Ahmed Daniel, Baasch Thierry, Blondel Nicolas, Läubli Nino, Dual Jürg, Nelson Bradley J
Institute of Robotics and Intelligent Systems, ETH Zurich, Zurich, CH-8092, Switzerland.
Institute of Mechanical Systems, ETH Zurich, Zurich, CH-8092, Switzerland.
Nat Commun. 2017 Oct 3;8(1):770. doi: 10.1038/s41467-017-00845-5.
Systems capable of precise motion in the vasculature can offer exciting possibilities for applications in targeted therapeutics and non-invasive surgery. So far, the majority of the work analysed propulsion in a two-dimensional setting with limited controllability near boundaries. Here we show bio-inspired rolling motion by introducing superparamagnetic particles in magnetic and acoustic fields, inspired by a neutrophil rolling on a wall. The particles self-assemble due to dipole-dipole interaction in the presence of a rotating magnetic field. The aggregate migrates towards the wall of the channel due to the radiation force of an acoustic field. By combining both fields, we achieved a rolling-type motion along the boundaries. The use of both acoustic and magnetic fields has matured in clinical settings. The combination of both fields is capable of overcoming the limitations encountered by single actuation techniques. We believe our method will have far-reaching implications in targeted therapeutics.Devising effective swimming and propulsion strategies in microenvironments is attractive for drug delivery applications. Here Ahmed et al. demonstrate a micropropulsion strategy in which a combination of magnetic and acoustic fields is used to assemble and propel colloidal particles along channel walls.
能够在脉管系统中进行精确运动的系统为靶向治疗和非侵入性手术的应用提供了令人兴奋的可能性。到目前为止，大多数工作都是在二维环境中分析推进力，在边界附近的可控性有限。在这里，我们受中性粒细胞在壁上滚动的启发，通过在磁场和声场中引入超顺磁性粒子来展示仿生滚动运动。在旋转磁场存在的情况下，粒子由于偶极 - 偶极相互作用而自组装。由于声场的辐射力，聚集体向通道壁迁移。通过结合这两个场，我们实现了沿边界的滚动型运动。声场和磁场在临床环境中的应用已经成熟。两个场的结合能够克服单驱动技术所遇到的局限性。我们相信我们的方法将在靶向治疗中产生深远影响。在微环境中设计有效的游动和推进策略对于药物递送应用具有吸引力。在这里，艾哈迈德等人展示了一种微推进策略，其中磁场和声场的组合用于沿着通道壁组装和推进胶体粒子。
