[In Vitro Cytotoxicity Study of Nickel Ion]

The purpose of this study was to investigate the cytotoxicity of the nickel ion and provide with basic data for the biological evaluation of those medical devices containing nickel. Seven cell lines were chosen. They were L929, h9c2(2-1), 293[HEK-293], hFOB1.19, THLE-3, H9 and IM-9 respectively. According to the principle of biological evaluation of medical devices, MTT method was chosen to test the cytotoxicity in different concentrations of nickel ion. For each cell line, the relative growth rate (RGR) was obtained and the cytotoxic grade was classified. Besides, IC50 values were calculated. As a result, it was found that the sensitivity was different among all cell lines. H9 was the most sensitive one, while the L929 was the most tolerant one. The concentration which is not above 1.25 mg/L was safe for all seven cell lines, because the cytotoxicity for all cells exposed in this concentration were not higher than grade 1. According to the criteria for medical devices, the concentrations not above 5 mg/L were safe for L929 cells. This result helps us to roughly assess the cytotoxicity and systematic toxicity caused by nickel contained in medical devices.