Characterization and resolution of evaporation-mediated osmolality shifts that constrain microfluidic cell culture in poly(dimethylsiloxane) devices
Characterization and resolution of evaporation-mediated osmolality shifts that constrain microfluidic cell culture in poly(dimethylsiloxane) devices
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DOI：
10.1021/ac061990v
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发表时间：
2007-02-01
影响因子：
7.4
通讯作者：
Takayama, Shuichi
中科院分区：
文献类型：
--
作者：
Heo, Yun Seok;Cabrera, Lourdes M.;Takayama, Shuichi
当处理亚微升体积的流体时，蒸发是一个关键问题。本文描述了这个问题，因为它适用于在聚二甲基硅氧烷（PDMS）装置的微流控细胞培养，并提供了一个实用的解决方案。在96小时内测量了通过不同厚度（10、1、0.2或0.1 mm）的PDMS膜的蒸发介导的渗透压变化。即使在加湿的细胞培养箱中，通过PDMS的蒸发和培养基渗透压摩尔浓度的相关变化也是显著的，并阻止了小鼠胚胎和人内皮细胞的生长和发育。一个简单的扩散模型，其中测量的PDMS的扩散系数与类似于10（-9）m（2）/s的报告值相匹配，解释了这些蒸发和渗透压变化。为了克服这个问题，开发了PDMS-聚对二甲苯-PDMS混合膜，其极大地抑制蒸发和渗透压变化，但具有与基于变形的微流体致动系统接口所需的薄度和柔性，保持光学显微镜的清晰度，成功地开发了一个将小鼠胚胎在静态条件下培养成胚泡，并在亚微升体积的培养基的动态再循环下培养人内皮细胞。这些见解和方法表明，专门为胚胎和内皮细胞的研究将是普遍有用的理解和克服蒸发相关的影响，在微流控细胞培养。
Evaporation is a critical problem when handling submicroliter volumes of fluids. This paper characterizes this problem as it applies to microfluidic cell culture in poly(dimethylsiloxane) (PDMS) devices and provides a practical solution. Evaporation-mediated osmolality shifts through PDMS membranes with varying thicknesses (10, 1, 0.2, or 0.1 mm) were measured over 96 h. Even in humidified cell culture incubators, evaporation through PDMS and associated shifts in the osmolality of culture media was significant and prevented mouse embryo and human endothelial cell growth and development. A simple diffusion model, where the measured diffusion coefficient for PDMS matches reported values of similar to 10(-9) m(2)/s, accounts for these evaporation and osmolality shifts. To overcome this problem, a PDMS-parylene-PDMS hybrid membrane was developed that greatly suppresses evaporation and osmolality shifts, yet possesses thinness and the flexibility necessary to interface with deformation-based microfluidic actuation systems, maintains the clarity for optical microscopy, and enables the successful development of single-cell mouse embryos into blastocysts under static conditions and culture of human endothelial cells under dynamic recirculation of submicroliter volumes of media. These insights and methods demonstrated specifically for embryo and endothelial cell studies will be generally useful for understanding and overcoming evaporation-associated effects in microfluidic cell cultures.