Mechanical properties of lipid layers doped with microparticles

• Applicant: Professor Dr. Ivo Buttinoni
• Subject Area: Physical Chemistry of Molecules, Liquids and Interfaces, Biophysical Chemistry ; Biomaterials ; Experimental Condensed Matter Physics
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 529996057

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 contribute with his expertise on the physical chemical behaviour of single lipids and lipid layers. The German PI will bring his expertise in colloid-laden interfaces and interfacial shear rheology.

• DFG Programme: Research Grants
• International Connection: France
• Cooperation Partner: Jean-Paul Chapel