A High-Throughput Device for Patterned Differentiation of Embryoid Bodies

Although ontogenesis in vivo may proceed in a spatiotemporally heterogeneous environment, in vitro differentiation of an embryoid body (EB) has been carried out in uniform conditions using conventional culture methods at low throughput. In the present study, a microfluidic device with multiple culture chambers for simultaneous patterned differentiation of multiple EBs of pluripotent stem cells is newly developed. Theoretical simulation and experiments using a suspension of fluorescent particles or fluorescent solution show that proper chemical gradients can be formed with almost no flow in the chambers. After multiple EBs are introduced into the device, these EBs move along the flow channel and into trapping cups. The EBs are pushed by air bubbles into the culture chambers. These multiple EBs can be cultured within the culture chambers after flowing culture medium removes the air bubble from the device. In our experiment, differentiation and proliferation of these multiple EBs are studied by exposing them to two different media for 6 days: one to induce differentiation and the other to keep the pluripotent and self-renewing state of the cells. It is shown that patterned differentiation of the multiple EBs is successfully conducted simultaneously in the device when these two media are perfused into the device. The results suggest that differentiation and proliferation of multiple EBs can be analyzed by applying chemical gradients in the present microfluidic device. This will be a helpful tool in a wide variety of experiments involving EBs or spheroids.