Evaluation of the Effectiveness of Superoxide Dismutases Mediated by Liposomes for Reducing Intracellular Oxidative Stress Using Microchip Electrophoresis with Laser-Induced Fluorescence

Superoxide dismutases (SOD) can be used as anti-oxidization drugs and can eliminate superoxide radicals to protect cells from damage induced by free radicals. However, because of their large molecular weight and impermeability to cell membrane, their drug effectiveness is greatly reduced. Fluorescent microscopy images of cells demonstrated that nano-liposome could transfer SOD into cells. The anti-oxidization action of liposome-mediated SOD has been evaluated by the determination of the fluorescent intensity of intracellular reactive oxygen species (ROS) and reduced glutathione (GSH) in single cells by microchip electrophoresis with laser-induced fluorescence. It has been observed that intracellular ROS decreased and GSH increased after incubation with SOD encapsulated liposomes for 2 hours when compared with direct incubating cells with SOD. The results demonstrate that the drug effectiveness of SOD for reducing intracellular oxidative stress is significantly improved by the delivery of SOD mediated by liposomes.