光谱与原子力显微镜方法研究金纳米粒子细胞内吞

发布时间：2018-01-13 22:28

本文关键词：光谱与原子力显微镜方法研究金纳米粒子细胞内吞　出处：《东北师范大学》2015年硕士论文　论文类型：学位论文

【摘要】：与传统的光学探针相比,金纳米粒子作为光学探针有着更好的稳定性和易制备、修饰的特性,并且在光学信号和生物兼容性方面都有着很大的优势,从而使金纳米粒子在生物传感器和生物成像以及在生物医学领域和分析化学领域等方面有着广泛的应用。在单粒子光谱技术与单粒子成像的优势中,金纳米粒子由于本身具有一定的光学特性,进而在单细胞层面上可以与生物功能性分子相结合成为了研究学者们研究细胞的一种有力工具。本论文将紫外-可见吸收光谱技术、原子力显微镜单分子示踪技术结合在一起,研究金纳米粒子与细胞之间存在的细致相互作用,以及金纳米粒子进入细胞的动态过程。具体结果摘要内容如下:1.我们根据金纳米粒子具有的吸收特性,通过采集金纳米粒子吸收光谱来研究,金纳米粒子与细胞之间的相互作用。通过实验发现纳米粒子与细胞孵育以后也会存在一个明显的吸收峰,此吸收峰和不与细胞作用的纳米粒子吸收峰相比有微小的红移。利用离散偶极子近似(discrete dipole approximation-DDA)理论,进行理论模拟,得出了纳米粒子与细胞孵育和纳米粒子单独存在时悬浮溶的液吸收峰。利用高斯拟合,得到吸收峰的峰值位置,理论模拟与我们在实验中所得的吸收光谱值存在5nm的误差,这说明我们的实验是可行的。同时实验结果表明:金纳米粒子与细胞孵育后,其吸收峰会发生红移现象。吸收峰红移说明:纳米粒子周围的介电环境发生了变化,即纳米粒子只有与细胞发生了相互作用,周围的介电环境才会发生变化。同时在纳米粒子浓度降低时,降低的金纳米粒子与细胞孵育后的吸收峰在三个浓度之间没有发生变化。而与单独金纳米粒子的吸收峰相比而言,它发生了吸收峰红移的现象。这充分说明金纳米粒子与细胞孵育以后会使吸收峰发生红移,吸收峰红移的原因是纳米粒子周围的介电环境变化所引起,金纳米粒子周围介电环境变化就充分说明纳米粒子被内吞到细胞内部。2.用原子力显微镜单分子示踪技术记录了不同尺寸的单个金纳米粒子进入到细胞中的动态过程。通过实验我们得出:分别为5nm、10nm、20nm的纳米粒子与细胞作用的内吞力的范围大约在20p N至140p N之间。同时,在纳米粒子的粒径逐渐增大时,纳米粒子与细胞之间的作用力与作用时间会随着纳米粒子与细胞接触面积的增加而增加,同时进入的平均速率会随着进入距离的增大而有所减小。做了对照和阻碍实验,说明纳米粒子与细胞之间存在一种特殊的作用力,而且纳米粒子的内吞是通过细胞质膜上胆固醇的作用,依赖于网格蛋白或小窝蛋白的介导进入细胞内部。以上工作阐明:金纳米粒子与细胞孵育以后,纳米粒子会进入到细胞内部,并且在金纳米粒子进入细胞的过程中,将会与细胞膜上的物质存在一定的关系。实验中根据紫外-可见吸收光谱的峰值变化,表明金纳米粒子被内吞到细胞中。同时我们利用原子力显微镜单分子示踪技术研究不同尺寸单个纳米粒子与细胞作用的动态过程,这一工作为以后研究药物转运具有重要意义。
[Abstract]:Compared with the traditional optical probe and gold nanoparticles as optical probe has better stability and easy preparation, modification and properties on the optical signal and bio compatibility have great advantages, so that the gold nanoparticles have been widely applied in biological sensors and biological imaging and in biomedical field and analysis in the field of chemistry. Single particle spectroscopy and single particle imaging advantage, gold nanoparticles due to its optical characteristics, and biological function and molecular combination of a powerful tool to study cell researchers at the single cell level. The UV Vis absorption spectroscopy technology atomic force microscopy, single molecule tracing technology together between gold nanoparticles and cell detailed interactions, and gold nanoparticles into The dynamic process of cells. The specific results are as follows: 1. according to the absorption properties of gold nanoparticles have, through the acquisition of gold nanoparticles to study the absorption spectra, the interaction between gold nanoparticles and cells. Experiments found that nanoparticles and cells were incubated with after there will be an obvious absorption peak, the absorption peak and not cells with nanoparticles, the absorption peaks are small redshift compared. By using the discrete dipole approximation (discrete dipole approximation-DDA) theory, theoretical simulation, obtained nanoparticles and cells were incubated with nanoparticles alone when suspension solution of liquid absorption. Using Gauss fitting, get the peak position of absorption peak, theoretical simulation of 5nm error our income and absorption spectra in the experiment, it shows that our experiment is feasible. At the same time, the experimental results show that the gold nanoparticles With the cells after incubation, the absorption peak red shift phenomenon. The absorption peak red shift that changes the dielectric environment around the nanoparticles, the nanoparticles only and cell interaction occurs, the dielectric surrounding environment will change at the same time. The concentration of nanoparticles decreased, gold nanoparticles and cells with reduced absorption peak after incubation between three concentration did not change. The absorption peak of gold nanoparticles with single contrast, it happened redshift of absorption peak phenomenon. This fully shows that the gold nanoparticles and cells were incubated after the absorption peak red shifted absorption peak red shift is a dielectric nanoparticles caused by environmental changes gold nanoparticles, around the dielectric environment can fully explain nanoparticle endocytosis to the interior of the cell.2. microscope single molecule tracing technique using atomic force records of different scale A single inch of gold nanoparticles into dynamic processes in the cell. Through experiments, we conclude that: respectively 5nm, 10nm, and 20nm nanoparticles range cell endocytosis capacity between about 20p N to 140P N. At the same time, the particle size increased in force, and action time between nanoparticles and the cell will increase with the increase of nanoparticles and cell contact area, the average rate at the same time will enter into with the increasing distance decreased. The control and block experiment shows that there is a special interaction between nanoparticles and cells, and endocytosis of nanoparticles is through the cytoplasmic membrane cholesterol, depend on clathrin or caveolin mediated entry into cells. The above work of gold nanoparticles and cells following incubation, nanoparticles will enter into cells, and In the process of gold nanoparticles into cells, there is a certain relationship and will be on the cell membrane material. The experiment according to the UV Vis absorption spectra showed that the peak value change, gold nanoparticles is internalized into the cell. The dynamic process at the same time we use the atomic force microscope study of single molecular tracer technique in different sizes of single nanoparticles and cells. The significance of this work for the future research on drug transport.

【学位授予单位】：东北师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：Q25;TB383.1

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