A Review of Toxicity of Some Conventional Nanomaterials

Abstract

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