title: Transfection efficiency boost of cholesterol-containing lipoplexes.
abstract: Most lipid formulations require cholesterol for successful transfection, but the precise reason remains to be more clearly understood. Here, we have studied the effect of cholesterol on the transfection efficiency (TE) of lipoplexes in vitro. Addition of cholesterol to highly effective DC-Chol-DOPE/DNA lipoplexes increases TE, with 40 mol% cholesterol yielding about 10-fold improvement. The transfection mechanisms of cholesterol-containing lipoplexes have been investigated by combining dynamic light scattering, synchrotron small angle X-ray scattering, laser scanning confocal microscopy and transfection efficiency measurements. Our results revealed that cholesterol-containing lipoplexes enter the cells partially by membrane fusion and this mechanism accounts for efficient endosomal escape. We also found evidence that formulations with high cholesterol content are not specifically targeted to metabolic degradation. These studies will contribute to rationally design novel delivery systems with superior transfection efficiency.
authors.affiliation: Department of Molecular Medicine, Sapienza University of Rome, Rome, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Pozzi
authors.forename: Cristina
authors.initials: C
authors.lastname: Marchini
authors.forename: Francesco
authors.initials: F
authors.lastname: Cardarelli
authors.forename: Heinz
authors.initials: H
authors.lastname: Amenitsch
authors.forename: Chiara
authors.initials: C
authors.lastname: Garulli
authors.forename: Angelo
authors.initials: A
authors.lastname: Bifone
authors.forename: Giulio
authors.initials: G
authors.lastname: Caracciolo
mesh_terms: D000818:Animals; D001703:Biophysics / Q000379:methods*; D016466:CHO Cells; D002784:Cholesterol / Q000031:analogs & derivatives / Q000737:chemistry*; D006224:Cricetinae; D011992:Endosomes / Q000378:metabolism; D007834:Lasers; D008027:Light; D008081:Liposomes / Q000737:chemistry; D018613:Microscopy, Confocal / Q000379:methods; D049329:Nanostructures / Q000737:chemistry; D010714:Phosphatidylethanolamines / Q000737:chemistry; D010873:Pinocytosis; D012542:Scattering, Radiation; D053838:Scattering, Small Angle; D014162:Transfection; D014965:X-Rays
chemical_list: D008081:Liposomes; D010714:Phosphatidylethanolamines; C070648:3-(N-(N',N'-dimethylaminoethane)carbamoyl)cholesterol; C094877:dioleoyl phosphatidylethanolamine; D002784:Cholesterol