Revealing the dynamics of a mitochondrial microenvironment during apoptosis under two-photon fluorescence lifetime microscopy using a cyclic iridium(iii) complex

Abstract

Mitochondrion-mediated apoptosis is a major mode of cell death and is inextricably linked to various pathological processes such as tumorigenesis. However, there is still a paucity of non-toxic tools that can visually and dynamically monitor the onset and progression of apoptosis. Herein, we rationally developed a mitochondrial viscosity-sensitive two-photon fluorescent probe (Mito-Ap) to reflect apoptosis. The apoptotic process was accurately detected by two-photon fluorescence lifetime imaging in real-time. In addition, we have successfully demonstrated that the probe can be used to distinguish tumour tissue cells from normal tissue through microenvironmental differences. This work provides a new possibility of directly monitoring the apoptotic process at the cellular level.