Designing a Microfluidic Device with Integrated Ratiometric Oxygen Sensors for the Long-Term Control and Monitoring of Chronic and Cyclic Hypoxia.
Designing a Microfluidic Device with Integrated Ratiometric Oxygen Sensors for the Long-Term Control and Monitoring of Chronic and Cyclic Hypoxia.
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DOI：
10.3390/s150820030
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发表时间：
2015-08-14
期刊：
影响因子：
--
通讯作者：
Cheung KC
中科院分区：
文献类型：
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作者：
Grist SM;Schmok JC;Liu MC;Chrostowski L;Cheung KC
体外细胞培养中的氧气控制是一个相当有趣的话题，因为慢性和周期性缺氧可以改变细胞行为。静态和瞬时缺氧水平都被发现会影响肿瘤细胞的行为;在药物筛选的早期、体外阶段包括这些影响可能是有价值的。其包含的障碍是短暂缺氧的速率可以是几个循环/小时，这在传统的体外细胞培养环境中难以再现，因为从对照气体到细胞的扩散距离很长。我们使用一个透气的三层微流体装置，以实现空间和时间的氧气控制与生物相关的切换时间。我们测量的氧分布与集成，比率光学氧传感器，证明传感器和系统的稳定性，在多日的实验，并表征预漂白过程，以提高传感器的稳定性。我们显示，与有限元建模和实验数据，出色的控制氧气水平的设备，独立的流体流速和氧合的操作流态。我们测量大约10分钟的平衡时间，生成复杂的、随时间变化的氧气分布，并研究含氧介质流速对测量的氧气水平的影响。该装置可以成为未来长期研究缺氧条件下细胞行为的有用工具。
Control of oxygen over cell cultures in vitro is a topic of considerable interest, as chronic and cyclic hypoxia can alter cell behaviour. Both static and transient hypoxic levels have been found to affect tumour cell behaviour; it is potentially valuable to include these effects in early, in vitro stages of drug screening. A barrier to their inclusion is that rates of transient hypoxia can be a few cycles/hour, which is difficult to reproduce in traditional in vitro cell culture environments due to long diffusion distances from control gases to the cells. We use a gas-permeable three-layer microfluidic device to achieve spatial and temporal oxygen control with biologically-relevant switching times. We measure the oxygen profiles with integrated, ratiometric optical oxygen sensors, demonstrate sensor and system stability over multi-day experiments, and characterize a pre-bleaching process to improve sensor stability. We show, with both finite-element modelling and experimental data, excellent control over the oxygen levels by the device, independent of fluid flow rate and oxygenation for the operating flow regime. We measure equilibration times of approximately 10 min, generate complex, time-varying oxygen profiles, and study the effects of oxygenated media flow rates on the measured oxygen levels. This device could form a useful tool for future long-term studies of cell behaviour under hypoxia.