A new method that nanometer-liposomes could penetrate the cell membrane to deliver their encapsulated material into cells was investigated.Nanometer sized-liposomes were produced from phosphatidylcholine to encapsulate fluorescent dyes and FITC labeled superoxide dismutase(SOD-FITC) by an ultrasonic method.The size distribution of liposomes was determined with a Laser Particle Analyser.The fluorescence images demonstrate that liposomes can transfer fluorescent dyes(FITC,Rhodamine B),which are not cell membrane permeable,into cells.Single cell analysis of the delivered SOD-FITC with microchip electrophoresis revealed that the density of liposomes and interaction-time between liposomes and cells affected the efficiency of intracellular delivery of encapsulated material.
