scholarly journals Molecular Mechanisms of Zinc Oxide Nanoparticle-Induced Genotoxicity

Materials ◽  
2017 ◽  
Vol 10 (12) ◽  
pp. 1427 ◽  
Author(s):  
Agmal Scherzad ◽  
Till Meyer ◽  
Norbert Kleinsasser ◽  
Stephan Hackenberg

Background: Zinc oxide nanoparticles (ZnO NPs) are among the most frequently applied nanomaterials in consumer products. Evidence exists regarding the cytotoxic effects of ZnO NPs in mammalian cells; however, knowledge about the potential genotoxicity of ZnO NPs is rare, and results presented in the current literature are inconsistent. Objectives: The aim of this review is to summarize the existing data regarding the DNA damage that ZnO NPs induce, and focus on the possible molecular mechanisms underlying genotoxic events. Methods: Electronic literature databases were systematically searched for studies that report on the genotoxicity of ZnO NPs. Results: Several methods and different endpoints demonstrate the genotoxic potential of ZnO NPs. Most publications describe in vitro assessments of the oxidative DNA damage triggered by dissoluted Zn2+ ions. Most genotoxicological investigations of ZnO NPs address acute exposure situations. Conclusion: Existing evidence indicates that ZnO NPs possibly have the potential to damage DNA. However, there is a lack of long-term exposure experiments that clarify the intracellular bioaccumulation of ZnO NPs and the possible mechanisms of DNA repair and cell survival.

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4062
Author(s):  
Till Jasper Meyer ◽  
Agmal Scherzad ◽  
Helena Moratin ◽  
Thomas Eckert Gehrke ◽  
Julian Killisperger ◽  
...  

Radioresistance is an important cause of head and neck cancer therapy failure. Zinc oxide nanoparticles (ZnO-NP) mediate tumor-selective toxic effects. The aim of this study was to evaluate the potential for radiosensitization of ZnO-NP. The dose-dependent cytotoxicity of ZnO-NP20 nm and ZnO-NP100 nm was investigated in FaDu and primary fibroblasts (FB) by an MTT assay. The clonogenic survival assay was used to evaluate the effects of ZnO-NP alone and in combination with irradiation on FB and FaDu. A formamidopyrimidine-DNA glycosylase (FPG)-modified single-cell microgel electrophoresis (comet) assay was applied to detect oxidative DNA damage in FB as a function of ZnO-NP and irradiation exposure. A significantly increased cytotoxicity after FaDu exposure to ZnO-NP20 nm or ZnO-NP100 nm was observed in a concentration of 10 µg/mL or 1 µg/mL respectively in 30 µg/mL of ZnO-NP20 nm or 20 µg/mL of ZnO-NP100 nm in FB. The addition of 1, 5, or 10 µg/mL ZnO-NP20 nm or ZnO-NP100 nm significantly reduced the clonogenic survival of FaDu after irradiation. The sub-cytotoxic dosage of ZnO-NP100 nm increased the oxidative DNA damage compared to the irradiated control. This effect was not significant for ZnO-NP20 nm. ZnO-NP showed radiosensitizing properties in the sub-cytotoxic dosage. At least for the ZnO-NP100 nm, an increased level of oxidative stress is a possible mechanism of the radiosensitizing effect.


Blood ◽  
1998 ◽  
Vol 92 (2) ◽  
pp. 632-638 ◽  
Author(s):  
Louise Cragg ◽  
Robert P. Hebbel ◽  
Wesley Miller ◽  
Alex Solovey ◽  
Scott Selby ◽  
...  

Abstract Iron-mediated carcinogenesis is thought to occur through the generation of oxygen radicals. Iron chelators are used in attempts to prevent the long term consequences of iron overload. In particular, 1,2-dimethyl-3-hydroxypyrid-4-one (L1), has shown promise as an effective chelator. Using an established hepatocellular model of iron overload, we studied the generation of iron-catalyzed oxidative DNA damage and the influence of iron chelators, including L1, on such damage. Iron loading of HepG2 cells was found to greatly exacerbate hydrogen peroxide–mediated DNA damage. Desferrithiocin was protective against iron/hydrogen peroxide–induced DNA damage; deferoxamine had no effect. In contrast, L1 exposure markedly potentiated hydrogen peroxide–mediated oxidative DNA damage in iron-loaded liver cells. However, when exposure to L1 was maintained during incubation with hydrogen peroxide, L1 exerted a protective effect. We interpret this as indicating that L1's potential toxicity is highly dependent on the L1:iron ratio. In vitro studies examining iron-mediated ascorbate oxidation in the presence of L1 showed that an L1:iron ratio must be at least 3 to 1 for L1 to inhibit the generation of free radicals; at lower concentrations of L1 increased oxygen radical generation occurs. In the clinical setting, such potentiation of iron-catalyzed oxidative DNA damage at low L1:iron ratios may lead to long-term toxicities that might preclude administration of L1 as an iron chelator. Whether this implication in fact extends to the in vivo situation will have to be verified in animal studies.


Cells ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 1081
Author(s):  
Ana Rita Pinho ◽  
Filipa Martins ◽  
M. Elisabete V. Costa ◽  
Ana M. R. Senos ◽  
Odete A. B. da Cruz e Silva ◽  
...  

Zinc Oxide Nanoparticles (ZnO NPs) are a type of metal oxide nanoparticle with an extensive use in biomedicine. Several studies have focused on the biosafety of ZnO NPs, since their size and surface area favor entrance and accumulation in the body, which can induce toxic effects. In previous studies, ZnO NPs have been identified as a dose- and time-dependent cytotoxic inducer in testis and male germ cells. However, the consequences for the first cell stage of spermatogenesis, spermatogonia, have never been evaluated. Therefore, the aim of the present work is to evaluate in vitro the cytotoxic effects of ZnO NPs in spermatogonia cells, focusing on changes in cytoskeleton and nucleoskeleton. For that purpose, GC-1 cell line derived from mouse testes was selected as a model of spermatogenesis. These cells were treated with different doses of ZnO NPs for 6 h and 12 h. The impact of GC-1 cells exposure to ZnO NPs on cell viability, cell damage, and cytoskeleton and nucleoskeleton dynamics was assessed. Our results clearly indicate that higher concentrations of ZnO NPs have a cytotoxic effect in GC-1 cells, leading to an increase of intracellular Reactive Oxygen Species (ROS) levels, DNA damage, cytoskeleton and nucleoskeleton dynamics alterations, and consequently cell death. In conclusion, it is here reported for the first time that ZnO NPs induce cytotoxic effects, including changes in cytoskeleton and nucleoskeleton in mouse spermatogonia cells, which may compromise the progression of spermatogenesis in a time- and dose-dependent manner.


Blood ◽  
1998 ◽  
Vol 92 (2) ◽  
pp. 632-638 ◽  
Author(s):  
Louise Cragg ◽  
Robert P. Hebbel ◽  
Wesley Miller ◽  
Alex Solovey ◽  
Scott Selby ◽  
...  

Iron-mediated carcinogenesis is thought to occur through the generation of oxygen radicals. Iron chelators are used in attempts to prevent the long term consequences of iron overload. In particular, 1,2-dimethyl-3-hydroxypyrid-4-one (L1), has shown promise as an effective chelator. Using an established hepatocellular model of iron overload, we studied the generation of iron-catalyzed oxidative DNA damage and the influence of iron chelators, including L1, on such damage. Iron loading of HepG2 cells was found to greatly exacerbate hydrogen peroxide–mediated DNA damage. Desferrithiocin was protective against iron/hydrogen peroxide–induced DNA damage; deferoxamine had no effect. In contrast, L1 exposure markedly potentiated hydrogen peroxide–mediated oxidative DNA damage in iron-loaded liver cells. However, when exposure to L1 was maintained during incubation with hydrogen peroxide, L1 exerted a protective effect. We interpret this as indicating that L1's potential toxicity is highly dependent on the L1:iron ratio. In vitro studies examining iron-mediated ascorbate oxidation in the presence of L1 showed that an L1:iron ratio must be at least 3 to 1 for L1 to inhibit the generation of free radicals; at lower concentrations of L1 increased oxygen radical generation occurs. In the clinical setting, such potentiation of iron-catalyzed oxidative DNA damage at low L1:iron ratios may lead to long-term toxicities that might preclude administration of L1 as an iron chelator. Whether this implication in fact extends to the in vivo situation will have to be verified in animal studies.


2020 ◽  
Vol 39 (4) ◽  
pp. 321-327 ◽  
Author(s):  
Søren T. Larsen ◽  
Emilie Da Silva ◽  
Jitka S. Hansen ◽  
Alexander C. Ø. Jensen ◽  
Ismo K. Koponen ◽  
...  

People can be exposed to zinc oxide (ZnO) by inhalation of consumer products or during industrial processes. Zinc oxide nanoparticle (NP) exposure can induce acute inhalation toxicity. The toxicological mechanisms underlying the acute effects on the lungs have long focused on the phagolysosomal dissolution of ZnO NPs in macrophages followed by the release of free Zn2+ ions. However, we postulate an alternative mechanism based on the direct interaction of ZnO NPs with the lung surfactant (LS) layer covering the inside of the alveoli. Therefore, we tested the effect of ZnO NPs and Zn2+ ions on the function of LS in vitro using the constrained drop surfactometer. We found that the ZnO NPs inhibited the LS function, whereas Zn2+ ions did not. To examine the role of lung macrophages in the acute toxicity of inhaled ZnO NPs, mice were treated with Clodrosome, a drug that depletes alveolar macrophages, or Encapsome, the empty carrier of the drug. After macrophage depletion, the mice were exposed to an aerosol of ZnO NPs in whole body plethysmographs recording breathing patterns continuously. Mice in both groups developed shallow breathing (reduced tidal volume) shortly after the onset of exposure to ZnO NPs. This suggests a macrophage-independent mechanism of induction. This study shows that acute inhalation toxicity is caused by ZnO NP interaction with LS, independently of NP dissolution in macrophages.


Biomolecules ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1442
Author(s):  
Josefa Domenech ◽  
Mariana de Britto ◽  
Antonia Velázquez ◽  
Susana Pastor ◽  
Alba Hernández ◽  
...  

The increasing presence of micro- and nanoplastics (MNPLs) in the environment, and their consequent accumulation in trophic niches, could pose a potential health threat to humans, especially due to their chronic ingestion. In vitro studies using human cells are considered pertinent approaches to determine potential health risks to humans. Nevertheless, most of such studies have been conducted using short exposure times and high concentrations. Since human exposure to MNPLs is supposed to be chronic, there is a lack of information regarding the potential in vitro MNPLs effects under chronic exposure conditions. To this aim, we assessed the accumulation and potential outcomes of polystyrene nanoparticles (PSNPs), as a model of MNPLs, in undifferentiated Caco-2 cells (as models of cell target in ingestion exposures) under a relevant long-term exposure scenario, consisting of eight weeks of exposure to sub-toxic PSNPs concentrations. In such exposure conditions, culture-media was changed every 2–3 days to maintain constant exposure. The different analyzed endpoints were cytotoxicity, dysregulation of stress-related genes, genotoxicity, oxidative DNA damage, and intracellular ROS levels. These are endpoints that showed to be sensitive enough in different studies. The obtained results attest that PSNPs accumulate in the cells through time, inducing changes at the ultrastructural and molecular levels. Nevertheless, minor changes in the different evaluated genotoxicity-related biomarkers were observed. This would indicate that no DNA damage or oxidative stress is observed in the human intestinal Caco-2 cells after long-term exposure to PSNPs. This is the first study dealing with the long-term effects of PSNPs on human cultured cells.


2021 ◽  
Vol 95 ◽  
Author(s):  
T. Shafienejad Jalali ◽  
F. Malekifard ◽  
B. Esmaeilnejad ◽  
S. Asri Rezaie

Abstract This study investigated the in vitro anthelmintic activity of copper oxide (CuO) and zinc oxide (ZnO) nanoparticles (NPs) against Marshallagia marshalli. The in vitro study was based on an egg hatch assay, adult and larvae motility inhibition assays, DNA damage, intensity protein profile along with several oxidative/nitrosative stress biomarkers including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), protein carbonylation (PCO), malondialdehyde (MDA), total antioxidant status (TAS) and nitric oxide (NO) content. Different concentrations of CuO-NPs and ZnO-NPs (1, 4, 8, 12 and 16 ppm) were used to assess anthelmintic effects on three stages of M. marshalli life cycle – that is, eggs, larvae and adult parasites for 24 h. The results indicated that CuO-NPs and ZnO-NPs played a significant role as anthelminthics, and the effect was dependent on time and concentration. The concentrations of 12 and 16 ppm of CuO-NPs and 16 ppm of ZnO-NPs resulted in the induction of oxidative/nitrosative stress (decreased SOD, GSH-Px and CAT, and increased MDA, PCO and NO), increased DNA damage, inhibition of adult and larval motility, egg hatch and low intensity of protein bands following sodium dodecyl sulphate–polyacrylamide gel electrophoresis, compared to control. It was concluded that CuO-NPs and ZnO-NPs could be utilized as novel and potential agents for the control and treatment of M. marshalli infection, and they have the pharmacological potential to be studied in vivo for further utilization in treating parasitic infections.


Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1930
Author(s):  
Vanessa Valdiglesias ◽  
Natalia Fernández-Bertólez ◽  
Carlota Lema-Arranz ◽  
Raquel Rodríguez-Fernández ◽  
Eduardo Pásaro ◽  
...  

Metal oxide nanoparticles (NPs) have a wide variety of applications in many consumer products and biomedical practices. As a result, human exposure to these nanomaterials is highly frequent, becoming an issue of concern to public health. Recently, human salivary leucocytes have been proposed as an adequate non-invasive alternative to peripheral blood leucocytes to evaluate genotoxicity in vitro. The present study focused on proving the suitability of salivary leucocytes as a biomatrix in the comet assay for in vitro nanogenotoxicity studies, by testing some of the metal oxide NPs most frequently present in consumer products, namely, titanium dioxide (TiO2), zinc oxide (ZnO), and cerium dioxide (CeO2) NPs. Primary and oxidative DNA damage were evaluated by alkaline and hOGG1-modified comet assay, respectively. Any possible interference of the NPs with the methodological procedure or the hOGG1 activity was addressed before performing genotoxicity evaluation. Results obtained showed an increase of both primary and oxidative damage after NPs treatments. These data support the use of salivary leucocytes as a proper and sensitive biological sample for in vitro nanogenotoxicity studies, and contribute to increase the knowledge on the impact of metal oxide NPs on human health, reinforcing the need for a specific regulation of the nanomaterials use.


2021 ◽  
Vol 22 (13) ◽  
pp. 6663
Author(s):  
Maurycy Jankowski ◽  
Mariusz Kaczmarek ◽  
Grzegorz Wąsiatycz ◽  
Claudia Dompe ◽  
Paul Mozdziak ◽  
...  

Next-generation sequencing (RNAseq) analysis of gene expression changes during the long-term in vitro culture and osteogenic differentiation of ASCs remains to be important, as the analysis provides important clues toward employing stem cells as a therapeutic intervention. In this study, the cells were isolated from adipose tissue obtained during routine surgical procedures and subjected to 14-day in vitro culture and differentiation. The mRNA transcript levels were evaluated using the Illumina platform, resulting in the detection of 19,856 gene transcripts. The most differentially expressed genes (fold change >|2|, adjusted p value < 0.05), between day 1, day 14 and differentiated cell cultures were extracted and subjected to bioinformatical analysis based on the R programming language. The results of this study provide molecular insight into the processes that occur during long-term in vitro culture and osteogenic differentiation of ASCs, allowing the re-evaluation of the roles of some genes in MSC progression towards a range of lineages. The results improve the knowledge of the molecular mechanisms associated with long-term in vitro culture and differentiation of ASCs, as well as providing a point of reference for potential in vivo and clinical studies regarding these cells’ application in regenerative medicine.


Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1919
Author(s):  
Elsayim Rasha ◽  
AlOthman Monerah ◽  
Alkhulaifi Manal ◽  
Ali Rehab ◽  
Doud Mohammed ◽  
...  

Recently, concerns have been raised globally about antimicrobial resistance, the prevalence of which has increased significantly. Carbapenem-resistant Klebsiella pneumoniae (KPC) is considered one of the most common resistant bacteria, which has spread to ICUs in Saudi Arabia. This study was established to investigate the antibacterial activity of biosynthesized zinc oxide nanoparticles (ZnO-NPs) against KPC in vitro and in vivo. In this study, we used the aqueous extract of Acacia nilotica (L.) fruits to mediate the synthesis of ZnO-NPs. The nanoparticles produced were characterized by UV-vis spectroscopy, zetasizer and zeta potential analyses, X-ray diffraction (XRD) spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM). The antimicrobial activity of ZnO-NPs against KPC was determined via the well diffusion method, and determining minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), the results showed low MIC and MBC when compared with the MIC and MBC of Imipenem and Meropenem antibiotics. The results of in vitro analysis were supported by the results upon applying ZnO-NP ointment to promote wound closure of rats, which showed better wound healing than the results with imipenem ointment. The biosynthesized ZnO-NPs showed good potential for use against bacteria due to their small size, applicability, and low toxicity to human cells.


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