论文标题
远离嵌入在生长的多细胞球体中的示踪剂颗粒的平衡动力学
Far from equilibrium dynamics of tracer particles embedded in a growing multicellular spheroid
论文作者
论文摘要
通过将惰性示踪剂颗粒（TPS）嵌入生长的多细胞球体中，可以测量癌细胞（CC）上的局部应力。为了使该技术有效，必须阐明TPS对CCS的动力学的未知效应，以确保TPS不会极大地改变CCS上的局部应力。我们使用理论和模拟表明，由CCS的增殖和凋亡引起的自我生成的（活跃的）力驱动TPS的动力学远离平衡。在时间尺度上，TPS比CC的分裂时间少，TPS表现出亚置动力学（均方根位移，$δ_{tp}（t）\ sim t^{β_{tp}} $，带有$β_{tp} <1 $），与玻璃制度相似。令人惊讶的是，在长期限制的情况下，TPS的运动是超扩散的（$δ_{tp}（t）\ sim t^{α_{tp}} $带有$α_{tp}> 2 $），这是由于持久的定向运动而导致的。相比之下，CCS的增殖随机将其运动随机导致$α_{cc} $超过统一的超级产物行为。最重要的是，$α_{cc} $不受TPS的显着影响。我们的预测可以使用\ textIt {In Betro}成像方法进行测试，其中可以跟踪TPS和CC的运动。
By embedding inert tracer particles (TPs) in a growing multicellular spheroid the local stresses on the cancer cells (CCs) can be measured. In order for this technique to be effective the unknown effect of the dynamics of the TPs on the CCs has to be elucidated to ensure that the TPs do not greatly alter the local stresses on the CCs. We show, using theory and simulations, that the self-generated (active) forces arising from proliferation and apoptosis of the CCs drive the dynamics of the TPs far from equilibrium. On time scales less than the division times of the CCs, the TPs exhibit sub-diffusive dynamics (the mean square displacement, $Δ_{TP}(t) \sim t^{β_{TP}}$ with $β_{TP}<1$), similar to glass-forming systems. Surprisingly, in the long-time limit, the motion of the TPs is hyper-diffusive ($Δ_{TP}(t) \sim t^{α_{TP}}$ with $α_{TP}>2$) due to persistent directed motion for long times. In comparison, proliferation of the CCs randomizes their motion leading to superdiffusive behavior with $α_{CC}$ exceeding unity. Most importantly, $α_{CC}$ is not significantly affected by the TPs. Our predictions could be tested using \textit{in vitro} imaging methods where the motion of the TPs and the CCs can be tracked.
