The role of fluctuations and stress on the effective viscosity of cell aggregates. - Inserm - Institut national de la santé et de la recherche médicale Accéder directement au contenu
Article Dans Une Revue Proceedings of the National Academy of Sciences of the United States of America Année : 2009

The role of fluctuations and stress on the effective viscosity of cell aggregates.

Résumé

Cell aggregates are a tool for in vitro studies of morphogenesis, cancer invasion, and tissue engineering. They respond to mechanical forces as a complex rather than simple liquid. To change an aggregate's shape, cells have to overcome energy barriers. If cell shape fluctuations are active enough, the aggregate spontaneously relaxes stresses ("fluctuation-induced flow"). If not, changing the aggregate's shape requires a sufficiently large applied stress ("stress-induced flow"). To capture this distinction, we develop a mechanical model of aggregates based on their cellular structure. At stress lower than a characteristic stress tau*, the aggregate as a whole flows with an apparent viscosity eta*, and at higher stress it is a shear-thinning fluid. An increasing cell-cell tension results in a higher eta* (and thus a slower stress relaxation time t(c)). Our constitutive equation fits experiments of aggregate shape relaxation after compression or decompression in which irreversibility can be measured; we find t(c) of the order of 5 h for F9 cell lines. Predictions also match numerical simulations of cell geometry and fluctuations. We discuss the deviations from liquid behavior, the possible overestimation of surface tension in parallel-plate compression measurements, and the role of measurement duration.
Fichier sous embargo
Fichier sous embargo
Fichier sous embargo
Date de visibilité indéterminée
Fichier sous embargo
Date de visibilité indéterminée

Dates et versions

inserm-00524596 , version 1 (08-10-2010)

Identifiants

Citer

Philippe Marmottant, Abbas Mgharbel, Jos Käfer, Benjamin Audren, Jean-Paul Rieu, et al.. The role of fluctuations and stress on the effective viscosity of cell aggregates.. Proceedings of the National Academy of Sciences of the United States of America, 2009, 106 (41), pp.17271-5. ⟨10.1073/pnas.0902085106⟩. ⟨inserm-00524596⟩
291 Consultations
2 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More