Abstract
This paper reports on cluster formation of stem cells under co-cultured conditions by using our original device "TASCL" which has an array of tapered holes 300μm in diameter with hydrophilically modified surfaces to prevent cell adhesion. The device can be easily incorporated into conventional cell culture protocols by just placing the device onto an arbitrary culture substrate. By seeding hepatic-differentiated iPS cells and adipose-derived stromal cells onto the device, the cells aggregated in the areas defined by the holes and self-assembled into a cluster in each microwell. The two types of cells distributed homogeneously in a cluster at first. However, in three days, the adipose-derived stromal cells migrated into the center of the cluster and self-organized into a double-layered cluster. We speculate the difference of hypoxia tolerance of each cell type is the mechanism of the self-organization.
