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Nanoscale Structure and Dynamics in Biomimetic Lipid Membranes 

Biological functions of cell membranes are controlled by the dynamic organization of lipids and proteins. Our group uses simple membrane mimics in the form of model lipid bilayers to meaningfully explore the interplay between membrane composition, structure, and dynamics and understand resultant membrane functions. Using a suite of techniques, including x-ray/neutron scattering and MD simulations, the aim of this project is to understand: 

  • the effect of lipid diversity and membrane inclusions on nanoscale membrane structure and dynamics
  • the effect of composition on membrane mechanics and associated bending and thickness fluctuations
  • the effect of membrane fluctuations on membrane-protein interactions
  • the role of fast membrane dynamics in biological functions
Nanoscale Structure and Dynamics in Biomimetic Lipid Membranes
Nanoscale Structure and Dynamics in Biomimetic Lipid Membranes

Topographically Nanostructured Lipid Membranes

Lipid bilayers undergo dynamic morphological changes during cellular processes. Despite evidence that membrane reshaping induces compositional rearrangements and functional lipid domains, a clear understanding of topographically-induced membrane reorganization is still lacking. To address this problem, we utilize tunable nanopatterned thermoresponsive polymer scaffolds for topographic control of lipid membranes. This system allows real-time observations of lateral membrane organization and protein-membrane interactions in response to membrane topography and provides insights into critical membrane functions such as signal transduction, cell trafficking, and host-pathogen interactions. It also offers a promising route to thermally switchable membrane-based biosensors. Using a combination of experiment and simulations, the aim of this project is to understand:   

  • how imposed curvature dictates lateral domain formation, stabilization, and localization

  • how lipid diffusion is affected by membrane topography

  • how dynamic changes in scaffold topography influence membrane reshaping

  • how peripheral protein binding responds to local changes in membrane curvature
Topographically Nanostructured Lipid Membranes

Structural and Dynamical Hierarchy in Polymer Nanocomposites 

Polymer nanocomposites (PNCs) are promising candidates for advanced multifunctional light-weight materials. The premise of PNCs lies in the myriad of possibilities they offer in synergistically integrating particle and polymer properties to obtain substantially improved material performance. Although earlier research on nanocomposites has remarkably enhanced our understanding of PNCs, less explored phenomena such as individual and collective chain dynamics and thermodynamically-driven wetting and dispersion phenomena, currently pose significant challenges to the applicability of PNCs in next-generation technologies. The focus of this project is to combine x-ray/neutron scattering with spectroscopy and simulations to understand the hierarchy of structures and dynamics in PNCs, which will guide the design of advanced nanocomposites with controllable material properties.

 

Structural and Dynamical Hierarchy in Polymer Nanocomposites