Cell function is largely controlled by an intricate web of macromolecular interactions called signaling networks. It is known that the type and the intensity of stimulus affect cell behavior. However, the effect of temporal stimulation to cell behavior and how cell distinguishes two stimuli are still not clear. On the other hand, microfluidic enables the delivery of a precise and exact stimulus to the cell due to the laminar flow established inside its micro-channel. The slow stream delivers controllable inputs according to a certain pattern with adjustable amplitude, frequency and phase.
PDMS microfluidics has been produced via photolithography and soft lithography processes. To characterize the microfluidic performance, two experiments has been conducted. First, by comparing the lifetime of Rhodamine 6G in the present of KI, mixing extent between two inputs was observed using Frequency Lifetime Imaging Microscopy (FLIM). Furthermore, the input-output relationship of KI concentration was also drawn to characterize the amplitude, frequency and phase of the stimuli. Second experiment involved the observation of PC 12 cells proliferation and differentiation inside microfluidic.
Our results demonstrate that complete mixing between two inputs has been achieved. Relationship between input-output of KI concentrations has also been demonstrated and cells were successfully cultured. These results lead to the further investigation of how PC 12 cells respond to the temporal stimulation of Nerve and Epidermal Growth Factor. Furthermore, by applying these two hormones with various amplitude, frequency and phase to PC 12 cells, study of how cells distinguish two stimuli can be established.