Inert-living matter, when cells and beads play together

Usharani Nagarajan (1) , Grégory Beaune (1) , Andy Lam (1) , David Gonzalez-Rodriguez (2) , Françoise Winnik (1) , Françoise Brochard-Wyart (3, 4, 5, 6)

1 WPI-MANA - International Center for Materials Nanoarchitectonics
2 LCP-A2MC - Laboratoire de Chimie et Physique - Approche Multi-échelle des Milieux Complexes
3 Institut Curie [Paris]
4 PSL - Université Paris Sciences et Lettres
5 SU - Sorbonne Université
6 PCC - Laboratoire Physico-Chimie Curie [Institut Curie]

While both active and granular matter have been extensively studied, here we investigate what happens when we mix the two of them, in a model system combining microparticles and cell assemblies. On a substrate covered with polystyrene or silica microparticles, we notice two regimes in the spreading of a cell aggregate: light particles are pushed by the cells and form a ring, which bonds to the substrate by adhesion forces that oppose spreading, while for heavy particles, the cell monolayer spreads above the particle bed. In both cases, cell activity is transmitted to inert beads, leading to the formation of cell-microparticle aggregates, which flicker and diffuse. We then study the formation and the spreading of hybrid aggregates of microparticles and living cells and observe phase separations and jamming transitions. Our study may have implications on processes such as cancer metastasis and development, and may guide cancer therapies based on inert particles.

Domaines: Matière Molle [cond-mat.soft]

Usharani Nagarajan, Grégory Beaune, Andy Lam, David Gonzalez-Rodriguez, Françoise Winnik, et al.. Inert-living matter, when cells and beads play together. Communications Physics, 2021, 4, pp.2 (2021). ⟨10.1038/s42005-020-00506-y⟩. ⟨hal-03103706⟩