MechAnical prOPerties of Lipid Layers dOped with microparticles – Appollo

Lipid monolayers such as lung surfactants or the outer layer of the tear film control crucial organ activities. Even though they are frequently exposed to micropollutants, the fundamental mechanism behind the adsorption of microparticles at lipid laden interfaces and its effect on the macroscopic mechanical properties of the lipids remain fairly unexplored problems.

In this collaborative project, we will explore (1) how solid microparticles adsorb and self-assemble at flat lipid-laden interfaces, (2) how they move thereat, and (3) how their presence affects the overall rheological properties of the lipid monolayers. We will combine microparticles with different shapes and surface properties with lipid monolayers exhibiting liquid-like and solid-like, and study them in a Langmuir-Blodgett trough (LT). We will use in-situ and ex-situ techniques to elucidate how the colloidal particles adsorb and self-assemble at the monolayer. Once adsorbed, we will observe their 2D dynamics and link it to local microstructure of the lipids. Finally, we will measure the rheological response of lipid layers with increasing number of absorbed particles by coupling the LT with an interfacial shear rheometer.

The project will shed light on the interaction between lipid membranes and microparticles, and its macroscopic mechanical consequences. The complementary knowledge of the scientific partners is crucial for the success of the project. The French PI will bring his expertise on the physico-chemical behavior of single lipids and lipid layers and their processing at a liquid-liquid/solid interface. The German PI will bring his expertise in colloid-laden interfaces and interfacial shear rheology.