Assessing risks caused by nickel-based nanomaterials: Hazardous factor identification

Abstract

Nanoparticles of nickel (Ni) and its compounds attract a lot of attention bearing in mind their promising innovative properties allowing their use as catalysts, components in electrical appliances, electronic and photonic devices, and materials used in producing medications, diagnostic preparations, and pesticides. Production volumes of these materials in their nano-form are likely to grow rapidly in the nearest future and it involves greater loads created by these nanomaterials on a human body. And we should remember that Ni and its compounds are highly toxic for humans even in their traditional disperse forms. Their toxicity induces oxidative stress, cellular membranes and mitochondria dysfunction, expression of nuclear transcription factors that are responsible for apoptosis, caspases, as well as proto-oncogenes. Leading role in toxicity of Ni-containing nanomaterials obviously belongs to ions of heavy Ni++ being emitted from them since this heavy metal has pro-oxidant properties and influences enzyme activity and gene expression. Cytotoxic effects produced by Ni-containing nanomaterials were revealed in model experiments in vitro performed with suitable cellular cultures that were morphologically and functionally similar to epithelial cells of respiratory and gastrointestinal tract, liver, kidneys, and nervous system; these materials were able to stimulate oxidant stress, influence expression of apoptosis proteins and nuclear transcription factors, induce apoptosis and necrosis. There are data indicating that Ni-containing nanomaterials can produce malignant transforming effects in vitro. All the above mentioned proves that nickel compounds in their nanoform are a new hazardous factor that requires assessing related risks for workers, consumer, and population in general. Our review focuses on analyzing literature sources on cytotoxicity of Ni-containing nanomaterials and their effects produced on molecular-genetic and cellular levels taken over a period starting from 2011.