Document Type : Original Article
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 is contingent on identifying cellular mechanism underlying toxicity of
nanomaterials. 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, and altering 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.