Coppola S, Pozzi D, De Sanctis S Candeloro, Digman M A, Gratton E, Caracciolo G
Methods Appl Fluoresc. 2013;1(1). doi: 10.1088/2050-6120/1/1/015005.
Spatio-temporal image correlation spectroscopy (STICS) is a powerful technique for assessing the nature of particle motion in complex systems although it has been rarely used to investigate the intracellular dynamics of nanocarriers so far. Here we introduce a method to characterize the mode of motion of nanocarriers and to quantify their transport parameters on different length scales from single-cell to subcellular level. Using this strategy we were able to study the mechanisms responsible for the intracellular transport of DOTAP-DOPC/DNA and DC-Chol-DOPE/DNA lipoplexes in CHO-K1 live cells. Measurement of both diffusion coefficients and velocity vectors (magnitude and direction) averaged over regions of the cell revealed the presence of distinct modes of motion. Lipoplexes diffused slowly on the cell surface (diffusion coefficient, ≈ 0.003 µm/s). In the cytosol, the lipoplexes' motion was characterized by active transport with average velocity ν ≈ 0.03 µm/s and random motion. The method permitted us to generate intracellular transport map showing several regions of concerted motion of lipoplexes.
时空图像相关光谱技术（STICS）是一种用于评估复杂系统中粒子运动性质的强大技术，尽管到目前为止它很少被用于研究纳米载体的细胞内动力学。在此，我们介绍一种方法，用于表征纳米载体的运动模式，并在从单细胞到亚细胞水平的不同长度尺度上量化其转运参数。使用这种策略，我们能够研究负责DOTAP-DOPC/DNA和DC-Chol-DOPE/DNA脂质体在CHO-K1活细胞内转运的机制。对细胞区域平均的扩散系数和速度矢量（大小和方向）的测量揭示了不同运动模式的存在。脂质体在细胞表面扩散缓慢（扩散系数，≈0.003 µm/s）。在细胞质中，脂质体的运动以平均速度ν≈0.03 µm/s的主动转运和随机运动为特征。该方法使我们能够生成细胞内转运图谱，显示脂质体协同运动的几个区域。
