Université de Fribourg

Synthesis and biophysical characterization of an odd-numbered 1,3-diamidophospholipid

Neuhaus, Frederik ; Mueller, Dennis ; Tanasescu, Radu ; Balog, Sandor ; Takashi Ishikawa ; Brezesinski, Gerald ; Zumbuehl, Andreas

In: Langmuir, 2018, vol. 34, no. 10, p. 3215–3220

Nanomedicine suffers from low drug delivery efficiencies. Mechanoresponsive vesicles could provide an alternative way to release active compounds triggered by the basic physics of the human body. 1,3-Diamidophospholipids with C16 tails proved to be an effective building block for mechanoresponsive vesicles, but their low main phase transition temperature prevents an effective application in...

Université de Fribourg

Against the rules: pressure induced transition from high to reduced order

Neuhaus, Frederik ; Mueller, Dennis ; Tanasescu, Radu ; Stefaniu, Cristina ; Zaffalon, Pierre-Léonard ; Balog, Sandor ; Ishikawa, Takashi ; Reiter, Renate ; Brezesinski, Gerald ; Zumbuehl, Andreas

In: Soft Matter, 2018, vol. 14, no. 19, p. 3978–3986

Envisioning the next generation of drug delivery nanocontainers requires more in- depth information on the fundamental physical forces at play in bilayer membranes. In order to achieve this, we combine chemical synthesis with physical–chemical analytical methods and probe the relationship between a molecular structure and its biophysical properties. With the aim of increasing the number of...

Université de Fribourg

Correlation of surface pressure and hue of planarizable push-pull chromophores at the air/water interface

Neuhaus, Frederik ; Zobi, Fabio ; Brezesinski, Gerald ; Molin, Marta Dal ; Matile, Stefan ; Zumbuehl, Andreas

In: Beilstein Journal of Organic Chemistry, 2017, vol. 13, no. 1, p. 1099–1105

It is currently not possible to directly measure the lateral pressure of a biomembrane. Mechanoresponsive fluorescent probes are an elegant solution to this problem but it requires first the establishment of a direct correlation between the membrane surface pressure and the induced color change of the probe. Here, we analyze planarizable dithienothiophene push–pull probes in a monolayer at...

Université de Fribourg

Vesicle origami: cuboid phospholipid vesicles formed by template‐free self‐assembly

Neuhaus, Frederik ; Mueller, Dennis ; Tanasescu, Radu ; Balog, Sandor ; Ishikawa, Takashi ; Brezesinski, Gerald ; Zumbuehl,  Andreas

In: Angewandte Chemie International Edition, 2017, vol. 56, no. 23, p. 6515–6518

Phospholipid liposomes are archetypical self-assembled structures. To minimize the surface tension, the vesicles typically are spherical. Deciphering the bilayer code, the basic physical interactions between phospholipids would allow these molecules to be utilized as building blocks for novel, non-spherical structures. A 1,2- diamidophospholipid is presented that self-assembles into a cuboid...

Université de Fribourg

Phase behavior of selected artificial lipids

Zumbuehl, Andreas ; Dobner, Bodo ; Brezesinski, Gerald

In: Current Opinion in Colloid & Interface Science, 2014, vol. 19, no. 1, p. 17–24

The flexibility of biomembranes is based on the physical-chemical properties of their main components - glycerophospholipids. The structure of these modular amphiphilic molecules can be modified through organic synthesis making it possible to study specific physical-chemical effects in detail. In particular, the roles of the hydrophobic tails of the phospholipids and their...

Université de Fribourg

Rigid urea and self-healing thiourea ethanolamine monolayers

Stefaniu, Cristina ; Zaffalon, Pierre-Léonard ; Verolet, Alessio Carmine ∥, Quentin ; Fernandez, Samuel ; Wesolowski, Tomasz A. ; Brezesinski, Gerald ; Zumbuehl, Andreas

In: Langmuir, 2015, vol. 31, no. 4, p. 1296–1302

A series of long-tail alkyl ethanolamine analogs containing amide-, urea-, and thiourea moieties was synthesized and the behavior of the corresponding monolayers was assessed on the Langmuir–Pockels trough combined with grazing incidence X-ray diffraction experiments and complemented by computer simulations. All compounds form stable monolayers at the soft air/water interface. The phase...

Université de Fribourg

Monolayer properties of 1,3-diamidophospholipids

Fedotenko, lllya A. ; Stefaniu, Cristina ; Brezesinski, Gerald ; Zumbuehl, Andreas

In: Langmuir, 2013, vol. 29, no. 30, p. 9428–9435

While nature provides an endless variety of phospholipids presenting hydrolyzable ester linkages for the 1,2-positioned hydrocarbon tails, we designed and synthesized 1,3-diamidophospholipids which contain stable fatty acid amides. These new phospholipids form faceted unilamellar vesicles with mechanosensitive properties. Aiming to understand the mechanism responsible for this behavior at a...