中文摘要：

目的：比较不同镀膜钕铁硼磁体对L929小鼠成纤维细胞的增殖及凋亡的影响,以评价其细胞毒性。方法：制备100%、50%、25%这3种浓度未镀膜钕铁硼磁体,氮化钛（TiN）镀膜钕铁硼磁体,类金刚石（DLC）镀膜钕铁硼磁体浸提液。以上述9组浸提液和阴性对照液,阳性对照液分别进行L929小鼠成纤维细胞培养后以MTT法检测各组细胞相对增殖率。采用流式细胞仪AnnexinV-FITC/PI双染法检测不同镀膜磁体组中正常活细胞和凋亡细胞数量差异。结果：MTT结果显示TiN组、DLC组、未镀膜组、阳性对照组的细胞毒性分别为1级,0～1级,2级,4级。流式细胞仪散点图显示,空白对照组中以正常活细胞为主;DLC组和TiN组中主要为正常细胞和早期凋亡细胞;未镀膜组中主要为早期凋亡和晚期凋亡、坏死细胞。结论：未镀膜钕铁硼磁体具有一定的细胞毒性,TiN镀膜和DLC镀膜磁体的细胞毒性符合细胞毒性测验制定的安全标准。

英文摘要：

Objective： To evaluate the cytotoxicity of NdFeB magnet with different coatings through investigating its effect on the proliferation and apoptosis of L929 mouse fibroblast cells. Methods： Three groups of magnets--bare magnets, magnets with TiN coating and DLC coating were immersed in the DMEM culture medium to produce 3 kinds of extract liquid. Each extract liquid was diluted into 3 different concentrations （ 100~, 50~~, 25~）. L929 mouse fibroblast cells were cultivated with the 9 extract liquids mentioned above, negative control liquid and positive control liquid, respectively. MTT assay was used to calculate relative growth rate（RGR） ; flow cytometry and An- nexin V--FITC/PI double staining method were utilized to identify and distinguish viable cells, early apoptotic cells and late apoptotic or dead cells. Results： MTT assay showed the cytotoxicity of magnets with TiN coating ranked the level of 1. Magnets with DLC coating ranked between 0 and 1. Bare magnets ranked the level of 2, positive con- trol group ranked the level of 4. Cell distribution scatter diagrams demonstrated that ceils were mainly consisted of viable cells in negative control group whereas early apoptic cells and viable cells made up the main cell portions in TiN coating and DLC coating group. In bare magnets group the apoptic cells and dead cells made up the major pro- portion of the cells. Conclusion： The cytotoxicity of both magnets with TiN coating and DLC coating are acceptable and meet the safty-- use criterion of cytotoxicity tests, while the cytotoxicity of bare NdFeB magnet is unacceptable.