Nano- and Janus particles interacting with membranes

Nano-objects have a peculiar affinity for cell membranes, and sometimes are able to translocate through it. Their small dimensions, which, in many cases, are of the order of the membrane barrier thickness, but also other factors such as the hydrophobic-hydrophilic balance, are expected to control the interactions. We pursue efforts to understand the fundamental mechanisms of membrane nanoparticle interactions along three routes: i) we develop fast new methods for optical and cryo-TEM (with the EM platform) ii) we finely tune the composition of the lipid membranes, by adding charges, cholesterol or negative curvature lipids, thus approaching compositions of relevant living systems or formulations and iii) we screen different nano-objects (silica, polystyrene, silver, gold and other nanoparticles, cell penetrating peptides with different cargos, cyclodextrins …) in order to explore the relevant parameter space.
See the article: Tear of lipid membranes by nanoparticles.
A new activity has also started on the interactions between bare and Janus colloidal particles and GUVs. Adhesion and membrane wrapping on the particles is predicted to depend not only on the adhesion strength and the bending of the membrane but also on the spontaneous membrane curvature, which describes the asymmetry between the two leaflets of the lipid bilayer. We are investigating by optical microscopy and optical tweezers the interaction of several bare and Janus colloids (silica, PS, platinum, gold etc ) with GUVs made of different lipids in order to understand and control the engulfment of particles by membranes and vesicles.
See the article: Driven Engulfment of Janus Particles by Giant Vesicles in and out of Thermal Equilibrium.