Department of Materials Engineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Tokyo 113-8656, Japan.
Langmuir. 2012 Jan 31;28(4):2145-50. doi: 10.1021/la2037586. Epub 2011 Dec 22.
To prepare spherical polymer hydrogels, we used a flow-focusing microfluidic channel device for mixing aqueous solutions of two water-soluble polymers. Continuous encapsulation of cells in the hydrogels was also examined. The polymers were bioinspired 2-methacryloyloxyethyl phosphorylcholine polymer bearing phenyl boronic acid groups (PMBV) and poly(vinyl alcohol) (PVA), which spontaneously form a hydrogel in aqueous medium via specific molecular complexation upon mixing, even when they were in cell culture medium. The microfluidic device was prepared with polydimethylsiloxan, and the surface of the channel was treated with fluoroalkyl compound to prevent sticking of the polymers on the surface. The microfluidic channel process could control the diameter of the spherical hydrogels in the range of 30-90 μm and generated highly monodispersed diameter spherical hydrogels. We found that the polymer distribution in the hydrogel was influenced by the PVA concentration and that the hydrogel could be dissociated by the addition of d-sorbitol to the suspension. The single cells could be encapsulated and remain viable in the hydrogels. The localized distribution of polymers in the hydrogel may provide an environment for modulating cell function. It is concluded that the spontaneous hydrogel formation between PMBV and PVA in the flow-focusing microfluidic channel device is applicable for continuous preparation of a spherical hydrogel-encapsulating living cell.
为了制备球形聚合物水凝胶，我们使用了一种流聚焦微流控通道装置来混合两种水溶性聚合物的水溶液。还研究了连续封装细胞在水凝胶中的情况。这两种聚合物是受生物启发的 2-（甲基丙烯酰氧基）乙基磷酰胆碱聚合物，带有苯硼酸基团（PMBV）和聚乙烯醇（PVA），即使在细胞培养液中，它们也会通过混合时的特定分子络合在水介质中自发形成水凝胶。微流控装置是用聚二甲基硅氧烷制备的，通道表面用氟烷基化合物处理，以防止聚合物粘在表面上。微流控通道工艺可以控制球形水凝胶的直径在 30-90μm 范围内，并产生高度单分散的直径球形水凝胶。我们发现聚合物在水凝胶中的分布受 PVA 浓度的影响，并且通过向悬浮液中添加 D-山梨糖醇可以使水凝胶解离。单个细胞可以被封装在水凝胶中并保持存活。聚合物在水凝胶中的局部分布可能为调节细胞功能提供了一种环境。结论是，PMBV 和 PVA 在流聚焦微流控通道装置中的自发水凝胶形成适用于连续制备球形水凝胶包封活细胞。
