A Review of Toxicity of Some Conventional Nanomaterials

Increased production and use of nanomaterials has led to an ever growing exposure of livingorganisms to these substances. Limited knowledge about possible toxicity of nanomaterialsand their potential to harm living creatures is becoming a serious concern. To address thisproblem, there is a need for development of diagnostic methods enabling effective determinationof potential toxicity of nanomaterials. On the other hand, developing appropriate testmethods are contingent on identifying the underlying cellular mechanisms of nanomaterialtoxicity. This study reviews toxicity of some of the most widely used nanomaterials. Accordingto the literature, Iron oxide nanoparticles can augment rate of cell death through oxidativestress and lipid peroxidation. Exposure to zinc oxide, gold and silver nanoparticles can resultin cell death via mitochondrial dysfunction, expression of abnormal protein in cells, andalteringthe patterns of gene expression, respectively. Likewise, carbon nanotubes can lead to anincreased rate of cell death through the reduction of membrane fluidity, thereby destroying cellmembrane. Our literature review identified a lower toxic effect for nanotubes as compared withother nano-structures. Regarding the evident high toxicity of nanomaterials, caution must beexercised in irregular production and use of these substances in the industry. In addition, fromthe health and environmental standpoints, carbon nanotubes are the preferable nano-structuresfor development of nanotechnologies regarding their lower toxicity in comparison with othernanomaterials