Here we investigate the cellular uptake mechanism and final intracellular fate of two cationic liposome formulations characterized by similar physicochemical properties but very different lipid composition and efficiency for intracellular delivery of DNA. The first formulation is made of cationic lipid 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) and the zwitterionic helper dioleoylphosphocholine (DOPC), while the second one is made of the cationic 3Î²-[N-(N,N-dimethylaminoethane)-carbamoyl] cholesterol (DC-Chol) and the zwitterionic lipid dioleoylphosphatidylethanolamine (DOPE). Combining pharmacological and imaging approaches we show that both DOTAP-DOPC/DNA and DC-Chol-DOPE/DNA lipoplexes are taken up in Chinese hamster ovary (CHO) living cells mainly through fluid-phase macropinocytosis. Our results also indicate that lipoplex macropinocytosis is a cholesterol-sensitive uptake mechanism. On the other side, both clathrin-mediated and caveolae-mediated endocytosis play a minor role, if any, in the cell uptake. Colocalization of fluorescently tagged lipoplexes and Lysosensor, a primary lysosome marker, reveals that poorly efficient DOTAP-DOPC/DNA lipoplexes are largely degraded in the lysosomes, while efficient DC-Chol-DOPE/DNA systems can efficiently escape from endosomal compartments. Â© 2011 American Chemical Society.
|Titolo:||Cholesterol-dependent macropinocytosis and endosomal escape control the transfection efficiency of lipoplexes in CHN living cells|
|Data di pubblicazione:||2012|
|Parole Chiave:||cationic liposomes; cell transfection; endocytosis; endosomal escape; lipoplexes; lysosome degradation; macropiocytosis; Animals; CHO Cells; Cholesterol; Cricetinae; Cricetulus; DNA; Endosomes; Fatty Acids, Monounsaturated; Fluorescent Dyes; Liposomes; Microscopy, Confocal; Phosphatidylcholines; Phosphatidylethanolamines; Quaternary Ammonium Compounds; Pinocytosis; Transfection; 3003; Molecular Medicine; Drug Discovery3003 Pharmaceutical Science|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1021/mp200374e|
|Appare nelle tipologie:||1.1 Articolo in rivista|