镀氮化钛膜钕铁硼磁体细胞毒性的实验研究

目的：观察镀氮化钛膜N48钕铁硼磁体对小鼠L929成纤维细胞生长和凋亡的影响,评价该材料的生物相容性。方法：将镀氮化钛膜及未镀膜的钕铁硼磁体、普通托槽加入RPMI-1640培养液中,制备浸提液。分别用阴性、阳性对照液,以及100%、50%、25%镀氮化钛膜样品的浸提液培养小鼠L929成纤维细胞,通过MTT法检测细胞增殖活力,并计算相对增殖率。采用流式细胞仪Annexin V/PI双染法检测观察阴性对照液、100%氮化钛膜及未镀膜的钕铁硼磁体浸提液组细胞的散点图,并计算各组正常、早期凋亡、晚期和坏死细胞的比例。采用SPSS11.5软件包对结果进行配对t检验。结果：镀氮化钛膜磁体的细胞毒性为0～1级;未镀膜磁体的细胞毒性为2级。流式细胞仪散点图发现,空白对照和镀氮化钛膜磁体组散点图显示大量的活细胞集中于左下象限;未镀膜磁体组散点图显示右下象限有大量的早期凋亡细胞。镀氮化钛膜磁体组与空白对照组之间活细胞、早期凋亡、晚期凋亡及坏死细胞含量差异无统计学意义（P〉0.05）;未镀膜磁体组与空白对照组之间不同时期的细胞含量差异有显著性（P〈0.01）。结论：镀氮化钛膜钕铁硼磁体有良好的生物相容性。

The cytotoxicity of N48 NdFeB magnets coated with titanium-nitride

PURPOSE: To evaluate the effect of N48 NdFeB magnets coated with titanium-nitride on the growth and apoptosis of L929 mouse fibroblast cells, and to determine the material biocompatibility. METHODS: The NdFeB magnets coated with titanium-nitride, bare NdFeB magnets and ordinary brackets were put into RPMI-1640 to prepare fusions. L929 mouse fibroblast cells were cultivated in the negative control liquid, positive control liquid, 100%, 50% and 25% sample fusions, respectively. The cell proliferation vitality was detected by MTT assay and the relative growth rate was calculated.Cell scatter diagrams of the negative control liquid, 100% titanium-nitride coated magnets fusion and bare magnets fusion were detected by flow cytometry Annexin V/PI double staining method. The ratios of normal cells, early apoptosis, advanced apoptosis and necrosis cells were calculated. The results were analyzed for paired t test using SPSS11.5 software package. RESULTS: The toxic levels of N48 NdFeB coated with titanium-nitride were ranked as 0-1. The toxic levels of bare magnets were ranked as 2. The cell scatter diagrams showed that there was no significant difference in living cell, early apoptosis and necrosis between magnets coated with titanium-nitride and control group. But there was significant difference between the bare magnets group and control group. CONCLUSION: The N48 NdFeB magnets coated with titanium-nitride have good biocompatibility.