A Review of Toxicity of Some Conventional Nanomaterials

Document Type: Original Article

Abstract

Increased production and use of nanomaterials has led to an ever growing exposure of living
organisms to these substances. Limited knowledge about possible toxicity of nanomaterials
and their potential to harm living creatures is becoming a serious concern. To address this
problem, there is a need for development of diagnostic methods enabling effective determination
of potential toxicity of nanomaterials. On the other hand, developing appropriate test
methods are contingent on identifying the underlying cellular mechanisms of nanomaterial
toxicity. This study reviews toxicity of some of the most widely used nanomaterials. According
to the literature, Iron oxide nanoparticles can augment rate of cell death through oxidative
stress and lipid peroxidation. Exposure to zinc oxide, gold and silver nanoparticles can result
in cell death via mitochondrial dysfunction, expression of abnormal protein in cells, andaltering
the patterns of gene expression, respectively. Likewise, carbon nanotubes can lead to an
increased rate of cell death through the reduction of membrane fluidity, thereby destroying cell
membrane. Our literature review identified a lower toxic effect for nanotubes as compared with
other nano-structures. Regarding the evident high toxicity of nanomaterials, caution must be
exercised in irregular production and use of these substances in the industry. In addition, from
the health and environmental standpoints, carbon nanotubes are the preferable nano-structures
for development of nanotechnologies regarding their lower toxicity in comparison with other
nanomaterials

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