Semiconductor quantum dots and free radical induced DNA nicking

Green, Mark; Howman, Emily V.

doi:10.1039/b413175d

Cited by 286 publications

(179 citation statements)

References 15 publications

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“…Addition of QDs to DNA solutions is known to lead to DNA damage upon irradiation with light of λ > 310 nm, a spectral region where DNA itself does not absorb, 28 or, in the dark, via ROS mediated chemical reactions. 29 Hoshino et al were…”

Section: Nanogenomic Effects Of Qdsmentioning

confidence: 99%

Quantum Dot Cytotoxicity and Ways To Reduce It

2012

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T he dramatic increase in the use of nanoparticles (NP) in industry and research has raised questions about the potential toxicity of such materials. Unfortunately, not enough is known about how the novel, technologically-attractive properties of NPs correlate with the interactions that may take place at the nano/bio interface. The academic, industrial, and regulatory communities are actively seeking answers to the growing concerns on the impact of nanotechnology on humans. In this Account we adopt quantum dots (QDs) as an illustrative example of the difficulties associated with the development of a rational sciencebased approach to nanotoxicology.The optical properties of QDs are far superior to those of organic dyes in terms of emission and absorption bandwidths, quantum yield, and resistance to photobleaching. Moreover, QDs may be decorated with targeting moieties or drugs and, therefore, are candidates for site-specific medical imaging and for drug delivery, for example in cancer treatment. Earlier this year researchers demonstrated that QD-based imaging using monkeys caused no adverse effects although QDs accumulated in lymph nodes, bone marrow, liver, and spleen for up to 3 months after injection. Such persistence of QDs in live animals does, however, raise concerns about the safety of using QDs both in the laboratory and in the clinic.Researchers anticipate that QDs will be increasingly used not only in clinical applications but also in various manufactured products. For example, QD-solar cells have emerged as viable contenders to complement or replace dye-sensitized solar cells; CdTe/CdS thin film cells have already captured approximately 10 percent of the global market, and in addition, QDs can serve as components of sensors and as emitting materials in LEDs. Given the clear indications that QDs will inevitably become components of a wide range of manufactured and consumer products, researchers and policy makers need to understand the possible health risks associated with exposure to QDs.In this Account, we initially review the known mechanisms by which QDs can damage cells, including oxidative stress elicited by reactive oxygen species (ROS). We discuss lesser-known impairments induced in cells by nanomolar to picomolar concentrations of QDs, which imply that cadmium-containing QDs can exert genotoxic, epigenetic, and metalloestrogenic effects. These observations strongly suggest that minute concentrations of QDs could be sufficient to cause long lasting, even transgenerational, effects. We also consider various modes by which humans could be exposed to QDs in their work or through the environment. Although considerable advances have been made in enhancing the stability and overall quality of QDs, over time they can partially degrade in the environment or in biological systems, and eventually cause small, but cumulative undesirable effects.A combination of toxicological, genetic, epigenetic and imaging approaches is required to create comprehensive guidelines for evaluating the nanotoxicity of nanomate...

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Section: Nanogenomic Effects Of Qdsmentioning

confidence: 99%

Quantum Dot Cytotoxicity and Ways To Reduce It

2012

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“…The lysine residues on the external surface of lactoferrin can be used to covalently couple molecules [19][20][21][22] [24][25][26].…”

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confidence: 99%

Monitoring lactoferrin iron levels by fluorescence resonance energy transfer: a combined chemical and computational study

et al. 2014

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Abstract.Three forms of lactoferrin (Lf) that differed in their levels of iron loading (Lf, LfFe, and LfFe 2 ) were simultaneously labeled with the fluorophores AF350 and AF430. All three resulting fluorescent lactoferrins exhibited fluorescence resonance energy transfer (FRET), but they all presented different FRET patterns. Whereas only partial FRET was observed for Lf and LfFe, practically complete FRET was seen for the holo form (LfFe 2 ). For each form of metal-loaded lactoferrin, the AF350-AF430 distance varied depending on the protein conformation, which in turn depended on the level of iron loading. Thus, the FRET patterns of these lactoferrins were found to correlate with their iron loading levels. In order to gain greater insight into the number of fluorophores and the different FRET patterns observed (i.e., their iron levels), a computational analysis was performed. The results highlighted a number of lysines that have the greatest influence on the FRET profile. Moreover, despite the lack of an X-ray structure for any LfFe species, our study also showed that this species presents modified subdomain organization of the N-lobe, which narrows its iron-binding site. Complete domain rearrangement occurs during the LfFe to LfFe 2 transition. This latter study demonstrated that lactoferrin supplies iron to this bacterium, and suggested that this process occurs with no protein internalization.

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“…Because little is known about the toxicity profile of nanomaterials, no benchmarks or ''safe'' levels have been set for the concern of human health. Presently, more and more researchers have investigated the toxicological effects and potential environmental impacts of nanomaterials, such as single-walled carbon nanotubes (Cui et al, 2005;Warheit et al, 2004), multi-walled carbon nanotubes (Monteiro-Riviere et al, 2005), fullerenes (Chen et al, 1998;Oberdö rster, 2004;Sayes et al, 2005), ultrafine titanium dioxide (Nakagawa et al, 1997;Rahman et al, 2002), quantum dots (Derfus et al, 2004;Green and Howman, 2005), and some transition metals like Cu, Au, Ag, Zn, and their oxides (Goodman et al, 2004;Chen et al, 2006). However, limited available toxicological information on nanomaterials renders people to endure a high risk of using these novel materials, especially in biological and medical applications.…”

Section: Introductionmentioning

confidence: 99%

Effects of waterborne nano-iron on medaka (Oryzias latipes): Antioxidant enzymatic activity, lipid peroxidation and histopathology

Zhou

et al. 2009

Ecotoxicology and Environmental Safety

186

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a b s t r a c tToxicity tests were performed to investigate possible harmful effects on medaka exposed to nano-iron. Dose-dependent decreases of superoxide dismutase (SOD) and increases of malondialdehyde (MDA) were induced in the medaka embryo, suggesting that oxidative damage was induced by nano-iron. For adult medaka, the disturbance of antioxidative balance was observed during the early exposure period based on the monitoring of the hepatic and cerebral SOD and reduced glutathione (GSH). No terminal oxidative damage occurred during the whole exposure period, probably due to the high self-recovering capability of the adult fish. Some histopathological and morphological alterations (cell swelling, hyperplasia, and granulomas, etc.) were observed in gill and intestine tissues, which confirmed that deleterious effects occurred as a result of direct contact with nano-iron. It is suggested that further evaluation should be made concerning the risk assessment of waterborne nano-iron on aquatic life.

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Semiconductor quantum dots and free radical induced DNA nicking

Cited by 286 publications

References 15 publications

Quantum Dot Cytotoxicity and Ways To Reduce It

Quantum Dot Cytotoxicity and Ways To Reduce It

Monitoring lactoferrin iron levels by fluorescence resonance energy transfer: a combined chemical and computational study

Effects of waterborne nano-iron on medaka (Oryzias latipes): Antioxidant enzymatic activity, lipid peroxidation and histopathology

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