RT Journal Article
T1 Gene vectors based on DOEPC/DOPE mixed cationic liposomes: a physicochemical study
A1 Muñoz Úbeda, Mónica
A1 Rodríguez-Pulido, Alberto
A1 Nogales, Aurora
A1 Llorca, Oscar
A1 Quesada-Pérez, Manuel
A1 Martín-Molina, Alberto
A1 Aicart Sospedra, Emilio
A1 Junquera González, María Elena
AB A double approach, experimental and theoretical, has been followed to characterize from a physicochemical standpoint the compaction process of DNA by means of cationic colloidal aggregates. The colloidal vectors are cationic liposomes constituted by a mixture of a novel cationic lipid, 1,2-dioleoyl-sn-glycero-3-ethylphosphocholine (chloride salt) (DOEPC) and a zwitterionic lipid, the 1,2-dioleoyl-sn-glycero-3-phosphatidylethanolamine (DOPE). A wide variety of high precision experimental techniques have been used to carry out the analysis: electrophoretic mobility, small-angle X-ray scattering (SAXS), cryogenic transmission electron microscopy (cryo-TEM) and fluorescence spectroscopy (ethidium bromide intercalation assays). On the other hand, a theoretical model that considers the renormalization of charges of both the polyelectrolyte and the colloidal aggregates sheds light as well on the characteristics of the compaction process. This global information reveals that the compaction of DNA by the cationic liposomes is mostly driven by the strong electrostatic interaction among the positively charged surfaces of the colloidal aggregates and the negatively charged DNA, with a potent entropic component. DOEPC/DOPE liposomes are mostly spherical, with a mean diameter of around 100 nm and a bilayer thickness of 4.4 nm. From a morphological viewpoint, an appreciable amount of multilamellar structures has been found not only on the lipoplexes but also on the parent liposomes. The isoneutrality of the lipoplexes is found at liposome/DNA mass ratios that decrease with the molar fraction of cationic lipid in the mixed liposome (a). This liposome composition has a clear effect as well on the lipoplex structure, which goes from an inverted hexagonal phase (HII), usually related to improved cell transfection efficiency, at low cationic lipid molar fraction (a z 0.2), to a lamellar structure (La) when the cationic lipid content in the mixed liposomes increases (a $ 0.4), irrespective of the lipoplex charge ratio. On the other hand, a theoretical complexation model is employed to determine the net charge of the lipoplexes studied in this work, by using renormalized charges. The model allows us to confirm and predict the experimental isoneutrality conditions as well as to determine the maximum magnitude of this charge as a function of the composition of the resulting lipoplexes.
PB Royal Society of Chemistry
SN 1744-683X
YR 2011
FD 2011
LK https://hdl.handle.net/20.500.14352/91130
UL https://hdl.handle.net/20.500.14352/91130
LA eng
NO Muñoz-Úbeda, Mónica, et al. «Gene Vectors Based on DOEPC/DOPE Mixed Cationic Liposomes: A Physicochemical Study». Soft Matter, vol. 7, n.o 13, 2011, p. 5991. https://doi.org/10.1039/c1sm05352c.
DS Docta Complutense
RD 18 mar 2026