Optical selection of stem cells: application to human embryonic germ cells

人类胚胎生殖细胞（EGCs）能够转化为许多不同类型的细胞，包括具有治疗疾病潜力的细胞。由于这个原因，这些细胞在研究界广泛使用是很重要的。然而，获得强大的纯EGCs系的困难已被证明是一个重大障碍。这方面的主要问题是制备EGCs的混合起始样品非常小，并且难以在实验室培养中繁殖精致的EGCs。为了克服这些困难，我们需要一种获得纯EGCs及其前体的方法。目前的方法并不合适。微电子技术为我们提供了能够对电信号进行快速、大规模并行处理的非常小的设备。同样，光电子学为我们提供了能够对光信号进行大规模并行处理的小型设备。近年来，用于制造这些微型电子设备的硅技术已被应用于对极少量流体的操纵和控制。这项技术的美妙之处在于集成单一微结构微芯片的潜力。在南安普顿，我们最近开发了用于在微米级电路周围传输聚合物珠的光学芯片。电路中的光携带着这些珠子，并且可以切换，这样它们就可以在一个方向或另一个方向上传输。这些珠子的速度取决于它们的成分和大小。我们建议以大致相同的方式运输细胞，因此不同的细胞将被光选择性地沿着不同的轨道“推动”。光是实现这一目的的理想选择，特别是因为所使用的波长不会被细胞吸收，因此不会损坏细胞。不同的细胞将通过它们沿轨道运输的速度来识别。因此，我们计划在不需要任何荧光分子标记的情况下识别EGCs——这是纯化这些细胞的简易性的重大改进。一旦我们有了用于实验的纯细胞群，我们就可以发现在生成EGCs时哪些基因被打开或关闭，以及我们需要在实验室培养物中添加哪些因素来保持EGCs的生长。这些进步将使我们能够将我们的细胞系存入英国干细胞银行，以便其他研究人员可以访问它们，并且整个研究界可以在使用干细胞治疗人类疾病方面取得更快的进展。

Human embryonic germ cells (EGCs) are capable of turning into many different types of cell, including ones with the potential to treat disease. For this reason, it is important that these cells are widely available to the research community. However, the difficulty of acquiring robust pure lines of EGCs has proven a significant barrier. The major problems for this are an extremely small mixed starting sample from which EGCs are made and a difficulty of propagating the delicate EGCs in laboratory culture. To overcome these difficulties, we need to a method to acquire pure EGCs and their precurors. Current methods are unsuitable. Microelectronics has provided us with very small scale devices capable of performing rapid, massive parallel processing of electrical signals. Likewise, optoelectronics has provided us with small scale devices capable of performing massive parallel processing of optical signals. The silicon technology that has been developed to create these tiny microelectronic devices, has in recent years, been applied to the manipulation and control of very small quantities of fluids. The beauty of this technology is the potential for an integrated single microstructured microchip. In Southampton we have recently developed optical chips for the transport of polymer beads around micrometer sized circuits. Light in the circuits carries these beads and can be switched so that they can be transported in one direction or the other. The speed of these beads depends upon their composition and size. We propose to transport cells in much the same way, thus different cells will be selectively 'pushed' by the light along the different tracks. Light is ideal for this purpose, especially since the wavelength to be used is not absorbed by the cell and thus will not damage it. The different cells will be identified by how quickly they are transported along the tracks. So we plan to identify EGCs without the need for any labels of fluorescent molecules - a significant improvement in the ease with which these cells can be purified. Once we have a pure population of cells for our experiments, we can discover which genes are switched on and off as EGCs are made and what factors we need to add to our laboratory cultures to keep EGCs growing. These advances will allow us to deposit our cell lines in the UK Stem Cell Bank so that other researchers can access them and the research community as a whole can make faster progress towards using stem cells to treat human disease.