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

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