Europhys. Lett.
Volume 67, Number 4, August 2004
Page(s) 669 - 675
Section Interdisciplinary physics and related areas of science and technology
Published online 01 August 2004
Europhys. Lett., 67 (4), pp. 669-675 (2004)
DOI: 10.1209/epl/i2004-10091-y

Evidence of an inverted hexagonal phase in self-assembled phospholipid- $\chem{DNA}$-metal complexes

O. Francescangeli1, M. Pisani2, V. Stanic1, P. Bruni2 and T. M. Weiss3

1  Dipartimento di Fisica e Ingegneria dei Materiali e del Territorio and INFM Università Politecnica delle Marche - Via Brecce Bianche, 60131 Ancona, Italy
2  Dipartimento di Scienze dei Materiali e della Terra, Università Politecnica delle Marche - Via Brecce Bianche, 60131 Ancona, Italy
3  European Synchrotron Radiation Facility - BP 220, F-38043 Grenoble Cedex, France

(Received 27 April 2004; accepted in final form 7 June 2004)

We report the first observation of an inverted hexagonal phase of phospholipid-DNA-metal complexes. These ternary complexes are formed in a self-assembled manner when water solutions of neutral lipid dioleoylphosphatidylethanolamine (DOPE), DNA and divalent metal cations ( $\chem{Me^{2+}}$; $\chem{Me=Fe}$, $\chem{Co}$, $\chem{Mg}$, $\chem{Mn}$) are mixed, which represents a striking example of supramolecular chemistry. The structure, derived from synchrotron X-ray diffraction, consists of cylindrical DNA strands coated by neutral lipid monolayers and arranged on a two-dimensional hexagonal lattice ( HIIc). Besides the fundamental aspects, DOPE-DNA- $\chem{Me^{2+}}$ complexes may be of great interest as efficient nonviral delivery systems in gene therapy applications because of the low inherent cytotoxicity and the potential high transfection efficiency.

87.14.Cc - Lipids.
87.14.Gg - DNA, RNA.
61.10.-i - X-ray diffraction and scattering.

© EDP Sciences 2004