Department of Micro Engineering, Kyoto University, Kyoto, Japan.
Methods Mol Biol. 2022;2430:105-119. doi: 10.1007/978-1-0716-1983-4_7.
Microtubule (MT)-motor systems show promise as nanoscale actuator platforms for performing molecular manipulations in nanobiotechnology and micro total analysis systems. These systems have been demonstrated to exert a variety of functions, including the concentration, transportation, and detection of molecular cargos. Although gliding direction control of MTs is necessary for these applications, most direction control methods are currently conducted using micro/nanofabricated guiding structures and/or flow, magnetic, and electric field forces. These control methods force all MTs to exhibit identical gliding behaviors and destinations. In this chapter, we describe an active multidirectional control method for MT without guiding tracks. The bottom-up molecular design allowed MTs to be guided in designated directions under an electric field in a microfluidic device. By designing the stiffness and surface charge density of MTs, three types of MT (Stiff-MT, Soft-MT, and Charged soft-MT) with different mechanical and electrical properties are prepared. The gliding directions within an electric field are predicted according to the measured stiffness and electrophoretic mobility. Finally, the Stiff-MTs are separated from Soft-MTs and Charged soft-MTs with a microfluidic sorter.
微管（MT）-马达系统有望成为纳米级执行器平台，用于在纳米生物技术和微全分析系统中进行分子操作。这些系统已经被证明可以发挥多种功能，包括分子货物的浓缩、运输和检测。尽管 MT 的滑动方向控制对于这些应用是必要的，但大多数方向控制方法目前都是使用微/纳米制造的导向结构和/或流、磁场和电场力来进行的。这些控制方法迫使所有 MT 表现出相同的滑动行为和目的地。在本章中，我们描述了一种无需导向轨道的 MT 主动多向控制方法。这种自下而上的分子设计使 MT 能够在微流控装置中的电场中沿着指定的方向被引导。通过设计 MT 的刚度和表面电荷密度，可以制备具有不同力学和电学性能的三种 MT（硬 MT、软 MT 和带电软 MT）。根据测量的刚度和电泳迁移率预测电场内的滑动方向。最后，使用微流控分选器将硬 MT 与软 MT 和带电软 MT 分离。
