纳米氧化锌对人肺腺癌细胞A549的毒性

Cytotoxicity of ZnO nanoparticles in human lung cancer cell lines A549

探讨纳米氧化锌(ZnO)对体外培养的人肺腺癌细胞A549的生物学效应.使用原子力显微镜(AFM)、透射电镜(TEM)和X射线衍射仪(XRD)研究纳米ZnO颗粒物的理化性质.然后,使用0mmol/L、0.1mmol/L、0.5mmol/L、1mmol/L、5mmol/L、10mmol/L的纳米ZnO处理体外培养的人肺腺癌A549细胞,MTT法测定细胞生长活性.并且测定1mmol/L纳米ZnO染毒24h后细胞培养液上清中,乳酸脱氢酶(LDH)和胞内的超氧化物歧化酶(SOD)、过氧化氢酶(CAT)的活性,以及丙二醛(MDA)的含量.使用透射电镜和流式细胞仪检测细胞凋亡的情况.荧光染色检测细胞产生活性氧(ROS)的生成.实验所用的ZnO纳米颗粒为长75nm、直径20nm的针状纤锌矿晶体.细胞实验结果表明,纳米ZnO颗粒对A549细胞的生长活性具有明显的抑制作用,存在剂量-效应关系.培养液上清中LDH活性显著升高(P<0.05),胞内CAT活性显著下降、MDA含量显著升高(P<0.01),但SOD活性下降不明显.荧光染色检测发现染毒后A549细胞出现细胞凋亡,而且细胞内ROS的生成与纳米ZnO存在剂量-效应关系.结论是纳米氧化锌诱导人肺腺癌A549细胞产生活性氧,引发细胞凋亡,并产生细胞毒性.

The aim of the study was to investigate the toxic effects of nanosized ZnO in Vitro. Characterization of ZnO nanoparticles was carried out by atomic force microscope （AFM）, transmission electron microscope （TEM） and X-ray diffraction （XRD）. In this study, lung cancer cell lines A549 were exposed to 0mmol/L, 0.1mmol/L, 0.Smmol/L, lmmol/L, 5mmol/L, 10mmol/L of ZnO nanoparticles, respectively. MTF assay was performed to evaluate the viabilities of ZnO-treated cells after 12 h, 24 h, 36 h and 48 h exposure. The activities of lactate dehydrogenase （LDH）, cellular superoxide dismutase （SOD）, catalase （CAT）, and malondialdehyde （MDA） were determined after exposure to l mmol/L ZnO for 24h. Moreover, apoptotic characteristics and reactive oxygen species （ROS） production in A549 cells were measured. ZnO nanoparticles were needlelike crystals （75nm length; 20nm diameter）. The viability of A549 cells were reduced after being exposed to ZnO nanoparticles in a dose-dependent manner. The activities of LDH and the levels of MDA were significantly increased（ P 〈 0.05, P 〈 0.01）, respectively. However, the activities of CAT were significantly decreased（ P 〈 0.01 ）. No significant difference in the activities of SOD was observed between the ZnO-treated cells and the controls. ZnO nanoparticles at lmmol/L induced apoptosis in A549 cells. The levels of ROS in ZnO-treated cells were significantly higher than those in controls. These results suggested that ZnO nanoparticles could result in apoptosis in A549 cells through oxidative stress.