Department of Chemistry, Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Tsinghua University.
Department of Chemistry, Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Tsinghua University;
J Vis Exp. 2021 Mar 5(169). doi: 10.3791/61603.
Analyzing the diffusional dynamics of nanoparticles on cell membrane plays a significant role in better understanding the cellular uptake process and provides a theoretical basis for the rational design of nano-medicine delivery. Single particle tracking (SPT) analysis could probe the position and orientation of individual nanoparticles on cell membrane, and reveal their translational and rotational states. Here, we show how to use traditional dark-field microscopy to monitor the dynamics of gold nanorods (AuNRs) on live cell membrane. We also show how to extract the location and orientation of AuNRs using ImageJ and MATLAB, and how to characterize the diffusive states of AuNRs. Statistical analysis of hundreds of particles show that single AuNRs perform Brownian motion on the surface of U87 MG cell membrane. However, individual long trajectory analysis shows that AuNRs have two distinctly different types of motion states on the membrane, namely long-range transport and limited-area confinement. Our SPT methods can be potentially used to study the surface or intracellular particle diffusion in different biological cells and can become a powerful tool for investigations of complex cellular mechanisms.
分析纳米粒子在细胞膜上的扩散动力学对于更好地理解细胞摄取过程具有重要意义，并为合理设计纳米药物输送提供了理论基础。单粒子跟踪（SPT）分析可以探测细胞膜上单个纳米粒子的位置和取向，并揭示其平动和转动状态。在这里，我们展示了如何使用传统暗场显微镜来监测金纳米棒（AuNRs）在活细胞膜上的动力学。我们还展示了如何使用 ImageJ 和 MATLAB 提取 AuNRs 的位置和取向，以及如何表征 AuNRs 的扩散状态。数百个粒子的统计分析表明，单个 AuNR 在 U87 MG 细胞膜表面表现为布朗运动。然而，单个长轨迹分析表明，AuNR 在膜上有两种明显不同的运动状态，即长程输运和有限区域限制。我们的 SPT 方法可用于研究不同生物细胞表面或细胞内颗粒的扩散，并且可以成为研究复杂细胞机制的有力工具。
