磁场或能控制细胞凋亡信号转换

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《自然—材料学》上的一篇文章介绍了在活体实验和试管实验中进行的利用外部磁场实现细胞凋亡信号的转换。这种有选择地控制程序性细胞凋亡的转换的能力或可在癌症疗法中发挥重要作用。

Jinwoo Cheon等人研制出一种附着有抗体的锌离子掺杂纳米粒子，当其磁性被激活时，便能以细胞凋亡受体为目标并促进凋亡信号通路。研究人员发现其中的抗体能与那些在癌细胞中产生高度表达的互补性受体相结合；随后的磁场变换又促使凋亡受体聚集，从而开始产生凋亡。这种磁场控制同样体现在形态学的变化中，一个例子就是脊椎动物体系中活体实验的典型代表——斑马鱼尾部的细胞凋亡。

在更广泛的设定条件下，研究人员注意到，这种利用磁场变换对细胞过程的控制方法也许可以应用于那些以通过表面膜受体的聚集来调节信号通路为基础的细胞功能。

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A magnetic switch for the control of cell death signalling in in vitro and in vivo systems

    Nature Materials
    (2012)
    doi:10.1038/nmat3430

The regulation of cellular activities in a controlled manner is one of the most challenging issues in fields ranging from cell biology to biomedicine1, 2. Nanoparticles have the potential of becoming useful tools for controlling cell signalling pathways in a space and time selective fashion3, 4. Here, we have developed magnetic nanoparticles that turn on apoptosis cell signalling by using a magnetic field in a remote and non-invasive manner. The magnetic switch consists of zinc-doped iron oxide magnetic nanoparticles5 (Zn0.4Fe2.6O4), conjugated with a targeting antibody for death receptor 4 (DR4) of DLD-1 colon cancer cells. The magnetic switch, in its On mode when a magnetic field is applied to aggregate magnetic nanoparticle-bound DR4s, promotes apoptosis signalling pathways. We have also demonstrated that the magnetic switch is operable at the micrometre scale and that it can be applied in an in vivo system where apoptotic morphological changes of zebrafish are successfully induced.