50 years of structural lipid bilayer modelling has led to a detailed knowledge on the structural and mechanical properties of biomimetic membrane models and helped enormously our understanding of cell life and has led to a vast amount of ground-breaking applications in for instance advanced drug delivery and bioenergy solutions. At the same time, great progress has been achieved on membrane hydration (including the research on hydration forces and simulation studies), however, our picture of nano-confined water in lipid self-assemblies is still far from being complete.
This PhD studentship aims to address this gap and investigates the interplay between lipid membranes and confined water in minute detail, and hereby, considering the structural worlds of lipid aggregates and confined water as an inseparable unit. This holistic approach will help solving open fundamental questions on hydration and structure to function relationship in biointerfaces. Hereby, we will focus on various unsolved aspects of interfacial water by characterizing physical and dynamical properties of lyotropic, biomimetic model membranes with experimental and theoretical methods. A novel aspect of the project is to consider biointerfaces under extreme conditions, both physical and chemical, which are known to result in significant perturbation to water properties.
This project aims to initiate a new chapter in lipid membrane research. Providing a fundamentally new, universal approach on characterizing the molecular structure of biomimetic membranes. This includes determining the nanostructure of lipid self-assemblies in parallel to the co-involved confined water structure. This Bragg PhD studentship will specifically focus on the interplay of lipid-self assemblies and water under full to low hydration and sub-zero environmental conditions.
Since the early years of the first bilayer models of Gorter and Grendel in 1925, biomembrane-research has come a long way. Both, our experimental techniques at hand as well as our biophysical knowledge has improved manifold. We recognise now that biomembranes come in many shapes and with a broad range of compositional variation. Depending on their functional purpose, biointerfaces are flat and have saddle-like shape or display curved tubular and spherical micellar aggregation forms. Moreover, life has to withstand a broad range of extreme environmental settings, such as high pressures of the deep sea, dry desert conditions and a broad range of temperatures. Extreme environments place severe physiochemical constraints on life, altering osmotic pressure, internal dynamics and macromolecular interactions. Such extreme conditions result in significant perturbations to water structure.
This PhD studentship aims to determine the structure and dynamics of model membrane systems mimicking these biointerfaces. In particular, we will focus on the confined water of these lipid/water systems in great detail, and hereby shedding light on its interaction with the lipid matrix. Clarifying how confined water behaves under well-defined extreme conditions, e.g., from full hydration to low relative humidity or sub-zero temperatures, as well as investigating how the structure of water differs under the influence of different types of confinement (planar, tubular, spherical and saddle-like landscapes), will be key to this project. Finally, the influence of compatible solutes which are known to be critical for life in extreme environments, shedding light on the interfacial structure to function relationship of these solutes in well-defined confined spaces.