Abstract

Jamming state transition has been used in literature to describe migrating-to-resting cell state transition during collective cell migration without proper rheological confirmation. Yield stress often has been used as an indicator of a jamming state. Yield stress points to the liquid-to-solid state transition, but not a priori to jamming state transition. Various solid states such as elastic solid and viscoelastic solids can be considered in the context of their ability to relax. The relaxation time for (1) an elastic solid tends to zero, (2) Kelvin-Voigt viscoelastic solid is finite, and (3) jamming state tends to infinity.In order to clarify the meaning of jamming state from the rheological standpoint we formulated the constitutive model of this state based on following conditions (1) migration of the system constituents is much damped such that the diffusion coefficient tends to zero, (2) relaxation time tends to infinity, (3) storage and loss moduli satisfy the condition G′(ω)/G"(ω) = const > 1. Jamming state represents the non-linear viscoelastic solid state. The main characteristic of this state is that the system cannot relax.Jamming state transition of multicellular systems caused by collective cell migration is discussed on a model system such as cell aggregate rounding after uni-axial compression between parallel plates based on the data from the literature. Cell aggregate rounding occurs via successive relaxation cycles. Every cycle corresponds to a different scenario of cell migration. Three scenarios were established depending on the magnitude of mechanical and biochemical perturbations (1) ordered scenario with reduced perturbations corresponds to the case that most of the cells migrate, (2) disordered scenario corresponds to the case that some cell groups migrate while the others (at the same time) stay in resting state (corresponds to medium perturbations), and (3) highly suppressed cell migration under large perturbations corresponds to the viscoelastic solid under jamming state. If cells reach the jamming state in one cycle, they are able to overcome this undesirable state and start migrating again in the next cycle by achieving the first or second scenarios again.

Highlights

  • Main features of cell rearrangement during collective cell migration related to the viscoelasticity of multicellular surfaces are important for the deeper understanding of various biological processes such as wound healing, tumorigenesis, and morphogenesis [1,2,3,4,5,6]

  • Jamming state satisfies the condition that the relaxation time tends to infinity τR → ∞ as reported by Honter and Weeks [16]

  • The main goal of this theoretical consideration is to (1) describe jamming state from the rheological point of view and (2) consider long-time cell rearrangement caused by collective cell migration based on formulated jamming state transition

Read more

Summary

Introduction

Main features of cell rearrangement during collective cell migration related to the viscoelasticity of multicellular surfaces are important for the deeper understanding of various biological processes such as wound healing, tumorigenesis, and morphogenesis [1,2,3,4,5,6]. Pajic-Lijakovic and Milivojevic Journal of Biological Engineering (2019) 13:73 These transitions have been considered as jamming state transitions [11,12,13,14,15,16]. Garcia et al [11] indicated parameters that influence cell jamming (1) cellular packing density which depends on cell type and growth conditions, (2) cell −cell adhesion energy, (3) magnitude of cellular forces and persistence time for these forces, and (4) cell shape. They pointed out that cell monolayers behave as amorphous solids under reduced cell velocities. Sharp phase transitions didn’t observe, rather a dynamic change in the dominant internal forces that control the motion

Results
Discussion
Conclusion
Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call