生物谷报道：通常，研究人员都是用药物、化学试剂来控制细胞信号途径的。但是现在，研究人员能够用磁场来控制细胞信号途径。
来自美国波士顿儿童医院的研究人员开发出一种新的纳米生物技术，该技术能够利用磁场在细胞水平上控制信号途径。这项研究的结果发表在1月的《自然·纳米技术》杂志上。
波士顿儿童医院的Don Ingber博士和Robert Mannix博士与哈佛大学的Mara Prentiss博士合作设计出了一种能够使直径30纳米的微珠与细胞表面的受体分子相结合。
Don Ingber博士
当处于磁场中时，这些珠子就变成了磁铁并通过磁力相互吸引。这种吸引力拽着细胞的受体形成一大簇——这种情况就类似药物或其他分子与之结合时的发生的情况一样。进而，这种“簇化”活化了这种受体，从而启动影响不同细胞功能的生物化学信号级联。
(在左图中，细胞已用微磁珠进行预包被，每一个都结合到细胞受体上（见箭头）。当应用磁场时（右图），磁珠变成磁体并聚拢在一起，同时将受体拉近。这个聚拢的过程类似于药物或其它结合到细胞的小分子所起的作用，因此会在细胞中引发相同的生物化学反应。图片由Ingber博士提供。)
生物谷推荐原始出处：
Nature Nanotechnology 3, 36 - 40 (2008)
Published online: 23 December 2007 | doi:10.1038/nnano.2007.418
Subject Categories: Nanobiotechnology | Nanomagnetism and spintronics
Nanomagnetic actuation of receptor-mediated signal transduction
Robert J. Mannix1,4, Sanjay Kumar1,2,4, Flávia Cassiola1, Martín Montoya-Zavala1, Efraim Feinstein3, Mara Prentiss3 & Donald E. Ingber1
Abstract
Complex cell behaviours are triggered by chemical ligands that bind to membrane receptors and alter intracellular signal transduction. However, future biosensors, medical devices and other microtechnologies that incorporate living cells as system components will require actuation mechanisms that are much more rapid, robust, non-invasive and easily integrated with solid-state interfaces. Here we describe a magnetic nanotechnology that activates a biochemical signalling mechanism normally switched on by binding of multivalent chemical ligands. Superparamagnetic 30-nm beads, coated with monovalent ligands and bound to transmembrane receptors, magnetize when exposed to magnetic fields, and aggregate owing to bead–bead attraction in the plane of the membrane. Associated clustering of the bound receptors acts as a nanomagnetic cellular switch that directly transduces magnetic inputs into physiological cellular outputs, with rapid system responsiveness and non-invasive dynamic control. This technique may represent a new actuator mechanism for cell-based microtechnologies and man–machine interfaces.
