Comparative Toxicity of C<sub>60</sub> Aggregates toward Mammalian Cells: Role of Tetrahydrofuran (THF) Decomposition

Kovochich, Michael; Espinasse, Benjamin; Auffan, Mélanie; Hotze, Ernest M.; Wessel, Lauren E.; Xia, Tian; Nel, André E.; Wiesner, Mark R.

doi:10.1021/es900990d

Cited by 62 publications

(43 citation statements)

References 30 publications

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“…Toxicological properties of metallic NPs are difficult to evaluate because toxicity is dependant on both the nanoparticulate form and the toxic metal ions which can be released by the NPs [4,5]. In addition, it has been found that the organic compounds used in NPs' synthesis can induce by themselves toxic effects [6]. For these reasons, it has been emphasized that NPs' toxicity is complex and many toxicological aspects still remain to be further investigated [7].…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Copper Oxide Nanoparticles Toxicity Using Chlorophyll a Fluorescence Imaging in Lemna gibba

et al. 2010

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Copper oxide nanoparticles (CuO NPs), used in antifouling paints of boats, are released in the environment and can induce toxicity to aquatic organisms. In this report, we used chlorophyll a fluorescence imaging to evaluate CuO NPs toxicity in Lemna gibba. This approach allowed to evaluate the differential effect of CuO NPs on photosynthesis of whole L. gibba plants. Exposure to 0.1 to 0.4 g/L CuO NPs during 48h induced strong inhibition of photosynthetic processes resulting in a decrease of plant growth. By using fluorescence imaging, different photosynthetic parameters were evaluated simultaneously in microplate conditions. Imaging of F O fluorescence yield showed the decrease of leaf photosynthetic active surface for whole plants exposed to CuO NPs. This method showed that CuO NPs inhibited photosystem II maximal, photosystem II operational quantum yields, and photochemical quenching of fluorescence associated with electron transport. Nonphotochemical fluorescence quenching as an indicator of energy dissipation not used in photosynthesis was shown to be increased by the effect of CuO NPs. Such approach in microplate conditions provides synchronous high repetition measurements for numerous plants. This study may give a reliable methodological approach to evaluate toxicity risk of NPs in aquatic ecosystems.

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Section: Introductionmentioning

confidence: 99%

Evaluation of Copper Oxide Nanoparticles Toxicity Using Chlorophyll a Fluorescence Imaging in Lemna gibba

et al. 2010

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“…At least four factors confound assessments of toxicity. First, it is now recognized that tetrahydrofuran (THF) used in nC 60 preparation generates toxic derivatives (13,22,29). Unless these derivatives and trace THF are removed, observed toxicity cannot be ascribed to nC 60 alone.…”

mentioning

confidence: 99%

Does Aqueous Fullerene Inhibit the Growth of Saccharomyces cerevisiae or Escherichia coli ?

Hadduck

Hindagolla

Contreras

et al. 2010

Appl Environ Microbiol

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Studies reporting on potentially toxic interactions between aqueous fullerene nanoparticles (nC 60 ) and microorganisms have been contradictory. When known confounding factors were avoided, growth yields of Saccharomyces cerevisiae and Escherichia coli cultured in the presence and absence of independently prepared lots of underivatized nC 60 were found not to be significantly different.The increasing use of nanomaterials in industrial processes and commercial products is expected to lead to accumulation of these materials in the environment. Because the consequences of increased environmental exposure are unclear, it is important that studies be undertaken to determine potential risks (4). Both deleterious effects (5,21,26,27,30) and a lack of toxicity (7, 14, 18) have been reported for aqueous nanoparticles of underivatized aqueous fullerene nanoparticles (nC 60 ). Only some of these conflicting observations have been rationalized (9). Accurately assessing doses of nanoparticles in cell culture systems can be problematic (24). The variety of methods used to prepare nC 60 also complicates interpretations of otherwise similar toxicological evaluations, because different preparation methods produce nC 60 particles with different physicochemical properties (2, 16).With specific reference to microorganisms, conflicting data have also been previously reported (19). At least four factors confound assessments of toxicity. First, it is now recognized that tetrahydrofuran (THF) used in nC 60 preparation generates toxic derivatives (13,22,29). Unless these derivatives and trace THF are removed, observed toxicity cannot be ascribed to nC 60 alone. Reports from studies that found antibacterial activity by the use of THF-solubilized nC 60 prior to this discovery are thus difficult to interpret (6,(15)(16)(17). Second, in aqueous media, hydrophobic nC 60 particles tend to agglomerate as a function of the solution condition. For some microbiological media, this leads to precipitation of nC 60 (17) and hence a reduction in the actual exposure dose. Binding of organic components in complex media to nC 60 particles can reduce nC 60 bioavailability or lead to agglomeration (15). Both effects would result in false-negative assessments of potential growth inhibition (3). Third, negative results reported from studies where C 60 powder was used directly without prior solubilization may reflect a lack of bioavailability (8,20,23,25). Fourth, potential inhibitory effects toward one or few species in mixed cultures could be masked by other species when growth is assessed at the community level (8,20,25).In light of these complications and a lack of studies done with fungi, which comprise a significant component of the soil microbial community, the toxicity of nC 60 towards the yeast Saccharomyces cerevisiae and Escherichia coli was assessed based on a simple growth endpoint under conditions where the aforementioned confounding factors were avoided. Pure microbial cultures were grown in minimal media to which carefully washed and characte...

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“…Reports that fullerenes exhibited toxicity toward various fi sh [320,321] have been discounted by other authors [322] and attributed to the presence of a tetrahydrofuran bioproduct introduced during fullerene preparation [323] .…”

Section: Nanotoxicologymentioning

confidence: 99%

Can nanotechnology potentiate photodynamic therapy?

Huang¹,

Sharma

Dai³

et al. 2012

Nanotechnology Reviews

122

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Photodynamic therapy (PDT) uses the combination of nontoxic dyes and harmless visible light to produce reactive oxygen species that can kill cancer cells and infectious microorganisms. Due to the tendency of most photosensitizers (PS) to be poorly soluble and to form nonphotoactive aggregates, drug-delivery vehicles have become of high importance. The nanotechnology revolution has provided many examples of nanoscale drug-delivery platforms that have been applied to PDT. These include liposomes, lipoplexes, nanoemulsions, micelles, polymer nanoparticles (degradable and nondegradable), and silica nanoparticles. In some cases (fullerenes and quantum dots), the actual nanoparticle itself is the PS. Targeting ligands such as antibodies and peptides can be used to increase specifi city. Gold and silver nanoparticles can provide plasmonic enhancement of PDT. Two-photon excitation or optical upconversion can be used instead of one-photon excitation to increase tissue penetration at longer wavelengths. Finally, after sections on in vivo studies and nanotoxicology, we attempt to answer the title question, " can nanotechnology potentiate PDT ? "

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Comparative Toxicity of C₆₀ Aggregates toward Mammalian Cells: Role of Tetrahydrofuran (THF) Decomposition

Cited by 62 publications

References 30 publications

Evaluation of Copper Oxide Nanoparticles Toxicity Using Chlorophyll a Fluorescence Imaging in Lemna gibba

Evaluation of Copper Oxide Nanoparticles Toxicity Using Chlorophyll a Fluorescence Imaging in Lemna gibba

Does Aqueous Fullerene Inhibit the Growth of Saccharomyces cerevisiae or Escherichia coli ?

Can nanotechnology potentiate photodynamic therapy?

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Comparative Toxicity of C60 Aggregates toward Mammalian Cells: Role of Tetrahydrofuran (THF) Decomposition

Cited by 62 publications

References 30 publications

Evaluation of Copper Oxide Nanoparticles Toxicity Using Chlorophyll a Fluorescence Imaging in Lemna gibba

Evaluation of Copper Oxide Nanoparticles Toxicity Using Chlorophyll a Fluorescence Imaging in Lemna gibba

Does Aqueous Fullerene Inhibit the Growth of Saccharomyces cerevisiae or Escherichia coli ?

Can nanotechnology potentiate photodynamic therapy?

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Comparative Toxicity of C₆₀ Aggregates toward Mammalian Cells: Role of Tetrahydrofuran (THF) Decomposition