A New Angle on Pluronic Additives: Advancing Droplets and Understanding in Digital Microfluidics
A New Angle on Pluronic Additives: Advancing Droplets and Understanding in Digital Microfluidics
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DOI：
10.1021/la201185c
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发表时间：
2011-07-05
期刊：
影响因子：
3.9
通讯作者：
Wheeler, Aaron R.
中科院分区：
文献类型：
--
作者：
Au, Sam H.;Kumar, Paresh;Wheeler, Aaron R.
微流控装置中的生物污垢限制了可处理样品的类型和样品可操作的持续时间。尽管处理污染设备的成本很高，但相对较少的策略已经开发出来解决这个问题。在这里，我们分析了八种两亲性液滴添加剂，聚环氧丙烷（PPO）和聚环氧乙烷（PEO）的Pluronic共嵌段聚合物，作为数字微流体中生物堵塞的解决方案，以含血清的细胞培养基作为模型流体。我们的分析表明，具有较长PPO链的物种在使液滴运动和减少生物污染方面具有优势。当以最佳浓度使用时，发现两种测试物种L92和P105相对于以前使用的添加剂可延长设备寿命2-3倍。低PEO含量的Pluronic添加剂（如L92）被发现对永生化哺乳动物细胞系具有细胞毒性，因此我们建议将PEO含量大于或等于50%的Pluronic添加剂（如P105）用于涉及细胞的数字微流体应用。最后，使用接触角测量来探测含pluronic液滴与器件表面之间的相互作用。研究发现，不同类型的接触角测量值与添加剂减少生物污染的能力之间存在很强的相关性，这表明接触角测量值可能是快速筛选具有减少生物污染潜力的新候选材料的有用工具。我们建议，这项研究将对正在开发数字微流控平台的科学家和工程师有用，这些平台可用于涉及含蛋白质溶液的广泛应用，特别是涉及细胞的应用。
Biofouling in microfluidic devices limits the type of samples which can be handled and the duration for which samples can be manipulated. Despite the cost of disposing fouled devices, relatively few strategies have been developed to tackle this problem. Here, we have analyzed a series of eight amphiphilic droplet additives, Pluronic coblock polymers of poly(propylene oxide) (PPO) and poly(ethylene oxide) (PEO), as a solution to biofouling in digital microfluidics using serum-containing cell culture media as a model fluid. Our analysis shows that species with longer PPO chains are superior for enabling droplet motion and reducing biofouling. Two of the tested species, L92 and P105, were found to lengthen device lifetimes by 2-3 times relative to additives used previously when used at optimal concentrations. Pluronics with low PEO content: such as L92 were found to be cytotoxic to an immortalized mammalian cell line, and therefore we recommend that Pluronic additives with greater or equal to 50% PEO composition, such as P105, be used for digital microfluidic applications involving cells. Finally, contact angle measurements were used to probe the interaction between Pluronic-containing droplets and device surfaces. Strong correlations were found between various types of contact angle measurements and the capacity of additives to reduce biofouling, which suggests that contact angle measurements may be useful as a tool for rapidly screening new candidates for the potential to reduce biofouling. We propose that this study will be useful for scientists and engineers who are developing digital microfluidic platforms for a wide range of applications involving protein-containing solutions, and in particular, for applications involving cells.