Predictive value of in vitro assays depends on the mechanism of toxicity of metal oxide nanoparticles (original) (raw)
Related papers
PLOS ONE, 2015
Nanomaterials (NMs) display many unique and useful physico-chemical properties. However, reliable approaches are needed for risk assessment of NMs. The present study was performed in the FP7-MARINA project, with the objective to identify and evaluate in vitro test methods for toxicity assessment in order to facilitate the development of an intelligent testing strategy (ITS). Six representative oxide NMs provided by the EC-JRC Nanomaterials Repository were tested in nine laboratories. The in vitro toxicity of NMs was evaluated in 12 cellular models representing 6 different target organs/systems (immune system, respiratory system, gastrointestinal system, reproductive organs, kidney and embryonic tissues). The toxicity assessment was conducted using 10 different assays for cytotoxicity, embryotoxicity, epithelial integrity, cytokine secretion and oxidative stress. Thorough physico-chemical characterization was performed for all tested NMs. Commercially relevant NMs with different physico-chemical properties were selected: two TiO 2 NMs with different surface chemistryhydrophilic (NM-103) and hydrophobic (NM-104), two forms of and coated with triethoxycapryl silane (NM-111) and two SiO 2 NMs produced by two different manufacturing techniquesprecipitated (NM-200) and pyrogenic (NM-203). Cell specific toxicity effects of all NMs were observed; macrophages were the most sensitive cell type after short-term exposures (24-72h) (ZnO>SiO 2 >TiO 2 ). Longer term exposure (7 to 21 days) significantly affected the cell barrier integrity in the presence of ZnO, but not TiO 2 and SiO 2 , while the embryonic stem cell test (EST) classified the TiO 2 NMs as potentially 'weakembryotoxic' and ZnO and SiO 2 NMs as 'non-embryotoxic'. A hazard ranking could be established for the representative NMs tested (ZnO NM-110 > ZnO NM-111 > SiO 2 NM-203 > SiO 2 NM-200 > TiO 2 NM-104 > TiO 2 NM-103). This ranking was different in the case of embryonic tissues, for which TiO 2 displayed higher toxicity compared with ZnO and SiO 2 . Importantly, the in vitro methodology applied could identify cell-and NM-specific responses, with a low variability observed between different test assays. Overall, this testing approach, based on a battery of cellular systems and test assays, complemented by an exhaustive physico-chemical characterization of NMs, could be deployed for the development of an ITS suitable for risk assessment of NMs. This study also provides a rich source of data for modeling of NM effects.
Particle and Fibre Toxicology, 2014
Background: Although ZnO nanoparticles (NPs) are used in many commercial products and the potential for human exposure is increasing, few in vivo studies have addressed their possible toxic effects after inhalation. We sought to determine whether ZnO NPs induce pulmonary toxicity in mice following sub-acute or sub-chronic inhalation exposure to realistic exposure doses. Methods: Mice (C57Bl/6) were exposed to well-characterized ZnO NPs (3.5 mg/m 3 , 4 hr/day) for 2 (sub-acute) or 13 (sub-chronic) weeks and necropsied immediately (0 wk) or 3 weeks (3 wks) post exposure. Toxicity was assessed by enumeration of total and differential cells, determination of total protein, lactate dehydrogenase activity and inflammatory cytokines in bronchoalveolar lavage (BAL) fluid as well as measurements of pulmonary mechanics. Generation of reactive oxygen species was assessed in the lungs. Lungs were evaluated for histopathologic changes and Zn content. Zn concentration in blood, liver, kidney, spleen, heart, brain and BAL fluid was measured. Results: An elevated concentration of Zn 2+ was detected in BAL fluid immediately after exposures, but returned to baseline levels 3 wks post exposure. Dissolution studies showed that ZnO NPs readily dissolved in artificial lysosomal fluid (pH 4.5), but formed aggregates and precipitates in artificial interstitial fluid (pH 7.4). Sub-acute exposure to ZnO NPs caused an increase of macrophages in BAL fluid and a moderate increase in IL-12(p40) and MIP-1α, but no other inflammatory or toxic responses were observed. Following both sub-acute and sub-chronic exposures, pulmonary mechanics were no different than sham-exposed animals. Conclusions: Our ZnO NP inhalation studies showed minimal pulmonary inflammation, cytotoxicity or lung histopathologic changes. An elevated concentration of Zn in the lung and BAL fluid indicates dissolution of ZnO NPs in the respiratory system after inhalation. Exposure concentration, exposure mode and time post exposure played an important role in the toxicity of ZnO NPs. Exposure for 13 wks with a cumulative dose of 10.9 mg/kg yielded increased lung cellularity, but other markers of toxicity did not differ from sham-exposed animals, leading to the conclusion that ZnO NPs have low sub-chronic toxicity by the inhalation route.
A practical approach to assess inhalation toxicity of metal oxide nanoparticles in vitro
Journal of applied toxicology : JAT, 2018
Exposure of humans to metal oxide nanoparticles (NPs) occurs mainly via air, and inhaled metal oxide NPs may generate inflammation. The aim of this study was to investigate the proinflammatory potential of six metal oxide NPs (CeO , Mn O , CuO, ZnO, Co O and WO ; 27-108 μg ml ) using human primary 3-dimensional airway epithelium (MucilAir™) and dendritic cell (DC) models. Metal oxide NPs were mainly aggregated/agglomerated in the cell media, as determined by dynamic light scattering, scanning electron microscopy and differential centrifugal sedimentation. WO and ZnO were highly soluble, both with and without respiratory mucus. Proinflammatory signalling by the epithelium was evaluated after a 24 hour exposure by increased interleukin-6 and -8 and monocyte chemoattractant protein 1 cytokine release, which occurred only for CuO. Moreover, maturation of immature human DCs, which play a key role in the lung immune system, were evaluated by expression of surface markers HLA-DR, CD80, CD8...
A review of mammalian toxicity of ZnO nanoparticles
Nanotechnology, Science and Applications, 2012
This review summarizes the literature on mammalian toxicity of ZnO nanoparticles (NPs) published between 2009 and 2011. The toxic effects of ZnO NPs are due to the compound's solubility. Whether the increased intracellular [Zn(2+)] is due to the NPs being taken up by cells or to NP dissolution in medium is still unclear. In vivo airway exposure poses an important hazard. Inhalation or instillation of the NPs results in lung inflammation and systemic toxicity. Reactive oxygen species (ROS) generation likely plays an important role in the inflammatory response. The NPs do not, or only to a minimal extent, cross the skin; this also holds for sunburned skin. Intraperitoneal administration induces neurological effects. The NPs show systemic distribution; target organs are liver, spleen, lung, and kidney and, in some cases, the heart. In vitro exposure of BEAS-2B bronchial epithelial cells and A549 alveolar adenocarcinoma cells results in cytotoxicity, increased oxidative stress, increased intracellular [Ca(2+)], decreased mitochondrial membrane potential, and interleukin (IL)-8 production. Decreased contractility of airway smooth muscle cells poses an additional hazard. In contrast to the results for BEAS-2B and A549 cells, in RKO colon carcinoma cells ZnO NPs and not Zn(2+) induce cytotoxicity and mitochondrial dysfunction. Short-term exposure of skin cells results in apoptosis but not in an inflammatory response, while long-term exposure leads to increased ROS generation, decreased mitochondrial activity, and formation of tubular intercellular structures. Macrophages, monocytes, and dendritic cells are affected; exposure results in cytotoxicity, oxidative stress, intracellular Ca(2+) flux, decreased mitochondrial membrane potential, and production of IL-1β and chemokine CXCL9. The NPs are phagocytosed by macrophages and dissolved in lysosomes. In vitro the Comet assay and the cytokinesis-blocked micronucleus assay show genotoxicity, whereas the Ames test does not. This is, however, not confirmed by in vivo genotoxicity assays. Protein binding results in increased stability.
Particle and Fibre Toxicology
Background Acute phase response (APR) is characterized by a change in concentration of different proteins, including C-reactive protein and serum amyloid A (SAA) that can be linked to both exposure to metal oxide nanomaterials and risk of cardiovascular diseases. In this study, we intratracheally exposed mice to ZnO, CuO, Al2O3, SnO2 and TiO2 and carbon black (Printex 90) nanomaterials with a wide range in phagolysosomal solubility. We subsequently assessed neutrophil numbers, protein and lactate dehydrogenase activity in bronchoalveolar lavage fluid, Saa3 and Saa1 mRNA levels in lung and liver tissue, respectively, and SAA3 and SAA1/2 in plasma. Endpoints were analyzed 1 and 28 days after exposure, including histopathology of lung and liver tissues. Results All nanomaterials induced pulmonary inflammation after 1 day, and exposure to ZnO, CuO, SnO2, TiO2 and Printex 90 increased Saa3 mRNA levels in lungs and Saa1 mRNA levels in liver. Additionally, CuO, SnO2, TiO2 and Printex 90 in...
Nanotoxicology, 2016
Metal oxide nanoparticles are used in a broad range of industrial processes and workers may be exposed to aerosols of the particles both during production and handling. Despite the widespread use of these particles, relatively few studies have been performed to investigate the toxicological effects in the airways following inhalation. In the present study, the acute (24 h) and persistent (13 weeks) effects in the airways after a single exposure to metal oxide nanoparticles were studied using a murine inhalation model. Mice were exposed 60 min to aerosols of either ZnO, TiO 2 , Al 2 O 3 or CeO 2 and the deposited doses in the upper and lower respiratory tracts were calculated. Endpoints were acute airway irritation, pulmonary inflammation based on analyses of bronchoalveolar lavage (BAL) cell composition, DNA damage assessed by the comet assay and pulmonary toxicity assessed by protein level in BAL fluid and histology. All studied particles reduced the tidal volume in a concentration-dependent manner accompanied with an increase in the respiratory rate. In addition, ZnO and TiO 2 induced nasal irritation. BAL cell analyses revealed both neutrophilic and lymphocytic inflammation 24-h postexposure to all particles except TiO 2 . The ranking of potency regarding induction of acute lung inflammation was Al 2 O 3 ¼ TiO 2 5CeO 2 ( ZnO. Exposure to CeO 2 gave rise to a more persistent inflammation; both neutrophilic and lymphocytic inflammation was seen 13 weeks after exposure. As the only particles, ZnO caused a significant toxic effect in the airways while TiO 2 gave rise to DNA-strand break as shown by the comet assay.
Toxicology and Applied Pharmacology, 2014
The applicability of rat precision-cut lung slices (PCLuS) in detecting nanomaterial (NM) toxicity to the respiratory tract was investigated evaluating sixteen OECD reference NMs (TiO 2 , ZnO, CeO 2 , SiO 2 , Ag, multi-walled carbon nanotubes (MWCNTMWCNTs)). Upon 24-hour test substance exposure, the PCLuS system was able to detect early events of NM toxicity: total protein, reduction in mitochondrial activity, caspase-3/-7 activation, glutathione depletion/increase, cytokine induction, and histopathological evaluation. Ion shedding NMS (ZnO and Ag) induced severe tissue destruction detected by the loss of total protein. Two anatase TiO 2 NMs, CeO 2 NMs, and two MWCNT caused significant (determined by trend analysis) cytotoxicity in the WST-1 assay. At non-cytotoxic concentrations, different TiO 2 NMs and one MWCNT increased GSH levels, presumably a elsevier_YTAAP_12991 defence defense response to reactive oxygen species, and these substances further induced a variety of cytokines. One of the SiO 2 NMs increased caspase-3/-7 activities at non-cytotoxic levels, and one rutile TiO 2 only induced cytokines. Investigating these effects is, however, not sufficient to predict apical effects found in vivo. Reproducibility of test substance measurements was not fully satisfactory, especially in the GSH and cytokine assays.
Nanotoxicology, 2013
There are a multitude of nanoparticles (NPs) which have shown great potentials for medical applications. A few of them are already used for lung therapeutic and diagnostic purposes. However, there are few toxicological studies which determine possible adverse pulmonary responses. It is thus important to propose in vitro screening strategies to evaluate the pulmonary toxicity of NPs used in nanomedicine. Our goal was to determine the cellular effects of several biomedical NPs with different physico-chemical characteristics (chemical nature, size and coating) to establish suitable tests and useful benchmark NPs. The effects of poly(lacticco-glycolic acid) (PLGA), silica, iron oxide and titanium dioxide NPs were studied using human bronchial (16HBE) and alveolar epithelial cells (A549). We evaluated cytotoxicity, reactive oxygen species (ROS) production and pro-inflammatory response in both cell lines. We demonstrated that PLGA NPs are good candidates for negative control NPs and SiO 2 NPs were revealed to be the best benchmark NPs. Coating of Fe 3 O 4 with sodium oleate, a known biocompatible compound, led to an unexpected increase in cytotoxicity. Moreover, 16HBE cells are more sensitive than A549 cells and propidium iodide uptake is a more sensitive cytotoxicity test than WST-1. The measurement of oxidative stress does not systematically allow us to predict cellular responses and different other cellular endpoints should also be addressed. We conclude that a battery of assays and cell lines are necessary to accurately evaluate the pulmonary effects of NPs and that PLGA and SiO 2 NPs are suitable candidates respectively for negative and positive controls.
Environmental Health Perspectives, 2008
Nanotechnologies have the potential to improve many aspects of our life. Nanomaterials are either being used or have the potential to be widely incorporated in a range of applications, including textiles, finishes, and electronics, as well as having a spectrum of uses in medical imaging, disease diagnoses, and drug delivery. This potential is a result of unique physicochemical characteristics apparent at the nanoscale, such as large surface area, altered electronic properties, surface reactiv
Comparative effects of metal oxide nanoparticles on human airway epithelial cells and macrophages
Journal of Nanoparticle Research, 2012
Among nanomaterials of industrial relevance, metal-based nanoparticles (NPs) are widely used, but their effects on airway cells are relatively poorly characterized. To compare the effects of metal NPs on cells representative of the lung-blood barrier, Calu-3 epithelial cells and Raw264.7 macrophages were incubated with three industrially relevant preparations of TiO 2 NPs (size range 4-33 nm), two preparations of CeO 2 NPs (9-36 nm) and CuO NPs (25 nm). While Raw264.7 were grown on standard plasticware, Calu-3 cells were seeded on permeable filters, where they form a high-resistance monolayer, providing an in vitro model of the airway barrier. Metal NPs, obtained from industrial sources, were characterized under the conditions adopted for the biological tests. Cytotoxicity was assessed with resazurin method in both epithelial and macrophage cells, while epithelial barrier permeability was monitored measuring the trans-epithelial electrical resistance (TEER). In macrophages, titania and ceria had no significant effect on viability in the whole range of nominal doses tested (15-240 lg/cm 2 of monolayer), while CuO NPs produced a marked viability loss. Moreover, only CuO NPs, but not the other NPs, lowered TEER of Calu-3 monolayers, pointing to the impairment of the epithelial barrier. TEER decreased by 30 % at the dose of 10 lg/cm 2 of CuO NPs, compared to untreated control, and was abolished at doses C80 lg/cm 2 , in strict correlation with changes in cell viability. These results indicate that (1) CuO NPs increase airway epithelium permeability even at relatively low doses and are significantly toxic for macrophages and airway epithelial cells, likely through the release of Cu ions in the medium; (2) TiO 2 and CeO 2 NPs do not affect TEER and exhibit little acute toxicity for airway epithelial cells and macrophages; and (3) TEER measurement can provide a simple method to assess the impairment
Toxicological Sciences, 2012
The toxicology of nanoparticles (NPs) is an area of intense investigation that would be greatly aided by improved understanding of the relationship between NP structure and inflammogenicity. To evaluate how their physicochemical parameters influence toxicity, we assembled a panel of 15 metal/metal oxide NPs and attempted to relate various physicochemical parameters, including zeta potential (zP) and solubility, to lung inflammogenicity. The acute pulmonary inflammogenicity of the 15 NPs showed a significant correlation with one of two structural parameters-zP under acid conditions for low-solubility NPs and solubility to toxic species for high-solubility NPs. zP is the electrical potential created between the surface of a particle, with its associated ions, and the medium it exists in and provides information concerning the particle surface charge. We suggest that inside the phagolysosome under acid conditions, a high positive zP may allow NPs to damage the integrity of the phagolysosomal membrane leading to inflammation. In the case of high-solubility NPs, inflammogenicity depends on the ions that are produced during dissolution of NP inside the acidic phagolysosomes; if the ions are toxic, then phagolysosomes will be destabilized and cause inflammation. These two parameters may have utility in preliminary assessment of the potential lung inflammation hazard of the large number of NPs that require testing.
Food and Chemical Toxicology, 2015
Inhalation is the main pathway of ZnO exposure in the occupational environment but only few studies have addressed toxic effects after pulmonary exposure to ZnO nanoparticles (NP). Here we present results from three studies of pulmonary exposure and toxicity of ZnO NP in mice. The studies were prematurely terminated because interim results unexpectedly showed severe pulmonary toxicity. High bolus doses of ZnO NP (25 up to 100 mg; !1.4 mg/kg) were clearly associated with a dose dependent mortality in the mice. Lower doses (!6 mg; !0.3 mg/kg) elicited acute toxicity in terms of reduced weight gain, desquamation of epithelial cells with concomitantly increased barrier permeability of the alveolar/ blood as well as DNA damage. Oxidative stress was shown via a strong increase in lipid peroxidation and reduced glutathione in the pulmonary tissue. Two months post-exposure revealed no obvious toxicity for 12.5 and 25 mg on a range of parameters. However, mice that survived a high dose (50 mg; 2.7 mg/kg) had an increased pulmonary collagen accumulation (fibrosis) at a similar level as a high bolus dose of crystalline silica. The recovery from these toxicological effects appeared dose-dependent. The results indicate that alveolar deposition of ZnO NP may cause significant adverse health effects.
Acute Inflammatory Responses of Nanoparticles in an Intra-Tracheal Instillation Rat Model
PLOS ONE, 2015
Exposure to hard metal tungsten carbide cobalt (WC-Co) "dusts" in enclosed industrial environments is known to contribute to the development of hard metal lung disease and an increased risk for lung cancer. Currently, the influence of local and systemic inflammation on disease progression following WC-Co exposure remains unclear. To better understand the relationship between WC-Co nanoparticle (NP) exposure and its resultant effects, the acute local pulmonary and systemic inflammatory responses caused by WC-Co NPs were explored using an intra-tracheal instillation (IT) model and compared to those of CeO 2 (another occupational hazard) NP exposure. Sprague-Dawley rats were given an IT dose (0-500 μg per rat) of WC-Co or CeO 2 NPs. Following 24-hr exposure, broncho-alveolar lavage fluid and whole blood were collected and analyzed. A consistent lack of acute local pulmonary inflammation was observed in terms of the broncho-alveolar lavage fluid parameters examined (i.e. LDH, albumin, and macrophage activation) in animals exposed to WC-Co NP; however, significant acute pulmonary inflammation was observed in the CeO 2 NP group. The lack of acute inflammation following WC-Co NP exposure contrasts with earlier in vivo reports regarding WC-Co toxicity in rats, illuminating the critical role of NP dose and exposure time and bringing into question the potential role of impurities in particle samples. Further, we demonstrated that WC-Co NP exposure does not induce acute systemic effects since no significant increase in circulating inflammatory cytokines were observed. Taken together, the results of this in vivo study illustrate the distinct differences in acute local pulmonary and systemic inflammatory responses to NPs composed of WC-Co and CeO 2 ; PLOS ONE |
Future Science OA, 2016
Nanoparticles (Nps) can induce toxicity in the lung by accidental or intentional exposure. The main objective of the study reported here was to characterize the effect that four metal oxide Nps (CeO2, TiO2, Al2O3 and ZnO) had at the cellular level on a human lung epithelial cell line. This goal was achieved by studying the capacity of the Nps to activate the main mitogen-activated protein kinases (MAPKs) and the nuclear factor NFκB. Only ZnO Nps were able to activate all of the MAPKs and the release of Zn2+ ions was the main cause of activation. ZnO and Al2O3 Nps activated the NFκB pathway and induced the release of inflammatory cytokines. CeO2 and TiO2 Nps were found to have safer profiles. [Formula: see text] The graphical abstract was obtained using Servier Medical Art.
Toxicity of 11 Metal Oxide Nanoparticles to Three Mammalian Cell Types In V.itro
Current Topics in Medicinal Chemistry, 2015
The knowledge on potential harmful effects of metallic nanomaterials lags behind their increased use in consumer products and therefore, the safety data on various nanomaterials applicable for risk assessment are urgently needed. In this study, 11 metal oxide nanoparticles (MeOx NPs) prepared using flame pyrolysis method were analyzed for their toxicity against human alveolar epithelial cells A549, human epithelial colorectal cells Caco2 and murine fibroblast cell line Balb/c 3T3. The cell lines were exposed for 24 h to suspensions of 3-100 µg/mL MeOx NPs and cellular viability was evaluated using. Neutral Red Uptake (NRU) assay. In parallel to NPs, toxicity of soluble salts of respective metals was analyzed, to reveal the possible cellular effects of metal ions shedding from the NPs. The potency of MeOx to produce reactive oxygen species was evaluated in the cell-free assay. The used three cell lines showed comparable toxicity responses to NPs and their metal ion counterparts in the current test setting. Six MeOx NPs (Al 2 O 3 , Fe 3 O 4 , MgO, SiO 2 , TiO 2 , WO 3 ) did not show toxic effects below 100 µg/mL. For five MeOx NPs, the averaged 24 h IC 50 values for the three mammalian cell lines were 16.4 µg/mL for CuO, 22.4 µg/mL for ZnO, 57.3 µg/mL for Sb 2 O 3 , 132.3 µg/mL for Mn 3 O 4 and 129 µg/mL for Co 3 O 4 . Comparison of the dissolution level of MeOx and the toxicity of soluble salts allowed to conclude that the toxicity of CuO, ZnO and Sb 2 O 3 NPs was driven by release of metal ions. The toxic effects of Mn 3 O 4 and Co 3 O 4 could be attributed to the ROS-inducing ability of these NPs. All the NPs were internalized by the cells according to light microscopy studies but also proven by TEM, and internalization of Co 3 O 4 NPs seemed to be most prominent in this aspect. In conclusion, this work provides valuable toxicological data for a library of 11 MeOx NPs. Combining the knowledge on toxic or non-toxic nature of nanomaterials may be used for safe-by-design approach.
In Vitro Cytotoxicity Assessment of Metal Oxide Nanoparticles
Nanomedicine and Nanobiology, 2014
Nanotechnology has raised concern about inert substances (bulk) that becomes toxic at nano-level. Impact of nanoparticles toxicity on human body has been described by researchers but detailed mechanism on different organ system is still unknown. Our objective is to assess the toxicity of Metal oxide NPs (used in military armaments) e.g., Zinc Oxide (ZnO), Tungsten oxide (WO 3 , Titanium Oxide (TiO 2 , Cobalt oxide (CoO 4 and Aluminum oxide (Al 2 O 3 on mammalian lung, macrophages, skin and liver cell lines. Nanoparticles (NPs) impact was assessed on human cells exposed to different NPs concentrations (1-1000 g) and time points (2-72 hrs). Mitochondrial functionality, cell viability, uptake of NPs, Reactive Oxygen Species (ROS) generation, inflammatory response and genotoxicity were evaluated as cellular endpoints. Size and uniformity of NP dispersion was assessed by Dynamic Light Scattering. ZnO NPs were found to be toxic at all conc. As compared to others being minimal. ZnO treated lung cells displayed increased DNA damage and high ROS generation as compared to other NPs. Our study indicates that metal oxide induce ROS and oxidative stress leading to DNA damage (probable mechanism of toxicity).
Toxicity of 11 Metal Oxide Nanoparticles to Three Mammalian Cell Types In Vitro
The knowledge on potential harmful effects of metallic nanomaterials lags behind their increased use in consumer products and therefore, the safety data on various nanomaterials applicable for risk assessment are urgently needed. In this study, 11 metal oxide nanoparticles (MeOx NPs) prepared using flame pyrolysis method were analyzed for their toxicity against human alveolar epithelial cells A549, human epithelial colorectal cells Caco2 and murine fibroblast cell line Balb/c 3T3. The cell lines were exposed for 24 h to suspensions of 3-100 μg/mL MeOx NPs and cellular viability was evaluated using. Neutral Red Uptake (NRU) assay. In parallel to NPs, toxicity of soluble salts of respective metals was analyzed, to reveal the possible cellular effects of metal ions shedding from the NPs. The potency of MeOx to produce reactive oxygen species was evaluated in the cell-free assay. The used three cell lines showed comparable toxicity responses to NPs and their metal ion counterparts in the current test setting. Six MeOx NPs (Al 2 O 3 , Fe 3 O 4 , MgO, SiO 2 , TiO 2 , WO 3) did not show toxic effects below 100 μg/mL. For five MeOx NPs, the averaged 24 h IC 50 values for the three mammalian cell lines were 16.4 μg/mL for CuO, 22.4 μg/mL for ZnO, 57.3 μg/mL for Sb 2 O 3 , 132.3 μg/mL for Mn 3 O 4 and 129 μg/mL for Co 3 O 4. Comparison of the dissolution level of MeOx and the toxicity of soluble salts allowed to conclude that the toxicity of CuO, ZnO and Sb 2 O 3 NPs was driven by release of metal ions. The toxic effects of Mn 3 O 4 and Co 3 O 4 could be attributed to the ROS-inducing ability of these NPs. All the NPs were internalized by the cells according to light microscopy studies but also proven by TEM, and internalization of Co 3 O 4 NPs seemed to be most prominent in this aspect. In conclusion, this work provides valuable toxicological data for a library of 11 MeOx NPs. Combining the knowledge on toxic or non-toxic nature of nanomaterials may be used for safe-by-design approach.
Journal of Nanobiotechnology, 2015
Background: This study evaluates the time-dependent pro-inflammatory response of the model human lung epithelial cells (A549) to industrially relevant zinc oxide nanoparticles (ZnO NPs). In terms of toxicity, ZnO-NPs are categorised into the group of high toxicity nanomaterials. However information on pro-inflammatory potential of these NPs at sub-toxic concentrations is limited. Understanding how cellular defense mechanisms function in the presence of sub-cytotoxic concentrations of these NPs is vital. Moreover, there is an urgent need for additional in vivo studies addressing pulmonary toxicity due to accidental inhalation of ZnO NPs.
Cited by
PLOS ONE, 2015
Nanomaterials (NMs) display many unique and useful physico-chemical properties. However, reliable approaches are needed for risk assessment of NMs. The present study was performed in the FP7-MARINA project, with the objective to identify and evaluate in vitro test methods for toxicity assessment in order to facilitate the development of an intelligent testing strategy (ITS). Six representative oxide NMs provided by the EC-JRC Nanomaterials Repository were tested in nine laboratories. The in vitro toxicity of NMs was evaluated in 12 cellular models representing 6 different target organs/systems (immune system, respiratory system, gastrointestinal system, reproductive organs, kidney and embryonic tissues). The toxicity assessment was conducted using 10 different assays for cytotoxicity, embryotoxicity, epithelial integrity, cytokine secretion and oxidative stress. Thorough physico-chemical characterization was performed for all tested NMs. Commercially relevant NMs with different physico-chemical properties were selected: two TiO 2 NMs with different surface chemistryhydrophilic (NM-103) and hydrophobic (NM-104), two forms of and coated with triethoxycapryl silane (NM-111) and two SiO 2 NMs produced by two different manufacturing techniquesprecipitated (NM-200) and pyrogenic (NM-203). Cell specific toxicity effects of all NMs were observed; macrophages were the most sensitive cell type after short-term exposures (24-72h) (ZnO>SiO 2 >TiO 2 ). Longer term exposure (7 to 21 days) significantly affected the cell barrier integrity in the presence of ZnO, but not TiO 2 and SiO 2 , while the embryonic stem cell test (EST) classified the TiO 2 NMs as potentially 'weakembryotoxic' and ZnO and SiO 2 NMs as 'non-embryotoxic'. A hazard ranking could be established for the representative NMs tested (ZnO NM-110 > ZnO NM-111 > SiO 2 NM-203 > SiO 2 NM-200 > TiO 2 NM-104 > TiO 2 NM-103). This ranking was different in the case of embryonic tissues, for which TiO 2 displayed higher toxicity compared with ZnO and SiO 2 . Importantly, the in vitro methodology applied could identify cell-and NM-specific responses, with a low variability observed between different test assays. Overall, this testing approach, based on a battery of cellular systems and test assays, complemented by an exhaustive physico-chemical characterization of NMs, could be deployed for the development of an ITS suitable for risk assessment of NMs. This study also provides a rich source of data for modeling of NM effects.
Biomolecules, 2015
Inflammation is considered to play a central role in a diverse range of disease outcomes associated with exposure to various types of inhalable particulates. The initial mechanisms through which particles trigger cellular responses leading to activation of inflammatory responses are crucial to clarify in order to understand what physico-chemical characteristics govern the inflammogenic activity of particulate matter and why some particles are more harmful than others. Recent research suggests that molecular triggering mechanisms involved in activation of proinflammatory genes and onset of inflammatory reactions by particles or soluble particle components can be categorized into direct formation of reactive oxygen species (ROS) with subsequent oxidative stress, interaction with the lipid layer of cellular membranes, activation of cell surface receptors, and direct interactions with intracellular molecular targets. The present review focuses on the immediate effects and responses in cells exposed to particles and central down-stream signaling mechanisms involved in regulation of proinflammatory genes, with special emphasis on the role of oxidant and non-oxidant triggering mechanisms. Importantly, ROS act as a central second-messenger in a variety of signaling pathways. Even non-oxidant mediated triggering mechanisms are therefore also likely to activate downstream redox-regulated events.
Safety assessment of nanomaterials using an advanced decision-making framework, the DF4nanoGrouping
Journal of Nanoparticle Research
Centre for Ecotoxicology and Toxicology of Chemicals (ECETOC) 'Nano Task Force' proposes a Decision-making framework for the grouping and testing of nanomaterials (DF4nanoGrouping) consisting of three tiers to assign nanomaterials to four main groups with possible further subgrouping to refine specific information needs. The DF4nanoGrouping covers all relevant aspects of a nanomaterial's life cycle and biological pathways: intrinsic material properties and system-dependent properties (that depend upon the nanomaterial's respective surroundings), biopersistence, uptake and biodistribution, and cellular and apical toxic effects. Use, release, and exposure route may be applied as 'qualifiers' to determine if, e.g., nanomaterials cannot be released from products, which may justify waiving of testing. The four main groups encompass (1) soluble, (2) biopersistent high aspect ratio, (3) passive, and (4) active nanomaterials. The DF4nanoGrouping foresees a stepwise evaluation of nanomaterial properties and effects with increasing biological complexity. In case studies covering carbonaceous nanomaterials, metal oxide, and metal sulfate nanomaterials, amorphous silica and organic pigments (all nanomaterials having primary particle sizes below 100 nm), the usefulness of the DF4nanoGrouping for nanomaterial hazard assessment was confirmed. The DF4nanoGrouping facilitates grouping and targeted testing of nanomaterials. It ensures that sufficient data for the risk assessment of a nanomaterial are available, and it fosters the use of non-animal methods. No studies are performed that do not provide crucial data. Thereby, the DF4nanoGrouping serves to save both animals and resources. Keywords Grouping. Hazard and risk assessment. Realistic exposure scenarios. Integrated approach for testing and assessment (IATA). In vitro effects. Nanomaterials. Societal implications
Frontiers in Pharmacology
The main mechanism of toxicity for fast-dissolving nanoparticles (NPs) is relatively simple as it originates from the intrinsic toxicity of their constituent elements rather than complicated surface reactivity. However, there is little information about the compared toxicity of fast-dissolving NP and its constituent ion, which is essential for understanding the mechanism of NP toxicity and the development of a structure-toxicity relationship (STR) model. Herein, we selected three types of fast-dissolving metaloxide NPs (CoO, CuO, and ZnO) and constituent metal chlorides (CoCl 2 , CuCl 2 , and ZnCl 2) to compare dose-response curves between NP and its constituent metal. These materials were treated relevant cell lines for inhalation setting (i.e., differentiated THP-1 cells for macrophages and A549 cells for alveolar epithelial cells) and cytotoxicity as an endpoint was evaluated at 24 h post-incubation. The results showed that CoO and CuO NPs in both cell types showed similar patterns of dose-response curves and cytotoxic potential compared to that of their respective metal chloride. On the other hand, ZnO NPs in both cell types showed a completely different dose-response curve compared to that of ZnCl 2 : ZnO NPs showed modest slope and much less potential for cytotoxicity compared to that of ZnCl 2. These results imply that fastdissolving metal-oxide NPs are not always have similar dose-response curves and toxic potentials compared to their constituent metal chlorides and this may be due to the differential mechanism of intracellular uptake of these substances and their interaction with intracellular detoxification molecules. Further investigations are needed for the use of toxic potential of metal ions as a predicting factors of fast-dissolving NPs toxicity. In addition, chelating agent specific for dissolved metal ions can be applied for the treatment of these fast-dissolving NPs.
Biological interactions in vitro of zinc oxide nanoparticles of different characteristics
Materials Research Express, 2014
Zinc oxide nanoparticles (ZnO NPs) have recently received growing attention for various biomedical applications, including use as therapeutic or carrier for drug delivery and/or imaging. For the above applications, the NPs necessitate administration into the body leading to their systemic exposure. To better anticipate the safety, make risk assessment, and be able to interpret the future preclinical and clinical safety data, it is important to systematically understand the biological interaction of the NPs, the consequences of such interaction, and the mechanisms associated with the toxicity induction, with the important components with which the NPs are expected to be in contact after systemic exposure. In this context, we report here a detailed study on the biological interactions in vitro of the ZnO NPs with healthy human primary lymphocytes as these are the important immune components and the first systemic immune contact, and with the whole human blood. Additionally, the influence, if any, of the NPs shape (spheres and rods) on the biological interaction has been evaluated. The ZnO NPs caused toxicity (30% at 12.5 μg ml −1 spheres and 10.5 μg ml −1 rods; 50% at 22 μg ml −1 spheres and 19.5 μg ml −1 rods) to the lymphocytes at molecular and genetic level in a dose-dependent and shapedependent manner, while the interaction consequences with the blood and blood components such as RBC, platelets was only dose-dependent and not shapedependent. This is evident from the decreased RBC count due to increased %
In Vitro and In Vivo Short-Term Pulmonary Toxicity of Differently Sized Colloidal Amorphous SiO₂
Nanomaterials (Basel, Switzerland), 2018
In vitro prediction of inflammatory lung effects of well-dispersed nanomaterials is challenging. Here, the in vitro effects of four colloidal amorphous SiO₂ nanomaterials that differed only by their primary particle size (9, 15, 30, and 55 nm) were analyzed using the rat NR8383 alveolar macrophage (AM) assay. Data were compared to effects of single doses of 15 nm and 55 nm SiO₂ intratracheally instilled in rat lungs. In vitro, all four elicited the release of concentration-dependent lactate dehydrogenase, β-glucuronidase, and tumor necrosis factor alpha, and the two smaller materials also released H₂O₂. All effects were size-dependent. Since the colloidal SiO₂ remained well-dispersed in serum-free in vitro conditions, effective particle concentrations reaching the cells were estimated using different models. Evaluating the effective concentration-based in vitro effects using the Decision-making framework for the grouping and testing of nanomaterials, all four nanomaterials were assi...
Synthesis of Nylon 6/Modified Carbon Black Nanocomposites for Application in Uric Acid Adsorption
Materials
High uric acid levels cause different clinic conditions. One of them is hyperuricemia, which leads to kidney damage. A solution for eliminating uric acid in the blood is by hemodialysis, which is performed using nanocomposite membranes. In this work, Nylon 6 nanocomposites were synthesized with modified carbon black (MCB), which were considered candidate materials for hemodialysis membranes. The modification of carbon black was made with citric acid using the variable-frequency ultrasound method. The new MCB was characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), transmission electron microscopy (TEM), and dispersion tests. Nylon 6/MCB nanocomposites were processed using the ultrasound-assisted melt-extrusion method to improve the dispersion procedure of the nanoparticles. The Nylon 6/MCB nanocomposites were characterized by FTIR, TGA, and differential scanning calorimetry (DSC). These were assessed for the abso...
Nanomaterials
Synthetic amorphous silica (SAS) constitute a large group of industrial nanomaterials (NM). Based on their different production processes, SAS can be distinguished as precipitated, fumed, gel and colloidal. The biological activity of SAS, e.g., cytotoxicity or inflammatory potential in the lungs is low but has been shown to depend on the particle size, at least for colloidal silica. Therefore, the preparation of suspensions from highly aggregated or agglomerated SAS powder materials is critical. Here we analyzed the influence of ultrasonic dispersion energy on the biologic activity of SAS using NR8383 alveolar macrophage (AM) assay. Fully characterized SAS (7 precipitated, 3 fumed, 3 gel, and 1 colloidal) were dispersed in H2O by stirring and filtering through a 5 µm filter. Aqueous suspensions were sonicated with low or high ultrasonic dispersion (USD) energy of 18 or 270 kJ/mL, respectively. A dose range of 11.25–90 µg/mL was administered to the AM under protein-free conditions to...
Nanomaterials
Various cell types are compromised by synthetic amorphous silica (SAS) if they are exposed to SAS under protein-free conditions in vitro. Addition of serum protein can mitigate most SAS effects, but it is not clear whether this is solely caused by protein corona formation and/or altered particle uptake. Because sensitive and reliable mass spectrometric measurements of SiO2 NP are cumbersome, quantitative uptake studies of SAS at the cellular level are largely missing. In this study, we combined the comparison of SAS effects on alveolar macrophages in the presence and absence of foetal calf serum with mass spectrometric measurement of 28Si in alkaline cell lysates. Effects on the release of lactate dehydrogenase, glucuronidase, TNFα and H2O2 of precipitated (SIPERNAT® 50, SIPERNAT® 160) and fumed SAS (AEROSIL® OX50, AEROSIL® 380 F) were lowered close to control level by foetal calf serum (FCS) added to the medium. Using a quantitative high resolution ICP-MS measurement combined with ...
Nanomaterials
Relevant in vitro assays that can simulate exposure to nanoparticles (NPs) via inhalation are urgently needed. Presently, the most common method employed is to expose lung cells under submerged conditions, but the cellular responses to NPs under such conditions might differ from those observed at the more physiological air-liquid interface (ALI). The aim of this study was to investigate the cytotoxic and inflammatory potential of CeO2 NPs (NM-212) in a co-culture of A549 lung epithelial cells and differentiated THP-1 cells in both ALI and submerged conditions. Cellular dose was examined quantitatively using inductively coupled plasma mass spectrometry (ICP-MS). The role of serum and LPS-priming for IL-1β release was further tested in THP-1 cells in submerged exposure. An aerosol of CeO2 NPs was generated by using the PreciseInhale® system, and NPs were deposited on the co-culture using XposeALI®. No or minor cytotoxicity and no increased release of inflammatory cytokines (IL-1β, IL-...
Nanobiomedicine
Current antiretroviral drugs used to prevent or treat human immunodeficiency virus type 1 (HIV-1) infection are not able to eliminate the virus within tissues or cells where HIV establishes reservoirs. Hence, there is an urgent need to develop targeted delivery systems to enhance drug concentrations in these viral sanctuary sites. Macrophages are key players in HIV infection and contribute significantly to the cellular reservoirs of HIV because the virus can survive for prolonged periods in these cells. In the present work, we investigated the potential of the lipid-based Neutraplex nanosystem to deliver anti-HIV therapeutics in human macrophages using the human monocyte/macrophage cell line THP-1. Neutraplex nanoparticles as well as cationic and anionic Neutraplex nanolipoplexes (Neutraplex/small interfering RNA) were prepared and characterized by dynamic light scattering. Neutraplex nanoparticles showed low cytotoxicity in CellTiter-Blue reduction and lactate dehydrogenase release...
Particle and fibre toxicology, 2017
The wide application of engineered nanoparticles has induced increasing exposure to humans and environment, which led to substantial concerns on their biosafety. Some metal oxides (MOx) have shown severe toxicity in cells and animals, thus safe designs of MOx with reduced hazard potential are desired. Currently, there is a lack of a simple yet effective safe design approach for the toxic MOx. In this study, we determined the key physicochemical properties of MOx that lead to cytotoxicity and explored a safe design approach for toxic MOx by modifying their hazard properties. THP-1 and BEAS-2B cells were exposed to 0-200 μg/mL MOx for 24 h, we found some toxic MOx including CoO, CuO, Ni2O3 and Co3O4, could induce reactive oxygen species (ROS) generation and cell death due to the toxic ion shedding and/or oxidative stress generation from the active surface of MOx internalized into lysosomes. We thus hypothesized that surface passivation could reduce or eliminate the toxicity of MOx. We...
Wiley interdisciplinary reviews. Nanomedicine and nanobiotechnology, 2017
Traditionally, vaccines have been composed of live attenuated or killed microorganisms. Alternatively, individual protein subunits or other molecular components of the microorganism can serve as the antigen and trigger an antibody response by the immune system. The immune system is a coordinated molecular and cellular response that works in concert to check the spread of infection. In the past decade, there has been much progress on DNA vaccines. DNA vaccination includes using the coding segments of a viral or bacterial genome to generate an immune response. However, the potential advantage of combining an RNA molecule with inorganic nanoparticle delivery should be considered, with the goal to achieve immuno-synergy between the two and to overcome some of the current limitations of DNA vaccines and traditional vaccines. WIREs Nanomed Nanobiotechnol 2017, 9:e1415. doi: 10.1002/wnan.1415 For further resources related to this article, please visit the WIREs website.
Cobalt Compounds and Applications [Working Title], 2019
The magnetic nanoparticles (NPs) are offering a wide range of applications in medical and engineering fields. Among all the magnetic nanoparticles, cobalt oxide (Co 3 O 4) nanoparticles and its composite-based nanoparticles are attracting more interest from researchers because of its unique mechanical, thermal, and magnetic properties. The aim of this book is to bring together a number of recent contributions regarding the cobalt oxide-based composite nanoparticles from several researchers all over the world. The latest research results, innovations, and methodologies are reported in the book in order to support the discussion and to circulate ideas and knowledge about the applications of these materials in medical and engineering applications. This chapter presents the methodology for the synthesis and characterization and applications of cobalt oxide-based composite nanoparticles. The detailed analysis related to toxicity of these nanocomposite materials is also included in this book chapter.
Chemosensors
An electrochemical method was developed to investigate the redox properties of zinc oxide (ZnO), zinc peroxide (ZnO2), and sodium-doped zinc peroxide (Na-ZnO2) nanoparticles. The intention was to distinguish the identity of these nanoparticles among themselves, and from other transition metal oxide nanoparticles (TMONPs). Analysis of 3 mM sodium metabisulfite by cyclic voltammetry (CV) produced anodic/cathodic peak currents that are linearly related to the mass of deposited nanoparticles. A graphite working electrode was essential to the oxidation of metabisulfite. ZnO nanoparticles were crucial to the enhancement of metabisulfite oxidation current, and PPy coating could suppress the current enhancement by covering all nanoparticle surfaces. Furthermore, meso-tetrakis(4-carboxyphenyl) porphyrin was demonstrated to be a good chemical reagent that facilitates the differentiation of ZnO from ZnO2 and nanoparticles by CV analysis.
Nanotoxicology of Metal Oxide Nanoparticles
Metals, 2015
This review discusses recent advances in the synthesis, characterization and toxicity of metal oxide nanoparticles obtained mainly through biogenic (green) processes. The in vitro and in vivo toxicities of these oxides are discussed including a consideration of the factors important for safe use of these nanomaterials. The toxicities of different metal oxide nanoparticles are compared. The importance of biogenic synthesized metal oxide nanoparticles has been increasing in recent years; however, more studies aimed at better characterizing the potent toxicity of these nanoparticles are still necessary for nanosafely considerations and environmental perspectives. In this context, this review aims to inspire new research in the design of green approaches to obtain metal oxide nanoparticles for biomedical and technological applications and to highlight the critical need to fully investigate the nanotoxicity of these particles.