Many drug delivery systems include block copolymers to increase solubility and bioavailability of the drug by formation of micelle structures with a hydrophobic compartment for the drug. Most of these systems have the undesirable property of associating stronger at elevated temperatures preventing release of drugs at body temperature or by local heating. In this project, electrostatically controlled self-assemblies of block copolymer will be investigated with the aim of contributing to the development of systems that can release drugs at elevated temperatures. The temperature dependence will be investigated for systems with self-assembly achieved by varying different system parameters. Small-angle x-ray scattering (SAXS) is used for gaining new knowledge on the mechanisms and structure on nanometer length scale.

SAXS is the central experimental technique for this project. It is an ideally suited method for obtaining structural information on nano-particles, surfactant and block copolymer micelles. It gives information on shape, size and organization of particles of sizes up to a few hundred nanometers with a resolution of less than a nanometer. Investigations are done at the in-house SAXS facility and light scattering facility at Aarhus University. Additional measurements are performed by dynamic and static light scattering, turbidimetry, refractive index measurements and density measurements which are also available in the group laboratory.

The project is part of large EU project were a drug delivery system for Fabry disease is being developed based on liposomes. The structure and stability of the liposomal drug delivery system is important for further developing the system and is being investigated using small-angle X-ray scattering and dynamic and static light scattering

Lipids often interact with proteins and give new functionality or change their conformation. In this project, we have investigated a group of complexes formed between oleic acid and several different unfolded proteins. Because of the size of the complexes and the lipid component, it is not possible to obtain much structural information from NMR and crystallography but SAXS can give unique information on several important structural features of the complex.

Pmel17 is an important protein in human skin and responsible for pigmentation through amyloid formation. Amyloid formation is often associated with membrane interactions and in the case of Pmel17, certain lysophospholipids seems to be especially important. We are using structural, spectroscopic and calorimetric methods to investigate the interaction between the repeat domain (RPT) derived from Pmel17 and lysophosphatidylglycerol (LPG). With this, we hope to gain basic understanding of the structure and interactions between a functional amyloid forming protein and a relevant lipid. This could potentially also be studied for other cytotoxic amyloid forming systems.