Efficiency of cytoplasmic delivery by non-cationic liposomes to cells in vitro: A confocal laser scanning microscopy study

It is necessary to understand liposomal uptake mechanisms and intracellular distribution in order to design more efficient gene (drug) carrier systems. Until now, a few studies have been carried out using confocal laser scanning microscopy (CLSM) to investigate the cellular uptake and transfection mediated with liposomes. So, by CLSM, we demonstrated that artificial virus-like envelope (AVE) vesicles labeled with rhodamine-PE (Rh-PE), carbocyanine (DiI) and carboxyfluorescein (CF) were investigated into the cytoplasm of two human cell lines, Mewo (human melanoma cell line) and HepG2 (human hepatoma cell line) cells grown in DMEM medium supplemented with different percentages (0%, 30%, and 100%) fetal calf serum (FCS). The liposome uptake was dependent on the cell line, in view that the whole process of liposomes associated with cells (uptake) is a two-step process involving binding and endocytosis. Based upon the various assays used to measure cellular uptake of liposomes, we conclude the efficacy of cytoplasmic delivery by AVE-liposomes to cells in culture.