SKM 2023 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

BP: Fachverband Biologische Physik

BP 11: Poster Session I

BP 11.32: Poster

Dienstag, 28. März 2023, 12:30–15:30, P1

Spontaneous engulfment of microparticles by giant unilamellar vesicles — •Clément Marque and Antonio Stocco — Institut Charles Sadron, Strasbourg, France

Giant unilamellar vesicles (GUVs) are micrometer sized concentric phospholipid bilayers, containing an aqueous medium and constituting simple and controllable model systems to study interaction mechanisms of cells. Adhesion, membrane tension and bending are involved in the engulfment of microparticles and a balance between these contributions is necessary to observe particle wrapping by a GUV membrane. In this context, we mimic the particle endocytosis process by using two types of (1 - 2 microns diameter) colloids interacting with GUVs: uniform silica microparticles and Janus microparticles, half coated with gold nanoparticles (10 - 100 nm) and fabricated by a bottom-up microfluidic self-assembly approach. For this purpose, we aim at controlling particle engulfment in absence of any applied external force. By tuning only membrane properties, we define the critical parameters to observe spontaneous engulfment of microparticles by GUVs. We focus our attention on membrane tension, membrane spontaneous curvature and lipid composition. Membrane spontaneous curvature is tuned by addition of salt, adsorbing onto the outer bilayer surface. Membrane composition is adjusted, as well, to tune lipid fluidity, and membrane surface charge. Finally, Janus microparticle-vesicle interaction will be investigated in out of equilibrium conditions when microparticles are able to self-propel and impart an effective force on the membrane by light exploiting the photothermal properties of gold nanoparticles.