The plasma membrane, which is a phosphoglyceride bilayer at the outer edge of the cell, plays diverse and important roles in biological systems. Visualization of the plasma membrane in live samples is important for various applications in biological functions. We developed an amphiphilic two-photon (TP) fluorescent probe (THQ-Mem) to selectively monitor the plasma membrane in live samples. This probe exhibited red emission (620-700 nm), large TP absorption cross sections (δmax > 790 GM), and high selectivity to the plasma membrane. In cultured cells and in vivo hepatic tissue imaging, THQ-Mem showed bright TP-excited fluorescence (TPEF) and remarkable selectivity for the plasma membrane. Furthermore, simultaneous in vivo imaging with THQ-Mem and a TP lipid droplet probe could serve as an efficient tool to monitor morphological and physiological changes in the plasma membrane and lipid droplets.
This study was supported by grants from the National Leading Research Lab Program of the National Research Foundation of Korea (NRF), funded by the Korean government (MSIP) (NRF-2022R1A2B5B03001607), Center for Convergence Research of Neurological Disorders (NRF-2019R1A5A2026045), Basic Science Research Program (NRF-2021R1A6A1A10044950), and the Ajou University Research Fund. I.-J. L. received a grant from the Basic Science Research Capacity Enhancement Project (NRF-2021R1A6C103B407) and the Korea Basic Science Institute (National Research Facilities and Equipment Center) grant funded by the Ministry of Education (No. 2019R1A6C1010003).
