纳米二氧化钛对胃癌细胞电特性的影响

发布时间：2018-05-09 21:03

本文选题：纳米二氧化钛 + 胃癌细胞　；参考：《宁波大学》2017年硕士论文

【摘要】：目的:电阻抗法是基于不同环境下,细胞的电阻和电容随不同的频率变化而改变,是一种非侵入性、实用的技术。本论文以人胃癌细胞MGC803的阻抗特性和细胞悬浮液中纳米二氧化钛的毒性变化对应的阻抗响应为主要研究内容,探讨电阻抗技术在细胞毒性评价研究中的应用。方法:首先设置的电场频率范围是40Hz到100 MHz,使用安捷伦4294A阻抗分析仪和平行板测量池,对人胃癌细胞MGC803和两种浓度纳米二氧化钛悬浮液进行阻抗测量,获得实验数据,然后构建二项式Cole-Cole模型和等效电路模型,提取模型特征参数,应用非线性最小二乘曲线进行拟合分析,最后获得人胃癌MGC803细胞悬浮液的电阻抗谱和Cole-Cole模型差异,比较两种浓度纳米二氧化钛的电阻抗谱特征和解析理论模型参数差异,探讨在实验条件下实现纳米二氧化钛的细胞毒性评价的可行性和具体实施细节。结果:1人胃癌细胞MGC803的电特性具有体积分数依存性,即随着体积分数的增加,电阻抗谱中的电阻抗实部和虚部(Re Z和Im Z)逐渐减小,特征频率(f C1、f C2)几乎不变。2纳米二氧化钛对人胃癌细胞MGC803电特性的影响具有剂量依赖性。即随纳米Ti O2剂量增加,电阻抗增量(△Z1,△Z2)随之减小,具体表现在:150μg/ml和300μg/ml的纳米二氧化钛分别减少第一电阻抗增量(△Z1)的18.18%和39.39%(P0.001),分别减少第二电阻抗增量(△Z2)的6.56%、8.2%(P0.001)。3纳米二氧化钛增加胃癌MGC803细胞的特征频率(f C1、f C2),具体表现:150μg/ml和300μg/ml的纳米二氧化钛分别增加第一特征频率(f C1)的19.74%和29.67%(P0.001),分别增加第二特征频率(f C2)的6.28%、23.43%(P0.001)。4纳米二氧化钛对胃癌细胞MGC803电特性的作用是降低细胞膜和核膜电阻,增加其导电性能。即150μg/ml和300μg/ml的纳米二氧化钛的细胞膜电容(Cm)和细胞膜外电阻(Re)分别减少23.08%和38.46%,8.13%和16.26%,(P0.001),细胞质电阻(Rcyt)细胞质电阻和横跨细胞核两端的细胞质电阻(Rsh)分别增大29.41%和35.29%,4.93%和28.22%(P0.001)。5通过电镜观察发现,300μg/ml纳米二氧化钛在MGC803细胞外堆积,穿过细胞膜,存在细胞质中。结论:本研究利用电阻抗谱技术检测纳米二氧化钛对胃癌细胞株MGC803的毒性作用,并基于数学模型和等效电路模型的参数变化,探讨纳米二氧化钛改变细胞膜和核膜的电阻抗作用机制,为纳米二氧化钛的细胞毒性作用提供一种量化的电学评价方法。
[Abstract]:Aim: the impedance method is a noninvasive and practical technique, which is based on the change of cell resistance and capacitance with different frequencies in different environments. In this paper, the impedance characteristics of human gastric cancer cell line MGC803 and the impedance response corresponding to the change of nano-TiO _ 2 toxicity in cell suspension were studied, and the application of electrical impedance technique in cytotoxicity evaluation was discussed. Methods: the frequency range of electric field was from 40Hz to 100MHz. Using Agilent 4294A Impedance Analyzer and measuring Pool, we measured the impedance of human gastric cancer cell line MGC803 and two kinds of nanometer titanium dioxide suspensions of different concentrations, and obtained the experimental data. Then the binomial Cole-Cole model and the equivalent circuit model were constructed, the characteristic parameters of the model were extracted, and the nonlinear least square curve was used to fit and analyze. Finally, the difference between the impedance spectrum of human gastric cancer MGC803 cell suspension and the Cole-Cole model was obtained. The characteristics of impedance spectrum and the parameters of analytical theoretical model were compared between the two concentrations of nano-TiO _ 2, and the feasibility and implementation details of the cytotoxicity evaluation of nano-TiO _ 2 under experimental conditions were discussed. Results the electrical properties of human gastric cancer cell line MGC803 have volume fraction dependence, that is, with the increase of volume fraction, the impedance real part and imaginary part re Z and Im Z in the impedance spectrum gradually decrease. The effect of nano-TiO _ 2 on the electrical properties of human gastric cancer cell line MGC803 was dose-dependent. That is, the increment of impedance (Z _ 1, Z _ 2) decreases with the increase of TIO _ 2 nanocrystalline dose. The results showed that the proportion of TIO _ 2 at: 150 渭 g/ml and 300 渭 g/ml decreased by 18.18% and 39.39% of the first electrical impedance increment (Z1), respectively, and the second electrical impedance increment (Z2) decreased by 6.56% and 8.2%, respectively. The characteristic frequency of MGC803 cells was increased. The effect of nano-TiO _ 2 on the electrical properties of gastric cancer cell line MGC803 is to increase 19.74% and 29.67% of the first characteristic frequency (f C _ 1) and to increase the second characteristic frequency (f _ C _ 2) by 6.28% and 23.43% P 0.001C _ 4, respectively, in the presence of 1: 150 渭 g/ml and 300 渭 g/ml, respectively, in order to reduce the electrical properties of the cell membrane and nuclear membrane. Increase its electrical conductivity. The membrane capacitance (cm) and the extracellular resistance (Ree) of nanometer titanium dioxide (150 渭 g/ml and 300 渭 g/ml) decreased by 23.08% and 38.46% and 16.26%, respectively, and the cytoplasmic resistance and cytoplasmic resistance across the two ends of the nucleus increased 29.41% and 35.294.93%, respectively, and 28.22%(P0.001).5 increased by 16.26% and 16.26%, respectively. The results of electron microscopic observation showed that 300 渭 g/ml nano-TiO _ 2 accumulated in MGC803 cells. It passes through the cell membrane and is present in the cytoplasm. Conclusion: in this study, the toxicity of nano-TiO _ 2 to gastric cancer cell line MGC803 was detected by means of impedance spectroscopy, and the parameter changes based on mathematical model and equivalent circuit model were used to detect the toxicity of nano-TiO _ 2 to gastric cancer cell line MGC803. To explore the mechanism of nano-TiO _ 2 changing the electrical impedance of cell membrane and nuclear membrane, and to provide a quantitative electrical evaluation method for the cytotoxicity of nano-TiO _ 2.
【学位授予单位】：宁波大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB383.1;R73-3

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