/L.


Assuntos
Citocromo P-450 CYP1A1 , Brânquias , Grafite , Fígado , Oncorhynchus mykiss , Estresse Oxidativo , Espécies Reativas de Oxigênio , Receptores de Hidrocarboneto Arílico , Poluentes Químicos da Água , Animais , Oncorhynchus mykiss/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Receptores de Hidrocarboneto Arílico/metabolismo , Receptores de Hidrocarboneto Arílico/genética , Grafite/toxicidade , Poluentes Químicos da Água/toxicidade , Brânquias/efeitos dos fármacos , Brânquias/metabolismo , Citocromo P-450 CYP1A1/metabolismo , Citocromo P-450 CYP1A1/genética , Espécies Reativas de Oxigênio/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Inflamação , Inativação Metabólica , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos
3.
Toxics ; 12(2)2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38393192

RESUMO

Graphene-based conductive inks offer attractive possibilities in many printing technology applications. Often, these inks contain a mixture of compounds, such as solvents and stabilizers. For the safe(r) and sustainable use of such materials in products, potentially hazardous components must be identified and considered in the design stage. In this study, the hazards of few-layer graphene (FLG)-based ink formulations were tested in fish using in vitro (RTL-W1 cell line) and in vivo aquatic ecotoxicity tests (OECD TG 203). Five ink formulations were produced using different processing steps, containing varying amounts of solvents and stabilizers, with the end products formulated either in aqueous solutions or in powder form. The FLG ink formulations with the highest contents of the stabilizer sodium deoxycholate showed greater in vitro cytotoxic effects, but they did not provoke mortality in juvenile rainbow trout. However, exposure led to increased activities of the cytochrome P450 1a (Cyp1a) and Cyp3a enzymes in the liver, which play an essential role in the detoxification of xenobiotics, suggesting that any effects will be enhanced by the presence of the stabilizers. These results highlight the importance of an SSbD approach together with the use of appropriate testing tools and strategies. By incorporating additional processing steps to remove identified cytotoxic residual solvents and stabilizers, the hazard profile of the FLG inks improved, demonstrating that, by following the principles of the European Commission's safe(r) and sustainable by design (SSbD) framework, one can contribute to the safe(r) and sustainable use of functional and advanced 2D materials in products.

4.
ACS Nano ; 18(8): 6038-6094, 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38350010

RESUMO

Two-dimensional (2D) materials have attracted tremendous interest ever since the isolation of atomically thin sheets of graphene in 2004 due to the specific and versatile properties of these materials. However, the increasing production and use of 2D materials necessitate a thorough evaluation of the potential impact on human health and the environment. Furthermore, harmonized test protocols are needed with which to assess the safety of 2D materials. The Graphene Flagship project (2013-2023), funded by the European Commission, addressed the identification of the possible hazard of graphene-based materials as well as emerging 2D materials including transition metal dichalcogenides, hexagonal boron nitride, and others. Additionally, so-called green chemistry approaches were explored to achieve the goal of a safe and sustainable production and use of this fascinating family of nanomaterials. The present review provides a compact survey of the findings and the lessons learned in the Graphene Flagship.

5.
Chemosphere ; 310: 136894, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36265710

RESUMO

The bioaccumulation potential of spherical and rod-shaped CuO nanomaterials (NMs) was assessed in rainbow trout (Oncorhynchus mykiss) exposed via water and diet following the OECD Test Guideline No. 305. Fish were exposed via diet to both NMs at concentrations of 70 and 500 mg Cu/kg for 15 days, followed by 44 days of depuration. For water-borne exposure, only the rod-shaped CuO NMs were tested at 0.08 and 0.8 mg Cu/L for 28 days, followed by 14 days of depuration. The concentration of Cu was determined in fish whole body to derive biomagnification and bioconcentration factors (BMF and BCF). Different tissues were sampled to investigate the total Cu biodistribution and target organs as well as the particle number-based bioaccumulation of CuO NMs. Estimated BMF and BCF values were below the thresholds of concern. However, shape and route influenced depuration. Following dietary exposure, there was a higher depuration of Cu from fish exposed to the rod-shaped compared to the spherical CuO NMs. A higher depuration was also observed for rod-shaped CuO NMs following the dietary exposure compared the aqueous one. Despite the much higher dietary exposure concentrations of rod-shape CuO NMs, similar Cu body burdens were reached via water. Cu was found in particulate form in different tissues. Although these NMs had a low bioaccumulation potential, differences in distribution and elimination patterns of Cu were observed depending on the exposure route and particle shape. Careful consideration of the most relevant exposure route is needed when designing a bioaccumulation experiment for testing NMs.


Assuntos
Nanoestruturas , Oncorhynchus mykiss , Poluentes Químicos da Água , Animais , Bioacumulação , Distribuição Tecidual , Poluentes Químicos da Água/análise , Cobre , Água
6.
Environ Toxicol Chem ; 41(6): 1390-1406, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35226375

RESUMO

An integrated testing strategy for ecotoxicity assessment (ITS-ECO) was developed to aid in the hazard and fate assessment of engineered nanomaterials (ENMs) deposited in marine environments using the bivalve Mytilus spp. as a test species. The ENMs copper(II) oxide (CuO) and titanium dioxide (TiO2 ), either in pristine form (core) or with functionalized coatings (polyethylene glycol [PEG], carboxyl [COOH], and ammonia [NH3 ]) were selected as case study materials based on their production levels and use. High-throughput in vitro testing in Tier 1 of the ITS-ECO revealed CuO ENMs to elicit cytotoxic effects on lysosomes of hemocytes of mussels, with the hazard potential CuO PEG > CuO COOH > CuO NH3 > CuO core, whereas TiO2 ENMs were not cytotoxic. Genotoxicity in hemocytes as well as gill cells of mussels following in vivo exposure (48 h) to CuO ENMs was also seen. Longer in vivo exposures in Tier 2 (48 h-21 days) revealed subacute and chronic oxidative effects for both CuO and TiO2 ENMs, in some cases leading to lipid peroxidation (core TiO2 ENMs). In Tier 3 bioaccumulation studies, distinct patterns of uptake for Cu (predominantly in gills) and Ti (predominantly in digestive glands) and between the different core and coated ENMs were found. Clear NM-specific and coating-dependent effects on hazard and fate were seen. Overall, using a tiered testing approach, the ITS-ECO was able to differentiate the hazard (acute, subacute, and chronic effects) posed by ENMs of different compositions and coatings and to provide information on fate for environmental risk assessment of these ENMs. Environ Toxicol Chem 2022;41:1390-1406. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.


Assuntos
Mytilus , Nanoestruturas , Animais , Cobre/toxicidade , Nanoestruturas/química , Nanoestruturas/toxicidade , Titânio
7.
MethodsX ; 8: 101413, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34430308

RESUMO

The first step of nanomaterial accumulation in the aquatic environment is the uptake of particulate material. For substances with very low water solubility, exposure via water may be of limited relevance in comparison to the dietary route. The OECD Test Guideline 305 for bioaccumulation testing in fish using dietary exposure recommends to add substances to fish food following methodologies normally used in aquaculture (e.g. with a corn or fish oil vehicle). The feasibility of using such an approach for the testing of manufactured nanomaterials (MNs), due to their unique physical characteristics and solubility, needs to be investigated. In this study an easy, cost-effective method to prepare metal oxide nanoparticle (NP) spiked feed to give the required dietary exposure concentration to fish is described. Metal oxide NP (CeO2,TiO2 and ZnO) dispersions were prepared in oil (sunflower or olive oil) and used to soak fish feed pellets. NP surface deposition and homogeneity of distribution were analysed and confirmed. Discrepancies between nominal and measured concentrations highlighted the need to measure the achieved concentration in MN-spiked feed. The present method provides stable concentrations for bioaccumulation testing of MNs in fish through the dietary route. A method for•Fish feed preparation using nanomaterial-oil suspensions.•Homogenous spiking of nanomaterials on feed.•Nanomaterials stably maintained on feed immersed in water until eaten by fish.

8.
Food Chem Toxicol ; 126: 178-191, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30797875

RESUMO

Organically modified clays can be used as nanofillers in polymer-clay nanocomposites to create bio-based packaging with improved strength and barrier properties. The impact of organic modification on the physico-chemical properties and toxicity of clays has yet to be fully investigated but is essential to ensure their safe use. Two organoclays, named N116_HDTA and N116_TMSA, were prepared using a commercially available sodium bentonite clay and the organic modifiers hexadecyl trimethyl ammonium bromide (HDTA) and octadecyl trimethyl ammonium chloride (TMSA). An in vitro hazard assessment was performed using HaCaT skin cells, C3A liver cells, and J774.1 macrophage-like cells. Organic modification with HDTA and TMSA increased the hazard potential of the organoclays in all cell models, as evidenced by the higher levels of cytotoxicity measured. N116_TMSA caused the greatest loss in viability with IC50 values of 3.2, 3.6 and 6.1 µg/cm2 calculated using J774.1, HaCaT and C3A cell lines, respectively. Cytotoxic effects were dictated by the amount of free or displaced organic modifier present in the exposure suspensions. The parent bentonite clay also caused distinct cytotoxic effects in J774.1 macrophage-like cells with associated TNF-α release. Such information on the hazard profile of organoclays, can feed into risk assessments for these materials.


Assuntos
Argila/química , Embalagem de Alimentos/instrumentação , Hepatócitos/efeitos dos fármacos , Queratinócitos/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Nanocompostos/toxicidade , Polímeros/toxicidade , Animais , Sobrevivência Celular/efeitos dos fármacos , Cetrimônio/química , Cetrimônio/toxicidade , Hepatócitos/citologia , Humanos , Queratinócitos/citologia , Macrófagos/citologia , Camundongos , Nanocompostos/química , Polímeros/química , Compostos de Amônio Quaternário/química , Compostos de Amônio Quaternário/toxicidade
9.
Sci Total Environ ; 551-552: 334-43, 2016 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-26878645

RESUMO

The increasing use of ZnO nanoparticles (ZnO NPs) in different fields has raised concerns about the possible environmental risks associated with these NPs entering aquatic systems. In this study, using a dietary exposure route, we have analysed the tissue distribution and depuration pattern of Zn as well as any associated redox balance disturbances in rainbow trout (Oncorhynchus mykiss) following exposure to ZnO NPs (20-30nm). Fish were fed a diet spiked with ZnO NPs prepared from a dispersion in sunflower oil at doses of 300 or 1000mg ZnO NPs/kg feed for 10days. This uptake phase was followed by a 28days depuration phase in which fish from all groups received untreated feed. While no overt signs of toxicity were observed and no important effects in fish growth (weight and length) or in the hepatosomatic index among groups were recorded, we observed high levels of Zn bioaccumulation in the gills and intestine of exposed fish following exposure to both dose levels. Zn levels were not eliminated during the depuration phase and we have evidenced oxidative stress responses in gills associated with such long term ZnO NPs bioaccumulation and lack of elimination. Furthermore, exposures to higher doses of ZnO NPs (1000mg/kg feed) resulted in Zn distribution to the liver of fish following 10days of exposure. Fish from this exposure group experienced biochemical disturbances associated with oxidative stress in the liver and ethoxy-resorufin-O-deethylase (EROD) activity which may point to the ability of ZnO NPs or its ions to interfere with cytochrome P450 metabolic processes.


Assuntos
Nanopartículas/toxicidade , Oncorhynchus mykiss/metabolismo , Poluentes Químicos da Água/toxicidade , Óxido de Zinco/toxicidade , Zinco/metabolismo , Animais , Citocromo P-450 CYP1A1/metabolismo , Glutationa/metabolismo , Nanopartículas/metabolismo , Estresse Oxidativo , Distribuição Tecidual , Poluentes Químicos da Água/metabolismo , Óxido de Zinco/metabolismo
10.
Environ Toxicol Chem ; 35(10): 2562-2570, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-26970269

RESUMO

Ecosystems are exposed to a wide variety of individual substances, including at the nano-scale; and the potential adverse effects of their interactions are an increasing concern. The purpose of the present study was to determine whether zinc oxide nanoparticles (ZnONPs) at a no-observed-effect concentration modulate the cytotoxicity of copper nanoparticles (CuNPs) in the fish hepatoma cell line PLHC-1 after 48 h of exposure and the contribution of the released ions to these effects. Cells were exposed to 50-nm CuNPs (0.39-25.0 µg/mL), alone or in combination with ZnONPs (25 nm or 100 nm), at 6.25 µg/mL. Cells were exposed to suspensions of NPs or to their supernatants, as well as to their combinations. The effects on cell viability were assessed through cytotoxicity assays. Changes in cell morphology and metal internalization were also evaluated. The cytotoxicity exerted by CuNPs was enhanced in the presence of nontoxic concentrations of ZnONPs. On the contrary, Zn ions protected the cell line from the CuNP toxicity, this effect being related to an increase in the intracellular levels of Zn. This increase of metal was not observed in cells exposed to both ZnONPs and CuNPs, even when they were visualized inside the cell. The results indicated that the internalization of ZnONPs, but not the Zn ions, was responsible for the enhanced toxicity of the CuNPs. Environ Toxicol Chem 2016;35:2562-2570. © 2016 SETAC.


Assuntos
Cobre/toxicidade , Peixes , Nanopartículas Metálicas/toxicidade , Poluentes Químicos da Água/toxicidade , Óxido de Zinco/toxicidade , Animais , Técnicas de Cultura de Células , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Cobre/química , Relação Dose-Resposta a Droga , Interações Medicamentosas , Peixes/metabolismo , Íons , Nanopartículas Metálicas/química , Microscopia Eletrônica de Transmissão , Tamanho da Partícula , Propriedades de Superfície , Poluentes Químicos da Água/química , Óxido de Zinco/química
11.
Chem Biol Interact ; 228: 57-68, 2015 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-25617484

RESUMO

The generation of reactive oxygen species (ROS) and consequent oxidative stress is regarded as a relevant mechanism for nanoparticle toxicity. In cells, the activation of the aryl hydrocarbon receptor (AhR) triggers a cascade of defence responses against oxidative stress. By increasing AhR dependent cellular anti-oxidant activity, we tested the extent to which the cytotoxic effect of copper nanoparticles (CuNPs) is governed by oxidative stress. H4IIE rat hepatoma cells were challenged with high ROS levels after exposure to CuNPs, while the AhR-induced cellular anti-oxidant defence was simultaneously activated by the AhR ligand beta-Naphthoflavone (ßNF). Activation of phase II detoxification enzymes (as glutathione-S-transferases, GSTs) and anti-oxidants (glutathione, GSH) led to a complete abrogation of CuNP-induced ROS production. However, a concurrent reduction in cytotoxicity was not detected, thereby indicating that CuNPs exert non-oxidative stress mediated cytotoxic effects. Transmission electron microscopy analysis pointed to a direct physical perturbation of cellular structures by CuNPs, thus contributing to their cytotoxicity. Our observations highlight that distinct mechanisms underlie the toxicity of ions and NPs and indicate that while ROS elicitation is CuNP-specific, the cytotoxic action of these particles may not be directly related to their pro-oxidative activity. These findings have important implications with respect to the oxidative stress paradigm used to explain NP toxicity.


Assuntos
Antioxidantes/farmacologia , Cobre/toxicidade , Hepatócitos/citologia , Hepatócitos/efeitos dos fármacos , Homeostase/efeitos dos fármacos , Nanopartículas Metálicas/química , Receptores de Hidrocarboneto Arílico/metabolismo , Animais , Antioxidantes/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Cobre/química , Cobre/farmacologia , Hepatócitos/metabolismo , Oxirredução/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Ratos , Espécies Reativas de Oxigênio/metabolismo , Células Tumorais Cultivadas
12.
Int J Environ Res Public Health ; 12(5): 5386-405, 2015 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-26006119

RESUMO

Among all classes of nanomaterials, silver nanoparticles (AgNPs) have potentially an important ecotoxicological impact, especially in freshwater environments. Fish are particularly susceptible to the toxic effects of silver ions and, with knowledge gaps regarding the contribution of dissolution and unique particle effects to AgNP toxicity, they represent a group of vulnerable organisms. Using cell lines (RTL-W1, RTH-149, RTG-2) and primary hepatocytes of rainbow trout (Oncorhynchus mykiss) as in vitro test systems, we assessed the cytotoxicity of the representative AgNP, NM-300K, and AgNO3 as an Ag+ ion source. Lack of AgNP interference with the cytotoxicity assays (AlamarBlue, CFDA-AM, NRU assay) and their simultaneous application point to the compatibility and usefulness of such a battery of assays. The RTH-149 and RTL-W1 liver cell lines exhibited similar sensitivity as primary hepatocytes towards AgNP toxicity. Leibovitz's L-15 culture medium composition (high amino acid content) had an important influence on the behaviour and toxicity of AgNPs towards the RTL-W1 cell line. The obtained results demonstrate that, with careful consideration, such an in vitro approach can provide valuable toxicological data to be used in an integrated testing strategy for NM-300K risk assessment.


Assuntos
Hepatócitos/efeitos dos fármacos , Nanopartículas/toxicidade , Oncorhynchus mykiss , Prata/toxicidade , Animais , Linhagem Celular
13.
Sci Total Environ ; 505: 253-60, 2015 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-25461026

RESUMO

Here we examined whether the addition of a non-toxic concentration (6.25 µg/mL) of zinc oxide nanoparticles (ZnONPs: 19, 35 and 57 nm, respectively) modulates the cytotoxicity of copper nanoparticles (CuNPs, 63 nm in size) in the human hepatoma cell line HepG2. The cytotoxic effect of CuNPs on HepG2 cells was markedly enhanced by the ZnONPs, the largest ZnONPs causing the highest increase in toxicity. However, CuNPs cytotoxicity was not affected by co-incubation with medium containing only zinc ions, indicating the increase in toxicity might be attributed to the particle form of ZnONPs. Transmission electron microscopy (TEM) revealed the presence of CuNPs and ZnONPs inside the cells co-exposed to both types of NP and outflow of cytoplasm through the damaged cell membrane. Inductively coupled plasma mass spectrometry (ICP-MS) determined an increase in the concentration of zinc and a decrease in that of copper in co-exposed cells. On the basis of these results, we propose that accumulation of large numbers of ZnONPs in the cells alters cellular membranes and the cytotoxicity of CuNPs is increased.


Assuntos
Cobre/toxicidade , Nanopartículas/toxicidade , Óxido de Zinco/toxicidade , Cobre/química , Técnicas In Vitro , Nanopartículas/química , Testes de Toxicidade , Óxido de Zinco/química
14.
Nanotoxicology ; 8(4): 383-93, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23600739

RESUMO

The four copper nanoparticles (CuNPs) with the size of 25, 50, 78 and 100 nm and one type of micron-sized particles (MPs) (~500 nm) were exposed to two mammalian (H4IIE and HepG2) and two piscine (PLHC-1 and RTH-149) cell lines to test the species-specific toxicities of CuNPs. The results showed that the morphologies, ion release and size of the particles all played an important role when investigating the toxicity. Furthermore, the authors found that the particle forms of CuNPs in suspensions highly contribute to the toxicity in all exposed cell lines whereas copper ions (Cu(2+)) only caused significant responses in mammalian cell lines, indicating the species-specific toxicity of CuNPs. This study revealed that the morphologies, ion release rate of NPs as well as the species-specific vulnerabilities of cells should all be considered when explaining and extrapolating toxicity test results among particles and among species.


Assuntos
Cobre/química , Cobre/toxicidade , Nanopartículas Metálicas/química , Nanopartículas Metálicas/toxicidade , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Fundulidae , Humanos , Oncorhynchus mykiss , Tamanho da Partícula , Ratos , Espécies Reativas de Oxigênio/análise , Espécies Reativas de Oxigênio/metabolismo
15.
Nanoscale Res Lett ; 8(1): 315, 2013 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-23829784

RESUMO

In this study, we explored the biocompatibility of Au nanoparticles (NPs) capped with peptide-biphenyl hybrid (PBH) ligands containing glycine (Gly), cysteine (Cys), tyrosine (Tyr), tryptophan (Trp) and methionine (Met) amino acids in the human hepatocellular carcinoma cell line Hep G2. Five AuNPs, Au[(Gly-Tyr-Met)2B], Au[(Gly-Trp-Met)2B], Au[(Met)2B], Au[(Gly-Tyr-TrCys)2B] and Au[(TrCys)2B], were synthesised. Physico-chemical and cytotoxic properties were thoroughly studied. Transmission electron micrographs showed isolated near-spherical nanoparticles with diameters of 1.5, 1.6, 2.3, 1.8 and 2.3 nm, respectively. Dynamic light scattering evidenced the high stability of suspensions in Milli-Q water and culture medium, particularly when supplemented with serum, showing in all cases a tendency to form agglomerates with diameters approximately 200 nm. In the cytotoxicity studies, interference caused by AuNPs with some typical cytotoxicity assays was demonstrated; thus, only data obtained from the resazurin based assay were used. After 48-h incubation, only concentrations ≥50 µg/ml exhibited cytotoxicity. Such doses were also responsible for an increase in reactive oxygen species (ROS). Some differences were observed among the studied NPs. Of particular importance is the AuNPs capped with the PBH ligand (Gly-Tyr-TrCys)2B showing remarkable stability in culture medium, even in the absence of serum. Moreover, these AuNPs have unique biological effects on Hep G2 cells while showing low toxicity. The production of ROS along with supporting optical microscopy images suggests cellular interaction/uptake of these particular AuNPs. Future research efforts should further test this hypothesis, as such interaction/uptake is highly relevant in drug delivery systems.

16.
Nanotoxicology ; 7(5): 935-52, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22417080

RESUMO

The increasing presence of ZnO nanoparticles (NPs) in consumer products may be having a dramatic impact in aquatic environments. The evaluation of ZnO NP toxicity represents a great challenge. This study aimed at evaluating the cytotoxic effect of micro- and nanosized ZnO in a fish and a mammalian hepatoma cell line. A detailed characterisation of the particles in exposure media showed that ZnO NPs formed large aggregates. ZnO cytotoxicity was evaluated with a battery of in vitro assays including LUCS, a new approach based on DNA alteration measurements. In fish cells, ZnO NP aggregates contributed substantially to the cytotoxic effects whereas toxicity in the human cells appeared to be mainly produced by the dissolved fraction. ROS production did not contribute to the observed cytotoxicity. This work also showed that measuring concentrations of NPs is essential to understand the mechanisms underlying their toxicity.


Assuntos
Nanopartículas Metálicas/química , Nanopartículas Metálicas/toxicidade , Óxido de Zinco/química , Óxido de Zinco/toxicidade , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Células Hep G2 , Humanos , L-Lactato Desidrogenase/metabolismo , Luz , Espectrometria de Massas , Vermelho Neutro/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Tamanho da Partícula , Poecilia , Espécies Reativas de Oxigênio/análise , Espécies Reativas de Oxigênio/metabolismo , Espalhamento de Radiação
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