Biomedical Engineering Reference
In-Depth Information
14.4.3.6 Toxicity of Engineered Nanomaterials
Yokel et al. carried out an investigation to study the distribution and clearance of ceria engineered
nanomaterial (ceria ENM) in blood. The presence of ceria ENM was verified by electron microscopy.
The highest concentrations were seen in macrophages of RES tissues, as has been observed for other
insoluble ENMs (Yokel et al. 2009). These results illustrate the prolonged retention of nondegradable
ENM, consistent with reports of titanium (Fabian et al. 2008; Van et al. 2009), gold (Cho et al. 2009b),
and functionalized QDs (Ballou et al. 2004; Fischer et al. 2006; Yang et al. 2007; Lin et al. 2008).
Within cells of RES tissues, ceria ENM were often found in agglomerations (collections of particles
loosely bound by relatively weak forces, such as van der Waals, electrostatic, physical entanglement,
and surface tension). The prolonged determination of these ceria agglomerates was associated with
histopathological changes, including granulomatous formations in the spleen (William et al. 2012).
No significant decreases of the amount (mass) of cerium was seen in the liver or spleen of rats
up to 30 days after IV administration of 5 or 30 nm ceria ENM. Hepatic granulomas and giant cells
containing agglomerates in the cytoplasm of the red pulp and thickened arterioles in white pulp
were seen in the spleen (Dan et al. 2010).
14.5 SUMMARY
Nanomaterials have become an inherent part of our daily life, as they are being increasingly used
in multifaceted areas such as medicines, prosthetics, engineering materials, articles, paints, clothes,
and countless other household products. Ecotoxicological issues owing to nanomaterials have
received even less attention, which is appalling since the production of nanomaterials has grown
over the past few years.
In the last few years, research on toxicologically relevant properties of engineered nanoparticles
has increased enormously. A number of international research projects and additional activities are
ongoing in the European Union and the United States, nurturing the anticipation that more relevant
technical and toxicological data will be published. Their widespread use allows for the likelihood
of exposures for a variety of engineered nanoparticles during the whole lifecycle.
With recent developments in nanotechnology, the utilization of nanomaterials in various industrial
applications such as medicine and cosmetics has enhanced successfully. Nanomaterials demonstrate
useful properties such as electronic reactivity and tissue permeability that are absent in micromateri-
als. Hence, it is predicted that nanomaterials will develop as innovative materials in medicine and
the cosmetics industry. Nevertheless, these innovative properties may be accompanied by unknown
biological responses that could not have been detected by conventional toxicity assays.
Nanotoxicity is defined as the study of nature and mechanism of toxic effect of nanoscale materi-
als on living organism and other biological system and is intended to address the toxicological activi-
ties of nanoparticles and their products to determine whether and to what extent they may pose a
threat to the environment and to human health. It also deals with quantitative assessment of the sever-
ity and frequency of nanotoxic effects in relation to the exposure of the organism. The knowledge
from nanotoxicological studies will be the basis for designing safe nanomaterials and nanoproducts,
and also directs uses in nanomedical sciences. As various tissue and organs have different composi-
tions, structures, and functions, toxic responses are most different once nanoparticles enter an organ.
REFERENCES
Akgun, H., Gonlusen, G., Cartwright, J., Suki, W.N., and Truong, L.D. 2006. Are gadolinium-based contrast
media nephrotoxic?
Arch Pathol Lab Med
130:1354-1357.
Allen, T.M. and Hansen, C. 1991. Pharmacokinetics of stealth versus conventional liposomes: Effect of dose.
Biochim Biophys Acta
1068:133-141.
Anderson, J.T. and Sandlie, I. 2009. The versatile MHC Class 1-related FcRn protects IgG and albumin
from degradation: Implications for the development of new diagnostics and therapeutics.
Drug Metab
Pharmacokinet
24:318-332.
