Lipid membranes carrying lipophilic cholesterol-based oligonucleotides--characterization and application on layer-by-layer coated particles.
Cholesterol-based lipophilic oligonucleotides incorporated into lipid membranes were studied using solid-state NMR, differential scanning calorimetry, and fluorescence methods. Lipophilic oligonucleotides can be used to build nanotechnological structures on membrane surfaces, taking advantage of the specific Watson-Crick base pairing. We used a cholesteryl-TEG anchor first described by Pfeiffer and Hook (J. Am. Chem. Soc. 2004, 126, 10224-10225). The cholesterol-based anchor molecules were found to incorporate well into lipid membranes without disturbing the bilayer structure and dynamics. In contrast to cholesterol, which is known to induce significant condensation of the membrane lipids, the cholesteryl-TEG anchor does not display this property. When the cholesteryl-TEG moiety was covalently bound to an oligonucleotide, the resulting lipophilic DNA molecules inserted spontaneously into lipid membranes without altering their structure. The duplex formed by two complementary cholesteryl-TEG oligonucleotides had increased thermodynamic stability compared to the same oligonucleotides without the anchor, both in solution and incorporated into lipid membranes. Since the cholesteryl-TEG anchor lacks the characteristic properties of cholesterol, oligonucleotides modified with this anchor are equally distributed between liquid-disordered and liquid-ordered domains in "raft" forming membranes. As an example of an application of these lipophilic oligonucleotides, cholesteryl-TEG-DNA was incorporated into supported lipid bilayers formed on polyelectrolyte-coated silica microparticles. The modified oligonucleotides were stably inserted into the lipid membrane and retained their recognition properties, therefore enabling further functionalization of the particles.
Bunge
Andreas
A
Institute of Medical Physics and Biophysics, University of Leipzig, Hartelstr. 16-18, D-04107 Leipzig, Germany.
Loew
Martin
M
Pescador
Paula
P
Arbuzova
Anna
A
Brodersen
Nicolai
N
Kang
Jing
J
Dähne
Lars
L
Liebscher
Jürgen
J
Herrmann
Andreas
A
Stengel
Gudrun
G
Huster
Daniel
D
D002152:Calorimetry, Differential Scanning; D002784:Cholesterol / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008563:Membrane Lipids / Q000737:chemistry*; D008856:Microscopy, Fluorescence; D009841:Oligonucleotides / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry; D013816:Thermodynamics
D008563:Membrane Lipids; D009841:Oligonucleotides; C028914:triethylene glycol; D011092:Polyethylene Glycols; D002784:Cholesterol