Cytotoxicity and Effects on Cell Viability of Nickel Nanowires

Recently, nickel nanowires (Ni NWs) are finding an increased use in biomedical applications. Like all nanoparticles used in biological studies, their toxicity is an important factor to be considered. In this study, the cytotoxic effects of Ni NWs were investigated in terms of metabolic activity of human colorectal carcinoma cells HCT 116. Ni NWs with an average diameter of 30-34 nm were prepared by electrodeposition in nanoporous alumina templates. The composition of the NWs was determined using energy dispersive X-Ray analysis, whereas their morphology was observed with scanning electron microscopy. Cytotoxicity was quantified by the MTT colorimetric assay, in which the optical signals of the cell-reduced MTT products were measured at 570 nm. Specifically, the effects of NW length, cell exposure time, as well as NW to cell ratio, were evaluated. The results showed that cell metabolic activity is affected by Ni NWs, depending on both exposure time and NW number. These findings demonstrate that different levels of biocompatibility can be obtained with specific doses and properties of Ni NWs and can serve as guideline for future experiments.