A numerical study on the loading of cryoprotectant cocktails-on-a-chip, Part I: Interacting miscible viscous fluids
A numerical study on the loading of cryoprotectant cocktails-on-a-chip, Part I: Interacting miscible viscous fluids
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DOI：
10.1016/j.ijheatmasstransfer.2014.07.026
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发表时间：
2014-11
影响因子：
5.2
通讯作者：
T. Scherr;Shelby Pursley;W. Monroe;K. Nandakumar
中科院分区：
文献类型：
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作者：
T. Scherr;Shelby Pursley;W. Monroe;K. Nandakumar
微流体装置中的层流已显示出作为冷冻保护剂向生物细胞的有效递送机制的前景。为了使这种方法获得更广泛的应用，其与更现实和更复杂的冷冻保护剂混合物一起使用的潜力需要进一步探索。在这项工作中，我们研究了与由 1.5 M 1,2-丙二醇、1.5 M 二甲基亚砜和纯水组成的冷冻保护剂混合物相关的传输现象。粘性且可混溶的液体通过压力梯度驱动通过 25 厘米长的微通道，入口流量为操作参数。我们的模型解决了空间变化的粘度场、速度场和三种化学物质的浓度。每个入口处的流速相等，形成粘性片并跨越通道的垂直方向。根据在上游入口处引入的冷冻保护剂，粘性片材可以向通道中心移动并被粘性较小的混合物包围。这导致了在横向上具有三个最大值的独特速度分布。随着入口流速降低，可混溶液体有更多的时间进行分子扩散。进一步降低流速会导致三种化学物质充分混合的粘性混合物。这种冷冻保护剂装载配置的特点是独特的，通过额外的优化，可以提高冷冻保存期间的细胞存活率。
The laminar flow in microfluidic devices has shown promise as an effective delivery mechanism for cryoprotective agents to biological cells. For this method to gain more prevalence, its potential for use with more realistic and more complicated mixtures of cryoprotectants requires further exploration. In this work, we investigate the transport phenomena associated with a cryoprotectant cocktail consisting of 1.5 M 1,2-propanediol, 1.5 M dimethyl sulfoxide, and pure water. The viscous and miscible liquids are driven through a 25-cm long microchannel by a pressure gradient with inlet flow rate as the operating parameter. Our model resolves the spatially varying viscosity field, velocity field, and the concentrations of the three chemical species. With equal flow rates at each inlet, viscous sheets are formed and span the vertical direction of the channel. Depending on which cryoprotectant is introduced at the upstream inlets, the viscous sheets can move towards the center of the channel and be surrounding by less the less viscous mixture. This causes a unique velocity profile with three maxima in the transverse direction. As the inlet flow rates are decreased, the miscible liquids are afforded more time for molecular diffusion. Further decreasing the flow rate leads to a well-mixed viscous mixture of the three chemical species. The features of this cryoprotectant loading configuration are unique and, with additional optimization, could lead to improved cell survival rates during cryopreservation.