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Volume 7, Issue 6, November 2013
Reactive oxygen species (ROS) are known to be a key factor in the development of cancer, and many exogenous sources are supposed to be related to the formation of ROS. In this paper, a microfluidic chip was developed for studying the production of ROS in lung cancer cells under different chemical and physical stimuli. This chip has two unique features: (1) five relative concentrations of 0, 1/8, 1/2, 7/8, and 1 are achieved in the culture regions; (2) a shear stress gradient is produced inside each of the five culture areas. Lung cancer cells were seeded inside this biocompatible chip for investigating their response to different concentrations of H2O2, a chemical stimulus known to increase the production of ROS. Then the effect of shear stress, a physical stimulus, on lung cancer cells was examined, showing that the production of ROS was increased in response to a larger shear stress. Finally, two antioxidants, α-tocopherol and ferulic acid, were used to study their effects on reducing ROS. It was found that high-dose α-tocopherol was not able to effectively eliminate the ROS produced inside cells. This counter effect was not observed in cells cultured in a traditional chamber slide, where no shear stress was present. This result suggests that the current microfluidic chip provides an in vitro platform best mimicking the physiological condition where cells are under circulating conditions.
7(2013); http://dx.doi.org/10.1063/1.4827916View Description Hide Description
Immiscible aqueous phases, formed by dissolving incompatible solutes in water, have been used in green chemical synthesis, molecular extraction and mimicking of cellular cytoplasm. Recently, a microfluidic approach has been introduced to generate all-aqueous emulsions and jets based on these immiscible aqueous phases; due to their biocompatibility, these all-aqueous structures have shown great promises as templates for fabricating biomaterials. The physico-chemical nature of interfaces between two immiscible aqueous phases leads to unique interfacial properties, such as an ultra-low interfacial tension. Strategies to manipulate components and direct their assembly at these interfaces needs to be explored. In this paper, we review progress on the topic over the past few years, with a focus on the fabrication and stabilization of all-aqueous structures in a multiphase microfluidic platform. We also discuss future efforts needed from the perspectives of fluidic physics, materials engineering, and biology for fulfilling potential applications ranging from materials fabrication to biomedical engineering.