Department of Biomedical Engineering, University of Wisconsin - Madison, WI, USA.
Integr Biol (Camb). 2009 Feb;1(2):182-95. doi: 10.1039/b814565b. Epub 2009 Jan 8.
Microfluidic devices for cell culture based assays provide new types of engineered microenvironments and new methods for controlling and quantifying cellular responses to these microenvironments. However, without an understanding of the effects of the microenvironments present in microdevices from a cellular perspective, it will be challenging to integrate work done in microdevices with biological data obtained via traditional methods. With the adaptation and validation of In Cell Westerns (ICWs) and in situ analysis techniques to microfluidic devices, we can begin to look at a variety of cellular responses to microcultures. Here we observe several differences in proliferation, glucose metabolism, signaling pathway activation and protein expression levels between cells cultured in traditional macroscale cultures and in microfluidic cultures. The issues of glucose starvation, growth factor restriction, volume density and effects of interactions with poly(dimethylsiloxane) (PDMS) were examined to determine the relative importance of each to cell behavior. Changes in glucose metabolism, insensitivity to volume density or media supplementation, and finally reduced proliferation as the exposure to PDMS increased, suggests that perhaps interactions between media/cells and this commonly employed polymer may be significant for some cell based assays. The differences between cells in macroscale and microfluidic cultures suggest that the cellular baseline may be substantially altered in microcultures due to both inherent differences in scale as well as material differences. The observations highlight the need to biologically validate micofluidic devices for cell based assays in order to accurately interpret the data obtained with them in the context of traditional macroculture data. Additional areas of study that will further characterize and validate microscale culture are discussed.
基于细胞培养的微流控装置为细胞提供了新型的工程微环境，并提供了控制和量化细胞对这些微环境响应的新方法。然而，如果不从细胞角度了解微器件中存在的微环境的影响，那么将微器件中的工作与通过传统方法获得的生物学数据进行整合将具有挑战性。通过对微流控装置进行 In Cell Westerns（ICWs）和原位分析技术的调整和验证，我们可以开始观察到各种细胞对微培养的反应。在这里，我们观察到细胞在传统的宏观培养和微流控培养中的增殖、葡萄糖代谢、信号通路激活和蛋白表达水平存在几种差异。研究了葡萄糖饥饿、生长因子限制、体积密度以及与聚二甲基硅氧烷（PDMS）相互作用的影响，以确定每个因素对细胞行为的相对重要性。葡萄糖代谢的变化、对体积密度或培养基补充的不敏感性，以及随着 PDMS 暴露量增加而导致增殖减少，这表明细胞与培养基之间的相互作用以及这种常用聚合物可能对某些基于细胞的测定非常重要。宏观培养和微流控培养中细胞之间的差异表明，由于固有尺度差异以及材料差异，微培养中的细胞基线可能会发生实质性改变。这些观察结果强调了需要对基于细胞的微流控装置进行生物学验证，以便能够根据传统的宏观培养数据准确地解释从这些装置中获得的数据。还讨论了进一步描述和验证微尺度培养的其他研究领域。
