Structural Transistions in Lipidic Aqueous Dispersions

Seminar by Anan Yaghmur, Faculty of Pharmaceutical Sciences, University of Copenhagen.

Colloidal nanostructural aqueous dispersions that display nanostructures closely related to those observed in biological membranes is receiving much attention in pharmaceutical applications [1]. These investigated aqueous dispersions with well-defined internal structure in the nanoscale (such as cubosomes, hexosomes, and micellar cubosomes) are based on an interesting class of amphiphilic lipids such as monoglycerides and phospholipids.

In the present contribution, we focus on describing (i) the formation of emulsified microemulsions (EMEs: inverted type microemulsion system dispersed in aqueous medium); (ii) the temperature induced direct liposomes-cubosomes transition, and (iii) our recent studies on the effects of solubilizing hydrophobic guest molecules and varying temperature and pressure on both the dispersed and the non-dispersed structures of these lipidic systems [2-5]. We also present our investigations on combining synchrotron small-angle X-ray scattering (SAXS) with a UV light source (in situ SAXS-UV irradiation) for determining the structure response of gold nanoparticles (NPs)-loaded vesicles [6] or with a stopped-flow appartus for monitoring in situ the structural transitions induced by rapidly added calcium ions to negatively charged vesicles [7].

[1] A. Yaghmur, O. Glatter, Adv. Colloid Interface Sci. 147-148 (2009) 333.
[2] L. de Campo, A. Yaghmur, L. Sagalowicz, M. E. Leser, H. Watzke, O. Glatter, Langmuir 20 (2004) 5254.
[3] A. Yaghmur, L. de Campo, L. Sagalowicz, M. E. Leser, O. Glatter, Langmuir 21 (2005) 569.
[4] A. Yaghmur, M. Kriechbaum, H. Amenitsch, M. Steinhart, P. Laggner, M. Rappolt, Langmuir 26 (2010) 1177.
[5] A. Yaghmur, P. Laggner, M. Almgren, and M. Rappolt, PLoS ONE 3 (2008) e3747.
[6] A. Yaghmur, L. Paasonen, M. Yliperttula, A. Urtti, M. Rappolt, J. Phys. Chem. Lett. 1 (2010) 962.
[7] A. Yaghmur, P. Laggner, B. Sartori, and M. Rappolt, PLoS ONE 3 (2008) e2072.