Biomedical Engineering Reference
In-Depth Information
8
Analytical Characterization
of Nanomaterials in Biological
Matrices for Hazard
Assessment
Mingsheng Xu, Daisuke Fujita, Huanxing Su, Hongzheng
Chen, and Nobutaka Hanagata
CONTENTS
8.1 Introduction .......................................................................................................................... 159
8.2 Characterization of Primary NMs in Dry State ................................................................... 160
8.2.1 Terminology and Definitions for NMs ..................................................................... 160
8.2.2 Physicochemical Characterization of Primary NMs ................................................ 163
8.2.3 Characterization in Biological Matrices ................................................................... 166
8.2.4 Characterization of NMs in Biological Matrices by Electron Microscopy .............. 166
8.2.5 Characterization of NMs in Biological Matrices by Raman Spectroscopy ............. 167
8.2.6 Characterization of Dissolution of NMs in a Biological Matrix .............................. 168
8.3 Conclusion ............................................................................................................................ 170
Acknowledgments .......................................................................................................................... 170
References ...................................................................................................................................... 171
8.1 INTRODUCTION
Novel nanomaterials (NMs) are playing key roles in nanotechnology innovations. As a consequence
of their small size, NMs exhibit unique physicochemical properties and biological effects as com-
pared to their respective bulk materials. NMs are increasingly used in a wide variety of industrial
processes and consumer products. Although the obvious beneficial effects of NMs are well recog-
nized, the increased presence of NMs raises concerns about the adverse effects on the environment,
health, and society (so-called NanoEHS). There is growing evidence to suggest that complicated
interaction processes may occur between NMs and biological systems [1,2] and to show that NMs,
including carbon nanotubes, fullerenes, quantum dots such as CdS, oxide nanoparticles (NPs) such
as ZnO, and CuO and TiO
2
, exhibit various toxic effects on biological systems [3-6].
In spite of numerous publications on the investigations of the potential impacts of NMs, the
progress is very slow. There are, at present, no standard methods for nanotoxicology, which might
possibly lead to opposing results for the same NM. For example, in general, the concerns about
the toxicity of NMs have been primarily based on the assumption that small-sized NMs are more
toxic than large ones, and there are many reports showing that toxicity increases with a decrease
in the particle size of NMs [7]. However, there are also findings that the cytotoxicity of NPs, such
as SiO
2
, is not a function of their primary size [3]. Many studies have attributed the toxic effects
of metal-based NPs, such as ZnO, primarily to released metal cations [9], but other studies showed
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