Lipid Membrane Alterations in Tumor Spheroids Revealed by Fluorescence Lifetime Microscopy Imaging

作者：Xiao Peng, Jingwen Huang, Mingyue Li, Zaozao Chen, Wei Yan, Junle Qu · 发表于：Analytical Chemistry · 年份：2022 · DOI：10.1021/acs.analchem.2c05126 · 被引用次数：11 · 研究领域：Advanced Fluorescence Microscopy Techniques、Cell Image Analysis Techniques、Photoacoustic and Ultrasonic Imaging

animal models than cells in 2D cultures. Tumor spheroids have been widely used in preclinical experiments of anticancer drug treatments, providing reliable data in pathogenetic research. Currently, different 3D cell culture conditions, even in the same cell line, generate heterogeneous spheroids in morphology and size, resulting in different growth rates or drug-killing responses. Therefore, the measurement and evaluation of the properties of tumor spheroids have become highly demanding tasks with huge challenges. For functional characterization of tumor spheroids, the microenvironment sensitivity and quantitative properties of the fluorescence lifetime microscopy imaging (FLIM) technique have great advantages for improving the reliability of cell physiological testing. In this paper, we have proposed a FLIM-based approach to observe the lipid components labeled with Nile red of cells in both 3D and 2D cultures. The imaging data and analysis provided basic information on the sizes, morphologies, and cell membrane fluorescence lifetime values of the tumor spheroids. FLIM data showed that the microenvironment of the cell membrane in the 3D model was largely altered compared to that in the 2D culture. Next, a series of parameters that may influence the lipid components of tumor cells and tumor spheroids were tested by FLIM, including pH, viscosity, and polarity. The results showed that pH and viscosity contributed little to the change in fluorescence lifetime values, while the c...