Spatiotemporally controlled delivery of soluble factors for stem cell differentiation.

Despite the fact that cells in vivo are largely affected by the spatial heterogeneity in their surroundings, in vitro experimental procedures for stem cell differentiation have been relying on spatially uniform culture environments so far. Here, we present a method to form spatiotemporally non-uniform culture environments for stem cell differentiation using a membrane-based microfluidic device. By adopting a porous membrane with relatively large pores, patterned delivery of soluble factors is maintained stably over a period of time long enough for cell differentiation. We report that spatial patterns of mouse induced pluripotent stem cells (miPSCs) differentiation can be controlled by the present method. Furthermore, it is shown that the cell fate decision of miPSCs is determined by time-dependent switching of the delivery pattern. The present technique could be of relevance to the detailed analyses of the characteristics of stem cell differentiation in time and space, opening up a new insight into regenerative biology.