https://doi.org/10.1140/epje/i2006-10043-y
Regular Article
Wormlike lipid/DNA micelles in a non-polar solvent
Geschwister-Scholl-Platz 1, Ludwig-Maximilians-Universität, D-80539, München, Germany
* e-mail: joachim.raedler@physik.uni-muenchen.de
Received:
13
January
2006
Accepted:
20
September
2006
Published online:
16
October
2006
The phase behavior of DOPE/DOTAP-DNA complexes in phase-separated oil(dodecane)/water mixtures was explored using Small Angle X-Ray Scattering (SAXS) and Fluorescence Correlation Spectroscopy (FCS). Inverse micelles of DNA with cationic-lipid coating were found in the oil phase. Varying the ratio between cationic and neutral lipids a transition from wormlike to spherical structures is observed for both long ( ≈ 75000bp) and short (30-1246bp) DNA. In contrast to lipid/DNA complexes in the water phase, there is no indication of condensed liquid-crystalline structures in the non-polar phase. In fact, FCS measurements on short DNA oligomers complexed with cationic lipid in alkane give clear evidence for monomeric inverse micelles of DNA. Dilution series revealed a critical lower concentration of lipids and DNA for observing lipid/DNA micelles.
PACS: 83.80.Qr Surfactant and micellar systems, associated polymers – / 87.14.Cc Lipids – / 87.14.Gg DNA, RNA – / 87.64.Bx Electron, neutron and X-ray diffraction and scattering –
© EDP Sciences, Società Italiana di Fisica and Springer-Verlag, 2006
