Three-dimensional microfluidic cell culture device that generates chemical and oxygen gradients

Gas gradients (e.g. oxygen and nitric oxide) and chemical gradients (e.g. cytokines) are determinants of biological functions and pathological mechanisms, but these have not been replicated in vitro. We developed a cell culture microfluidic device that comprises three layers (gas channel, fluid, and cell culture layer) and can generate stable chemical and oxygen gradients simultaneously or independently. The simulated chemical and oxygen gradients were compared with actual measurements based on fluorescence and phosphorescence. The chemical gradients were in good agreement, but the calculated oxygen gradients were estimated to be lower than the measured values. Endothelial cell network formation was inhibited according to the gradient of angiogenesis inhibitors, and tumor cells stained with hypoxia-sensitive dyes fluoresced according to the oxygen gradient. This novel device, which generates chemical and gas gradients, can have many potential applications in physiological and pathological models and in drug screening.