Seminario impartido por Laura Rodríguez Arriaga, del Instituto de Física de la Materia Condensada (IFIMAC), Instituto Nicolás Cabrera (INC), Universidad Autónoma de Madrid
Cells move through complex media to perform vital biological processes, often following environmental cues. Because the cell membrane is sticky, to move on a substrate, cells must exert finite forces to overcome adhesion across the shearing surfaces, although adhesive cell-substrate contacts may reestablish, fully or partially, during cell motion. Despite of their importance and complex nature, the tribological properties of cell membranes remain largely unexplored. In this talk, I will present a minimal cell model to measure and study the tribological properties of cell membranes. The model consists of a vesicle, an aqueous droplet stabilized by an amphiphilic membrane, produced by microfluidics,1 encapsulating a single magnetic microparticle in the core. Rotation of the encapsulated microparticle under external actuation with a rotating magnetic field results in confined flows that drive microparticle sliding on the inner membrane leaflet. These confined flows produce vesicle rotation and, in the proximity of a substrate, vesicle rolling. The rotation frequency of vesicles with solid-like polymer membranes can be finely tuned by the rotation frequency of the encapsulated particle and the particle-to-vesicle size ratio. This fine tuning of the vesicle rotation frequency provides access to diferent friction regimes spanning from contact to lubrication.2 This approach will be extended to study the tribological properties of more complex membrane systems, including fluid-like membranes, phase-separated membranes or even membranes decorated with receptors to bind specific ligands on substrates. 2 L. R. Arriaga, S. S. Datta et al., Small, 2014, 10, 950-956. 3 P. Magrinya, P. Palacios et al., 2024, arXiv:2402.17707.
Ponente del seminario: Laura Rodríguez Arriaga
Fecha del seminario: 09/10/2024 12:00
Lugar del seminario: salón de actos del IQF
