| 题名 | 原代星形胶质细胞在纳米银与银离子毒性差异研究中的应用 |
| 作者 | 孙成 |
| 学位类别 | 硕士 |
| 答辩日期 | 2015-05 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 周群芳 |
| 关键词 | 纳米银 银离子 星形胶质细胞 神经毒性 生物安全性，Silver Nanoparticles Silver ions Astrocytes Neurotoxicity Biosafety |
| 其他题名 | Application of astrocytes primary cultures in the evaluation for toxicity difference between silver nanoparticles and silver ions |
| 学位专业 | 环境工程 |
| 中文摘要 | 纳米银由于其优良的抗菌性能、独特的理化性质已被广泛应用于多个领域，因此其潜在的环境暴露风险值得人们关注。目前针对纳米银的生物安全性与毒性效应已有 较多的研究报道，然而关于纳米银的毒性机制仍众说纷纭，没有定论。本文通过建立原代星形胶质细胞模型，研究纳米银的细胞毒性效应，并探讨了其与银离子毒性 作用的差异。 首先，本文在对传统细胞培养方法优化的基础上，建立了大鼠大脑皮层星形胶质细胞原代培养物实验模型。该星形胶质细胞模型具有纯度高、易于培养，能够进行稳 定传代的特点，满足毒理学实验的需求。 应用星形胶质细胞，本文开展了聚乙烯吡咯烷酮包被的纳米银与银离子的毒性差异研究。结果表明，纳米银暴露可引起剂量相关式细胞活力抑制，但对细胞膜并没有 损伤作用。纳米银可诱导细胞产生活性氧化物，引起c-Jun氨基末端激酶（JNK）磷酸化，进而导致细胞发生凋亡现象。利用蛋白芯片技术分析发现，纳米银 暴露引起星形胶质细胞多个细胞因子释放增加，表明其具有潜在的神经免疫毒性。与纳米银的毒性相比，银离子具有更强的毒性效应。银离子暴露可以导致胞外乳酸 脱氢酶（LDH）含量增加，说明它可通过破坏细胞膜对细胞产生毒性作用。银离子刺激并不引起胞内活性氧化物（ROS）发生变化。结合流式细胞术的分析发 现，银离子主要通过诱导细胞发生坏死而产生细胞毒性。 总之，基于星形胶质细胞模型的研究显示，纳米银可诱导细胞凋亡，引起神经毒性效应，而银离子则主要诱导细胞发生坏死，因此银离子释放不是纳米银产生毒性的 唯一机制，纳米银本身的颗粒效应与其毒性作用密切相关。本论文研究结果为纳米银的生物安全性评价提供了基础数据支撑。另外，星形胶质细胞原代培养物作为一 种灵敏稳定的神经细胞模型可有效应用于纳米材料的神经毒性效应与作用机制研究中。 |
| 英文摘要 | Silver nanoparticles (AgNPs) are used widely in various fields due to their excellent antibacterial effect, thus increasing the risk of the environmental exposure. The biosafety and biological effects of AgNPs are being highly concerned. In this study, primary astrocytes model is established to study the neurotoxicity of AgNPs and the toxicity difference between AgNPs and silver ion is discussed. Firstly, the cell model of the rat cerebral astrocytes primary clutures is established by optimizing the traditional cell culture methods. It’s easy to culture the astrocytes with high purity and it can meet the requirements of the toxicological experiments with passage stability. The primary cultures of astrocytes are applied to study the different toxicities induced by PVP coated AgNPs and silver ions. The results show that AgNPs can inhibit the cell viability in a dose related manner, while the cell membrane integrity is not damaged. Meanwhile, AgNPs can induce cell apoptosis by inducing intracellular Reactive Oxygen Reactive (ROS) generation and c-Jun N-terminal Kinase (JNK) phosphorylation. Using protein chip technology, AgNPs are found to increase the release of multiple cell cytokines from astrocytes, showing AgNPs may induce potential neuroinflammation. Silver ions are much more toxic when compared to AgNPs according to EC50 from Alarmar Blue assay. Silver ions can increase the release of extracellular Lactate Dehydrogenase (LDH), showing the cell membrane integrity is compromised by ionic silver exposure. Silver ions have no effect on intracellular ROS generation or JNK phosphorylation. Flow cytometry analysis shows that silver ion predominantly induce necrosis in astrocytes. In summary, AgNPs can cause obvious toxicological effects on the astrocytes through inducing cell apoptosis, while silver ion exposure mainly cause cell necrosis. Accordingly, the release of silver ions is not the unique mechanism for AgNPs induced toxicity and the particle specific effects need to be considered. The results provide the useful scientific data for the evaluation of the toxicological effects of AgNPs and the biosafety of this nanomaterial in the daily supplies need to be concerned. In addition, the primary cultures of astrocytes can be applied as a sensitive feasible cell model to study the neurotoxicities of nanoparticles. |
| 内容类型 | 学位论文 |
| 源URL | [http://ir.rcees.ac.cn/handle/311016/34510]  |
| 专题 | 生态环境研究中心_环境化学与生态毒理学国家重点实验室 |
| 推荐引用方式 GB/T 7714 | 孙成. 原代星形胶质细胞在纳米银与银离子毒性差异研究中的应用[D]. 北京. 中国科学院研究生院. 2015. |
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