Reconstruction of 3D Hierarchic Micro-Tissues using Monodisperse Collagen Microbeads

We successfully established a three-dimensional (3D) hierarchic cell co-culture system using micro-collagen beads. Our reconstructed tissues have double cell-layers that provide an in vivo-like micro-environment. To prepare the hierarchic tissue structures, we used an axisymmetric flow-focusing device (AFFD) that allows us to encapsulate HepG2 cells within monodisperse collagen beads. We then seeded 3T3 cells on the surface of the collagen beads. We observed that HepG2 cells and 3T3 cells successfully self-organized into hierarchical cell structures of uniform size. We believe the in vitro 3D co-culture beads are useful for the studies of in vivo-like cell-cell interactions with various cells. Moreover, the monodispersity of the 3D cell cultured beads facilitates on-chip assays of chemicals/drugs.