Department of Biochemistry, Cellular and Molecular Biology, University of Tennessee , Knoxville, Tennessee 37996, United States.
J Phys Chem B. 2013 Oct 24;117(42):12844-9. doi: 10.1021/jp402024s. Epub 2013 Jul 2.
We present a model of a collection of active and adhesive Brownian particles that are capable of aggregation. Besides the mechanical interaction between particles, a simple active dynamics term (motility) is included to provide an active movement. At a given instant, each particle is either in an active (swim) or unanimated (stop) state, which is controlled by a random process. The model includes important features that are inspired by the phenomenon of biological cell-cell association. One feature is the mean motility that is related to the percentage of the particle being active and the maximum swimming speed. Another feature is the stochastic nature of switching between the swim and stop state. We explored how these key features affect the nucleation dynamics and the stability of the aggregates using simulations. Interestingly, particles can change their collective behavior by solely altering the frequency of switching between the swim and stop state while keeping the mean motility unchanged. These results provide insight into how motor-driven forces can be utilized by active biological systems to modulate the single-to-cluster transition efficiently. A dimensionless parameter is also proposed to measure the overall strength of the nonequilibrium effect on active particles.
我们提出了一个由活跃且可黏附的布朗粒子组成的集合模型，这些粒子能够聚集。除了粒子之间的力学相互作用外，还包含一个简单的主动动力学项（迁移率），以提供主动运动。在给定的瞬间，每个粒子要么处于活跃（游动）状态，要么处于静止（停止）状态，这由随机过程控制。该模型包含了一些受生物细胞间关联现象启发的重要特征。一个特征是与粒子的活跃百分比和最大游动速度相关的平均迁移率。另一个特征是在游动和停止状态之间切换的随机性。我们通过模拟探索了这些关键特征如何影响成核动力学和聚集体的稳定性。有趣的是，粒子可以通过仅改变游动和停止状态之间的切换频率而不改变平均迁移率来改变它们的集体行为。这些结果为了解马达驱动的力如何被主动生物系统用来有效地调节从单个体到聚集体的转变提供了线索。还提出了一个无量纲参数来衡量非平衡效应对主动粒子的整体影响强度。
