Developing Counting System Of Dark-field Imaging Based On Functionalized Gold Nanoparticles For Monitoring Endocytosis And Exocytosis Of Nanoparticles

With the rapid development of nanotechnology,the biological safety performance of nanomaterials has also become the focus of attention.In the living environment,people will inevitably come into contact with various nanomaterials.Nanoparticles have unique physical and chemical properties and biodynamic behaviors due to their particle size in the transition area between macroscopic particles and atomic clusters.Therefore,the study of the interaction between nanomaterials and organisms is particularly important.In this paper,the dark field microscopic imaging technology is used to monitor the endocytosis and exocytosis of gold nanoparticles by cells in real time,and a dark field imaging automatic identification and counting system is constructed to quantitatively analyze gold nanoparticles in cells.At the same time,through the functional modification of gold nanoparticles,the influence of the aggregation state of gold nanomaterials on cell efflux and cytotoxicity was studied,and the following main conclusions were drawn:(1)The dark field pictures collected show that the surface modification of the nanomaterials affects the endocytosis of the cells,and that a large number of aggregated gold nanoparticles in the cells are not easily discharged outside the cells.(2)According to the characteristics of the image,a dark field imaging automatic recognition and counting system was successfully constructed.This algorithm setting is divided into four parts,including color space conversion,brightness threshold setting,image segmentation and color analysis.The system was used to quantitatively analyze the endocytosis and efflux of gold nanoparticles.At the same time,the endocytosis and efflux of gold nanoparticles were quantitatively detected by ICP-MS.The detection results of the two methods are highly consistent.(3)The cell viability,apoptosis and ROS level of two kinds of gold nanoparticles in different aggregation states were tested.The experimental results show that the aggregation of gold nanoparticles makes it difficult for the cells to be discharged to the outside of the cells.The experimental results show that the aggregation of gold nanoparticles makes it difficult for the cells to be discharged to the outside of the cells.The gold nanoparticles trapped in the cells will produce cytotoxicity and affect the viability of the cells.At the same time,the long-term retention of gold nanoparticles will cause early apoptosis,and apoptosis is closely related to the rise of ROS levels.