A Novel “Double-Responsive” and “Dual-Targeted” Multifunctional Fluorescent Probe Monitors the Level Changes of ONOO– in Mitochondria during Cell Pyroptosis

Pyroptosis, often referred to as inflammatory necrosis, is a type of programmed cell death, characterized by the swelling of cells until the cell membranes rupture, resulting in the release of intracellular substances and a strong inflammatory response. Lipid droplets and mitochondria play important roles in cellular activities. A strong correlation exists between pyroptosis and mitochondrial dysfunction, which can be reflected through physiological functions and involves changes in the mitochondrial microenvironment and morphology. In this work, a "double-responsive" and "dual-targeted" fluorescent probe named WD-2 was constructed. It has excellent response performance to viscosity and ONOO^-, and can simultaneously monitor the relevant levels in lipid droplets and mitochondria. Its remarkable targeting ability toward mitochondria and lipid droplets has been verified through colocalization experiments. In cell imaging experiments, the interaction between mitochondria and lipid droplets during nutritional stress was preliminarily studied. With the help of doxorubicin hydrochloride, the changes in the level of ONOO^- in mitochondria during pyroptosis were explored, providing a new perspective for understanding the mechanism of this process.