Alginate Encapsulation of Pluripotent Stem Cells Using a Co-axial Nozzle
Alginate Encapsulation of Pluripotent Stem Cells Using a Co-axial Nozzle
复制标题
DOI：
10.3791/52835
复制
发表时间：
2015-07-01
影响因子：
1.2
通讯作者：
Sakai, Yasuyuki
中科院分区：
文献类型：
--
作者：
Horiguchi, Ikki;Sakai, Yasuyuki
多能干细胞因其在再生医学和药物筛选中的重要作用而成为研究的热点。然而，在这些应用中使用PS细胞需要开发一种大规模培养系统。悬浮培养是一种很有前途的大规模生产PS细胞的培养方法，但在控制细胞聚集和限制培养基的剪切应力等方面还有待解决。为了解决这些问题，我们开发了一种采用同轴喷嘴的海藻酸钙包封方法。该方法可以通过共流N-2气体轻松控制胶囊的大小。可控胶囊直径必须大于500 μ m，因为N-2气体流速过高会导致液滴破裂，导致胶囊尺寸不均匀。此外，低浓度的Alg-Na和CaCl2导致非球形胶囊。虽然没有Alg-PLL涂层的Alg-Ca胶囊很容易溶解，可以收集细胞，但它们也可能从没有Alg-PLL涂层的胶囊中泄漏出来。事实上，藻酸盐-锁相环涂层可以防止细胞泄漏，但也很难打破。由于包封可以改变细胞周围的微环境，包括细胞外基质和分泌因子的浓度，因此该技术可以用于干细胞生态位的研究以及PS细胞的批量生产。
Pluripotent stem cells (PS cells) are the focus of intense research due to their role in regenerative medicine and drug screening. However, the development of a mass culture system would be required for using PS cells in these applications. Suspension culture is one promising culture method for the mass production of PS cells, although some issues such as controlling aggregation and limiting shear stress from the culture medium are still unsolved. In order to solve these problems, we developed a method of calcium alginate (Alg-Ca) encapsulation using a coaxial nozzle. This method can control the size of the capsules easily by co-flowing N-2 gas. The controllable capsule diameter must be larger than 500 mu m because too high a flow rate of N-2 gas causes the breakdown of droplets and thus heterogeneous-sized capsules. Moreover, a low concentration of Alg-Na and CaCl2 causes non-spherical capsules. Although an Alg-Ca capsule without a coating of Alg-PLL easily dissolves enabling the collection of cells, they can also potentially leak out from capsules lacking an Alg-PLL coating. Indeed, an alginate-PLL coating can prevent cellular leakage but is also hard to break. This technology can be used to research the stem cell niche as well as the mass production of PS cells because encapsulation can modify the micro-environment surrounding cells including the extracellular matrix and the concentration of secreted factors.