Usta O Berk, Alexeev Alexander, Zhu Guangdong, Balazs Anna C
Chemical Engineering Department, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA.
ACS Nano. 2008 Mar;2(3):471-6. doi: 10.1021/nn700379v.
Using simulation and theory, we demonstrate how nanoparticles can be harnessed to regulate the interaction between two initially stationary microcapsules on a surface and promote the self-propelled motion of these capsules along the substrate. The first microcapsule, the "signaling" capsule, encases nanoparticles, which diffuse from the interior of this carrier and into the surrounding solution; the second capsule is the "target" capsule, which is initially devoid of particles. Nanoparticles released from the signaling capsule modify the underlying substrate and thereby initiate the motion of the target capsule. The latter motion activates hydrodynamic interactions, which trigger the signaling capsule to follow the target. The continued release of the nanoparticles sustains the motion of both capsules. In effect, the system constitutes a synthetic analogue of biological cell signaling and our findings can shed light on fundamental physical forces that control interactions between cells. Our findings can also yield guidelines for manipulating the interactions of synthetic microcapsules in microfluidic devices.
通过模拟和理论，我们展示了如何利用纳米颗粒来调节表面上两个初始静止的微胶囊之间的相互作用，并促进这些胶囊沿基底的自推进运动。第一个微胶囊，即“信号”胶囊，包裹着纳米颗粒，这些纳米颗粒从该载体内部扩散到周围溶液中；第二个胶囊是“目标”胶囊，最初不含颗粒。从信号胶囊释放的纳米颗粒改变了下面的基底，从而启动了目标胶囊的运动。后者的运动激活了流体动力相互作用，触发信号胶囊跟随目标。纳米颗粒的持续释放维持了两个胶囊的运动。实际上，该系统构成了生物细胞信号传导的合成类似物，我们的发现可以揭示控制细胞间相互作用的基本物理力。我们的发现还可以为在微流控设备中操纵合成微胶囊的相互作用提供指导。
