ACS Appl Mater Interfaces. 2018 Mar 21;10(11):9235-9246. doi: 10.1021/acsami.7b16916. Epub 2018 Mar 6.
Microfluidic-based cell encapsulation has promising potential in therapeutic applications. It also provides a unique approach for studying cellular dynamics and interactions, though this concept has not yet been fully explored. No in vitro model currently exists that allows us to study the interaction between crypt cells and Peyer's patch immune cells because of the difficulty in recreating, with sufficient control, the two different microenvironments in the intestine in which these cell types belong. However, we demonstrate that a microfluidic technique is able to provide such precise control and that these cells can proliferate inside microgels. Current microfluidic-based cell microencapsulation techniques primarily use fluorinated oils. Herein, we study the feasibility and biocompatibility of different nonfluorinated oils for application in gastrointestinal cell encapsulation and further introduce a model for studying intercellular chemical interactions with this approach. Our results demonstrate that cell viability is more affected by the solidification and purification processes that occur after droplet formation rather than the oil type used for the carrier phase. Specifically, a shorter polymer cross-linking time and consequently lower cell exposure to the harsh environment (e.g., acidic pH) results in a high cell viability of over 90% within the protected microgels. Using nonfluorinated oils, we propose a model system demonstrating the interplay between crypt and Peyer's patch cells using this microfluidic approach to separately encapsulate the cells inside distinct alginate/gelatin microgels, which allow for intercellular chemical communication. We observed that the coculture of crypt cells alongside Peyer's patch immune cells improves the growth of healthy organoids inside these microgels, which contain both differentiated and undifferentiated cells over 21 days of coculture. These results indicate the possibility of using droplet-based microfluidics for culturing organoids to expand their applicability in clinical research.
基于微流控的细胞包封在治疗应用中具有很大的潜力。它还为研究细胞动力学和相互作用提供了一种独特的方法，尽管这一概念尚未得到充分探索。目前还没有体外模型可以研究隐窝细胞和派尔氏斑免疫细胞之间的相互作用，因为难以在足够的控制下重现这些细胞类型所属的肠道中两种不同的微环境。然而，我们证明了微流控技术能够提供这种精确的控制，并且这些细胞可以在微凝胶内增殖。目前基于微流控的细胞微包封技术主要使用含氟油。在此，我们研究了不同非氟油在胃肠道细胞包封中的应用的可行性和生物相容性，并进一步引入了一种用这种方法研究细胞间化学相互作用的模型。我们的结果表明，细胞活力受液滴形成后发生的固化和纯化过程的影响大于载体相所用油的类型。具体而言，较短的聚合物交联时间，以及细胞接触恶劣环境（例如，酸性 pH 值）的时间较短，会导致保存在微凝胶内的细胞活力超过 90%。使用非氟油，我们提出了一个模型系统，使用这种微流控方法分别将细胞包封在不同的藻酸盐/明胶微凝胶内，以演示隐窝和派尔氏斑细胞之间的相互作用，从而允许细胞间的化学通讯。我们观察到，在这些微凝胶中，与派尔氏斑免疫细胞共培养的隐窝细胞可以改善健康类器官的生长，在 21 天的共培养过程中，这些微凝胶内包含分化和未分化的细胞。这些结果表明，基于液滴的微流控技术用于培养类器官的可能性，可以扩大其在临床研究中的应用。
