A Review of Toxicity of Some Conventional Nanomaterials

Abstract

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