Properties of amphiphilic oligonucleotide films at the air/water interface and after film transfer

Abstract

Properties of amphiphilic oligonucleotide films at the air/water interface and after film transfer Keller, R.; Kwak, M.; de Vries, J. W.; Sawaryn, C.; Wang, J.; Anaya, M.; Muellen, K.; Butt, H. -J.; Herrmann, A.; Berger, R. Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. b s t r a c tThe self-assembly of amphiphilic hybrid materials containing an oligonucleotide sequence at the air/water interface was investigated by means of pressure-molecular area (˘-A) isotherms. In addition, films were transferred onto solid substrates and imaged using scanning force microscopy. We used oligonucleotide molecules with lipid tails, which consisted of a single stranded oligonucleotide 11mer containing two hydrophobically modified 5-(dodec-1-ynyl)uracil nucleobases (dU11) at the 5 -end of the oligonucleotide sequence. The air/water interface was used as confinement for the self-assembling process of dU11. Scanning force microscopy of films transferred via Langmuir-Blodgett technique revealed mono-, bi-(˘ ≥ 2 mN/m) and multilayer formation (˘ ≥ 30 mN/m). The first layer was 1.6 ± 0.1 nm thick. It was oriented with the hydrophilic oligonucleotide moiety facing the hydrophilic substrate while the hydrophobic alkyl chains faced air. In the second layer the oligonucleotide moiety was found to face the air. The second layer was found to cover up to 95% of the sample area. Our measurements indicated that the rearrangement of the molecules into bi-and multiple bilayers happened already at the air/water interface. Similar results were obtained with a second type of oligonucleotide amphiphile, an oligonucleotide block copolymer, which was composed of an oligonucleotide 11mer covalently attached at the terminus to polypropyleneoxide (PPO).

Functionalization of Fatty Acid Vesicles through Newly Synthesized Bolaamphiphile–DNA Conjugates

“…32 As other DNA amphiphiles, lipid-DNAs selfassemble into micelles in buffer medium 32 or form layered structures at the air/water interface. 31 Two lipid DNA molecules were investigated regarding their incorporation into fatty acid vesicles. The first one was a 20mer DNA sequence with two hydrophobically modified deoxyuridines (dU) placed in the center of the DNA strand (dU20), which forms a hairpin.…”

“…The tethering of nucleic acids onto the negatively charged fatty acid vesicles posed a more complex challenge than the previously derivatized molecules. Indeed, short nucleic acids are relatively well solubilized in an aqueous medium and their amphiphilic derivatives can self-assemble on their own, e.g., into layers at the interface between water and air 31 or into micelles. 32 Furthermore, repulsive electrostatic interactions between the negatively charged vesicle surfaces and the amphiphilic nucleic acids could negatively impact their insertion in the membranes.…”

A hybrid lipid oligonucleotide: a versatile tool for supramolecular chemistry

“…No stable monolayer at the air/water interface was observed probably because of the too short alkyl chains present in the structure of the LON. 15 The LON molecules started to interact at a surface area of 1390 Å 2 per polar head somewhat ten times larger than traditional phospholipids. This phenomenon was ascribed to the much larger ON polar head.…”

Biomimetic surface modification of polyurethane with phospholipids grafted carbon nanotubes

“…It was demonstrated that PU composites exhibited good mechanical strength in small doses of phospholipids . The amphiphilic phospholipids with tails possess surface active properties, which make them trend to adsorption at the interface as surfactants to reduce the interfacial tension of materials . In our previous work, a kind of phospholipid containing double hydrophobic chains and PC polar head group was synthesized and end‐capped to PUs, and it was demonstrated that the double‐chain phospholipids have the tendency to migrate to surface of PU films .…”