SPECIFIC INVIVO FLUORESCENT DNA STAINING USING LIPOSOME ENTRAPPED DYES

We have investigated the "in vitro" plasma stability, the "in vivo" clearance and the intrahepatic uptake of large unilamellar vesicles (0.2-mu-m) encapsulating carboxifluorescein or the DNA-fluorescent dye, propidium iodide. Liposomes with different lipidic composition achieved a high stability in plasma and they were quickly cleared (90%) from blood circulation one hour after intravenous injection. Administration i.v. of liposomes encapsulating propidium iodide was efficient to stain the nuclei of cells with ability to liposome uptake while free-propidium iodide failed to stain cell-nuclei. In addition, a differential intrahepatic liposome uptake was shown as a function of lipid composition.