Toxicological EFFECT of ZnO nanoparticles based on bacteria. Langmuir 24: 4140-4144

College of Materials Science and Engineering, Sichuan University, Chengdu, China.
Langmuir (Impact Factor: 4.46). 05/2008; 24(8):4140-4. DOI: 10.1021/la7035949
Source: PubMed


Streptococcus agalactiae and Staphylococcus aureus are two pathogenetic agents of several infective diseases in humans. Biocidal effects and cellular internalization of ZnO nanoparticles (NPs) on two bacteria are reported, and ZnO NPs have a good bacteriostasis effect. ZnO NPs were synthesized in the EG aqueous system through the hydrolysis of ionic Zn2+ salts. Particle size and shape were controlled by the addition of the various surfactants. Bactericidal tests were performed in an ordinary broth medium on solid agar plates and in liquid systems with different concentrations of ZnO NPs. The biocidal action of ZnO materials was studied by transmission electron microscopy of bacteria ultrathin sections. The results confirmed that bactericidal cells were damaged after ZnO NPs contacted with them, showing both gram-negative membrane and gram-positive membrane disorganization. The surface modification of ZnO NPs causes an increase in membrane permeability and the cellular internalization of these NPs whereas there is a ZnO NP structure change inside the cells.

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    • "Due to these wide-ranging applications, the potential effects of ZnO nanoparticles on human and environmental health have also attracted broad attention. Recent studies have shown that ZnO nanoparticles can be toxic to a wide range of biological systems, including human epidermal cells [Sharma et al., 2009], bacteria (Streptococcus agalactiae and Staphylococcus aureus) [Huang et al., 2008], zebra fish (Danio rerio) [Zhu et al., 2008], and mice [Wang et al., 2008]. Toxicity concerns for nanoparticles arise from their smaller size and higher surface-to-volume ratio compared with larger particles, as the smaller size might result in greater particle uptake by cells, and the smaller size and larger accessible surface allows for increased and possibly novel physical and/or chemical interactions with biomolecules inside cells with the potential to disrupt complex membrane and cytoskeletal systems and even DNA replication [Nel et al., 2006]. "
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    ABSTRACT: The relationship between particle size and cytogenotoxicity of ZnO particles was systematically studied in vitro using WIL2-NS human lymphoblastoid cells. Before toxicity measurements, the ZnO particles of three different sizes (26 nm, 78 nm, and 147 nm) were well characterized for their physical and chemical properties to ensure that variations in other properties including surface chemistry and particle shape, which also may influence particle toxicity, were minimal. Cell viability testing showed that increasing cytotoxicity was associated with decreasing particle size. Both the dissolution kinetics of ZnO particles in supplemented cell culture medium and the apparent numbers of ZnO particles internalized by cells were size dependent and showed strong correlation with cytotoxicity. Genotoxicity, as measured by micronucleus formation, was significantly enhanced in the presence of the medium-sized and large-sized particles. The observation that necrosis increased with smaller- sized particles but micronuclei were present to a greater extent with larger- sized particles suggests that different mechanisms of cell damage induction or susceptibilities are operating depending on particle size. Environ. Mol. Mutagen., 2015. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.
    Environmental and Molecular Mutagenesis 08/2015; DOI:10.1002/em.21962 · 2.63 Impact Factor
    • "The range of ZnO NM concentrations that are considered toxic vary across these studies and the results are species specific. Some environmental studies found no or little difference between the toxicity of micro-and nanoscale ZnO particles (Aruoja et al. 2009; Zhu et al. 2008), some found that ZnO NMs had less of a detrimental effect than zinc ions (Hooper et al. 2011), some found no effect (Mortimer et al. 2008; Adams et al. 2006) whereas others found that development, reproduction and survival were affected after exposure to ZnO NMs (Blinova et al. 2010; Heinlaan et al. 2008; Huang et al. 2008). Some of the ZnO NM studies which have used crustaceans (Blinova et al. 2010), protozoa (Blinova et al. 2010) and algae (Franklin et al. 2007; Aruoja et al. 2009) as test species, have stated that the toxicity observed in their studies was down to ions rather than NMs. "
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    ABSTRACT: These studies were undertaken in order to propose and test new methods for the assessment of the acute hazard of ZnO nanoparticles (NPs) to the sediment dwelling oligochaete worm Lumbriculus variegatus. In order to support the developing nanotechnology sector, comprehensive studies must be conducted to assess the toxicity of nanomaterials (NMs) using environmentally relevant organisms. An important part of such studies will entail characterising and understanding the physicochemical properties of these NMs. In this study NMs were characterised using a range of techniques, in order to assess agglomeration/aggregation and dissolution. Toxicology studies included a behavioural assay and the measurement of oxidative stress. When considering the toxicology results from all experiments using L. variegatus within this paper ZnO NPs (0-10 mg/l) were found to cause acute toxicity in terms of behavioural response, but not to cause acute oxidative stress in terms of glutathione (GSH) depletion. It was also concluded that the behavioural assay and the GSH assay were both suitable techniques for assessing the acute hazard of NMs to L. variegatus.
    Ecotoxicology 07/2015; 24(6). DOI:10.1007/s10646-015-1515-8 · 2.71 Impact Factor
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    • "Uptake of nano-ZnO by E. coli cells was reported in some previous studies using TEM (Brayner et al. 2006; Huang et al. 2008; Tama et al. 2008). Kumar et al. also demonstrated the uptake of nano-ZnO in S. typhimurium using flow cytometry (Kumar et al. 2011). "
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    ABSTRACT: Increasing production and applications of nano zinc oxide particles (nano-ZnO) enhances the probability of its exposure in occupational and environmental settings, but toxicity studies are still limited. Taking the free Zn ion (Zn(2+)) as a control, cytotoxicity of a commercially available nano-ZnO was assessed with a 6-h exposure in Escherichia coli (E. coli). The fitted dose-cytotoxicity curve for ZnCl2 was significantly sharper than that from nano-ZnO. Then, a genome-wide gene expression profile following exposure to nano-ZnO was conducted by use of a live cell reporter assay system with library of 1820 modified green fluorescent protein (GFP)-expressing promoter reporter vectors constructed from E. coli K12 strains, which resulted in 387 significantly altered genes in bacterial (p < 0.001). These altered genes were enriched into ten biological processing and two cell components (p < 0.05) terms through statistical hypergeometric testing, strongly suggesting that exposure to nano-ZnO would result a great disturbance on the functional gene product synthesis processing, such as translation, gene expression, RNA modification, and structural constituent of ribosome. The pattern of expression of 37 genes altered by nano-ZnO (fold change>2) was different from the profile following exposure to 6 mg/L of free zinc ion. The result indicates that these two Zn forms might cause toxicity to bacterial in different modes of action. Our results underscore the importance of understanding the adverse effects elicited by nano-ZnO after entering aquatic environment.
    Environmental Science and Pollution Research 05/2015; DOI:10.1007/s11356-015-4507-6 · 2.83 Impact Factor
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