Use of bioactive polymers to regulate differentiation of embryonic stem cells in three-dimensional bioreactors

从非常早期的胚胎中分离出来的人类胚胎干细胞（hES）能够成为体内的任何细胞，并且具有治疗许多严重疾病的巨大潜力。然而，在产生足够数量的he细胞来治疗人类疾病（如心脏病和癌症）方面存在一个实际问题。目前，he细胞必须在专门的条件下以二维（2-D）培养方式生长。这严重限制了可以获得的细胞数量，我们的项目将允许在三维（3-D）中培养he细胞。为了让你体会到he细胞的二维和三维生长的重要性，想象一下你能挤进起居室的网球比你只能放在地板上的网球多多少个。房间的体积越大，你能放进去的网球就越多，而不考虑地板的面积。因此，he细胞的3-D生长使我们能够培养出比目前更多的细胞。然而，这并不容易！如果我们以3d的方式培养he细胞，它们要么死亡，要么变成其他类型的细胞（称为分化），因此我们需要阻止它们分化。我们将使用两种方法在三维培养中阻止hES细胞分化。首先我们用糖。它们与你在咖啡中加入的糖不同，因为它们由一条长链组成，其中包含可以调节生物活动的区域。你体内的所有细胞都含有这些糖，它们对维持细胞的健康和活力非常重要。基本上，我们将使用这些糖来帮助在3d培养中保持he细胞的良好状态。我们将开发的另一种方法使用寡肽。你体内所有的蛋白质都是由氨基酸组成的，而寡肽就是一条氨基酸链。像糖一样，多肽可以调节你体内发生的事情。我们将使用寡肽使hES细胞健康，并允许它们在三维培养中生长。糖和寡肽可以很好地结合在一起，我们希望通过将它们结合在一起，我们可以使he细胞在3-D中生长得很好。通过这种方式，我们将设计出三维的细胞生物反应器，可以产生大量的he细胞。这将使我们能够提供一种大规模生产hES细胞的新技术，然后将它们转化为特定的细胞类型，可能有助于治疗患有严重疾病的患者。

Human embryonic stem (hES) cells, isolated from very early stage embryos, are able to become any cell in the body and have great potential for the treatment of many serious diseases. However there is a practical problem in producing a sufficient number of hES cells to treat human diseases, such as heart disease and cancer. At present hES cells must be grown under specialised conditions as a 2-dimensional (2-D) culture. This severely limits the number of cells that can be obtained and our project will allow the culture of hES cells in 3-dimensions (3-D). To allow you to appreciate the significance of 2-D and 3-D growth of hES cells, imagine how many more tennis balls you could squeeze into your living room compared to those you could only place on the floor. The bigger the volume of the room the more tennis balls you can fit in, irrespective of the area of the floor. Therefore, 3-D growth of hES cells allows us to grow a lot more cells than we can at the present time. However, it's not that easy! If we grow hES cells in 3-D they will either die or turn into other cell types (called differentiation) therefore we need to stop them from differentiating. We will use two methods to stop the hES cells differentiating in 3-D culture. First we will use sugars. These are different to the sugar you put in your coffee since they consist of a long chain containing areas that can regulate biological activities. All the cells in your body naturally contain these sugars and they are very important in maintaining healthy and viable cells. Basically, we will use these sugars to help keep the hES cells feeling well in 3-D culture. The other method we will develop uses oligopeptides. All proteins in your body are made up of amino acids and an oligopeptide is simply a chain of amino acids. Like sugars, peptides can regulate what happens in your body. We will use oligopeptides that make hES cells healthy and allow them to grow in 3-D culture. Sugars and oligopeptides can work well together and we hope that by combining them together we can make the hES cells grow very well in 3-D. In this way we will engineer bioreactors of cells in 3-dimensions that can produce large numbers of hES cells. This will allow us to provide a new technology for mass production of hES cells and then turn them into specific cell types that may help to treat patients with serious diseases.