Naslov
Stochastic dynamics of substrate non-uniform stiffness affecting molecular adhesion in cell– substrate interface subjected to tensile loading

Autori
Qi, Chenwei ; Zhang, Juanjuan ; Smith, Ana-Sunčana ; Li, Long

Izvornik
Journal of Applied Physics (0021-8979) 133 (2023), 22; 224702, 19

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Stochastic dynamics

Sažetak
The mechanically heterogeneous extracellular matrix (ECM) or tissues widely exist in biological systems and are capable of significantly regulating directional cell migration. However, prior to whole cell movement, how the cell senses these cues from mechanical heterogeneities of the ECM or substrate remains unclear at the molecular bond level. To address this issue, we theoretically investigate interface adhesion between a non-uniform stiffness substrate and a rigid plate via a series of receptor–ligand bonds subjected to a tensile loading by integrating substrate surface deformation described by continuum mechanics approach into the stochastic events of bond dissociation and association govern by Markov processes. Interestingly, it is found that, during stretching adhesion interface, due to the large collective contact forces near the stiff edge of the adhesion area, the crack first develops at this stiff edge and then grows to another relatively soft adhesion edge until the completed detachment achieved, which is distinct from the cracks growing from both two edges to center of adhesion area in the case of uniformly elastic solid–solid or solid–fluid interface. Moreover, the lifetime of the bond cluster, interface adhesion strength, and the effect of inter-bond distance are examined, respectively. The corresponding mechanism of dependence of the lifetime and adhesion strength on the non-uniform stiffness of the substrate and inter-bond distance is also analyzed. These findings provide a detailed mechanistic understanding of the adhesion interface responding to the mechanical heterogeneities of the substrate at the molecular bond level.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

Napomena
This study is supported by grants from the
National Natural
Science Foundation of China (12072137) and the
Open Fund
of Key Laboratory for Intelligent Nano Materials
and Devices
of the Ministry of Education NJ2020003 (INMD-
2021M03).
J.Z. would like to acknowledge the support by the
Fundamental
Research Funds for the Central Universities (Grant
No.
lzujbky-2022-19).

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