(97c) Microfluidic Modulation of Neural Differentiation of 3D Stem Cell Aggregates

Embryonic stem cells (ESCs) can be differentiated as aggregates into specific cell and tissue types for a range of applications. However, current studies are limited by culture methods—in particular, the ability to control and perturb the culture environment and to image and assess samples throughout culture. To address these challenges, we developed a microfluidic platform that provides a controlled environment for culture and differentiation of mouse embryonic stem cell (mESC) aggregates. This platform allows us to image samples in situ, track samples longitudinally, and control the rate of media exchange. Microfluidic media exchange can be used to alter concentrations of cell-secreted factors in the local culture environment. Our goal was to assess how the residence time of media components and cell-secreted factors affect cell growth and differentiation to neural cell types.

Results showed that continuous media exchange was detrimental to generation of progenitor motor neurons, potentially because necessary cell-secreted factors were continuously removed. In contrast, exchanging media at defined intervals increased generation of progenitor motor neurons in microfluidic cultures. Interestingly, we also observed asymmetric patterns of differentiation in a subset of cell aggregates: portions of aggregates better protected from flow were observed to have increased numbers of motor neuron progenitors. Together, our results provide insight into how microfluidic media exchange can modulate cell behavior and differentiation. This can inform design of microfluidic culture conditions in future studies of directed differentiation and tissue morphogenesis.