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The role of fluctuations and stress on the effective viscosity of cell aggregates
- Source :
- Proceedings of the National Academy of Sciences of the United States of America, Proceedings of the National Academy of Sciences of the United States of America, 2009, 106 (41), pp.17271-5. ⟨10.1073/pnas.0902085106⟩, Proceedings of the National Academy of Sciences of the United States of America, National Academy of Sciences, 2009, 106 (41), pp.17271-5. ⟨10.1073/pnas.0902085106⟩
- Publication Year :
- 2009
- Publisher :
- Proceedings of the National Academy of Sciences, 2009.
-
Abstract
- 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 τ*, the aggregate as a whole flows with an apparent viscosity η*, and at higher stress it is a shear-thinning fluid. An increasing cell–cell tension results in a higher η* (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.
- Subjects :
- MESH: Emulsions
Compressive Strength
Constitutive equation
MESH: Cell Cycle
[SPI.MECA.MEFL] Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph]
01 natural sciences
[SPI.MECA.MEFL]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph]
Surface tension
Mice
MESH: Cell Aggregation
Stress relaxation
MESH: Animals
[PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph]
MESH: Biomechanics
MESH: Cell Size
Cell Aggregation
MESH: Cells
0303 health sciences
MESH: Stress, Mechanical
Multidisciplinary
Viscosity
Cell Cycle
Mechanics
Cell aggregation
Biomechanical Phenomena
Compressive strength
Physical Sciences
Emulsions
[SDV.IB]Life Sciences [q-bio]/Bioengineering
MESH: Cell Line, Tumor
Materials science
Cells
MESH: Viscosity
Nanotechnology
03 medical and health sciences
Cell Line, Tumor
surface tension
0103 physical sciences
cellular Potts model
Animals
[PHYS.MECA.MEFL] Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph]
Elasticity (economics)
010306 general physics
MESH: Mice
Cell Size
030304 developmental biology
[SDV.IB] Life Sciences [q-bio]/Bioengineering
statistical model
Cellular Potts model
MESH: Compressive Strength
Apparent viscosity
Elasticity
MESH: Elasticity
Stress, Mechanical
Subjects
Details
- ISSN :
- 10916490 and 00278424
- Volume :
- 106
- Database :
- OpenAIRE
- Journal :
- Proceedings of the National Academy of Sciences
- Accession number :
- edsair.doi.dedup.....df2d648783c4b18a24af7e65fdf38e57