Nanotoxicity

As exciting as the futuristic applications may sound, is it possible that such technological growth may be associated with dire societal consequences In Eric E rexler s 

As we will see later in this chapter, not only is one able to alter a nanostructure by the types of atoms and their stoichiometries, but also their 3-D arrangement. With such profound nanostmctural variety, it is no wonder that standardized toxicokinetics studies i.e., absorption, distribution, metabolism, and excretion characteristics) are still greatly lacking. For this to occur, there is a need for reference nanomaterials that would allow a systematic structure V5. toxicity assessment for various classes of nanostructures. To date, the only commercially-available reference materials are spherical nanoparticles that are used to calibrate particle-size analyzers. Such reference materials will only be possible once we have standardized protocols for the synthesis and characterization of various types of nanomaterials, an active area of investigati(Mi at the National Institute of Standards and Technology (NIST). 

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The first news report on the potential damaging effects of nanoscale materials surfaced about a decade ago, when TiO JTnO nanoparticles from sunscreen were found to cause free radicals in skin cells, damaging DNA. Since then, there have been an increasing number of such reports suggesting that nanostructures are able to traverse across membranes in the body, with an increasing toxicity with decreasing nanoparticulate dimensions. Perhaps the most widely reported study surfaced in mid-2004, where it was shown that fuUerenes, a nanoscale aUotrope of carbon, cause brain damage in aquatic species. 

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Toxicity From very low to high, dependent on dye Little known yet (heavy metal leakage to be prevented, nanotoxicity)... 

Toxicity of nanoparticles is a much more complicated issue as compared with organic fluorophores Nanoparticles may be nanotoxic, they may contain cytotoxic elements or compounds, or their surface ligands/coating may contain toxic species. Nanotoxicity refers to the ability of a substance to be intrinsically cytotoxic due to its size (and independent of its constituent materials). The most prominent example of nanotoxicity is asbestos. Even though there are no systematic studies on the nanotoxicity of different nanocrystals available the results from several cytotoxicity studies suggest that nanotoxicity is not dominating for nanoparticular reporters [85, 86]. 

The fast, sensitive, reliable, and reproducible detection of (bio)molecules including quantification as well as biomolecule localization, the measurement of their interplay with one another or with other species, and the assessment of biomolecule function in bioassays as well as in vitro and in vivo plays an ever increasing role in the life sciences. The vast majority of applications exploit extrinsic fluorophores like organic dyes, fluorescent proteins, and also increasingly QDs, as the number of bright intrinsic fluorophores emitting in the visible and NIR is limited. In the near future, the use of fluorophore-doped nanoparticles is also expected to constantly increase, with their applicability in vivo being closely linked to the intensively discussed issue of size-related nanotoxicity [88]. 

NSF CREST Interdisciplinary Nanotoxicity Center, Department of Chemistry and Biochemistry, Jackson State University, Jackson, MS 39217, USA... 

NSF CREST Interdisciplinary Nanotoxicity Center, Department of Chemistry and Biochemistry, Jackson State University, 1325 Lynch, St Jackson MS 39217-0510, USA 2Laboratory of Environmental Chemometrics, Faculty of Chemistry, University of Gdansk Sobieskiego 18, 80-952 Gdansk, Poland department of Civil and Environmental Engineering, Jackson State University, 172 1325 Lynch St, Jackson, MS 39217-0510, USA e-mail jerzy icnanotox.org, danuta icnanotox.org... 

Acknowledgments The authors thank for support from the NSF CREST Interdisciplinary Nanotoxicity Center (grant number HRD-0833178). 

Acknowledgment The authors are thankful for the financial assistance and support from the NSF CREST Interdisciplinary Nanotoxicity Center (grant no. HRD-0833178), NIH-RCMI grant no. G1 2RR13459, ONR grant no. N00034-03-1-0116, and NSF-EPSCoR grant no. 300423-190200-21000. 

Designing Safer Chemicals Chemical products should be designed to effect their desired function while minimizing their toxicity. (Nanotoxicity and nanoparticle lifecycle in the environment needs to be elosely studied.)... 

For nanometer-sized particles, both size and shape may have an impact on toxicity. For many materials TEM can be used to determine the size, shape, and distribution of sizes of primary nanoparticles. However, the high vacuum environment of the TEM is drastically different than most biologically relevant environments. For this reason, studies targeting potential size-specific nanotoxicity often need to characterize materials in vitro in media that approximate those in vivo. In one such study, Murdock and cowoikers use a eombination of TEM and DLS to assess the relevance of TEM measured size when nanoparticles are dispersed in aqueous fluids (127). Some data from this work arc summarized in the table below. 

Pisanic II TR, Blackwell JD, Shubayev VI, Finones RR, Jin S. Nanotoxicity of iron oxide nanoparticle internalization in growing neurons. Biomaterials 2007 28 2572-81. 

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