Novel hepatocyte culture system developed using microfabrication and collagen/polyethylene glycol microcontact printing

The better understanding of cell biology and cell communication requires novel culture systems that better represent the natural cell environment in tissues and organs. We developed a spherical organoid (spheroid) microarray culture system using a combination of microfabrication and microcontact printing. The system consisted of a chip that had cylindrical cavities of 300 μm diameter at a density of 700 cavities/cm2. The bottom faces of these cavities were defined as two different regions that either supported or inhibited cell adhesion. In the cell adhesion region, the center of the bottom face of a 100 μm diameter in a cavity was modified with collagen (Col), and in the non-adhesion region, the entire region around the cavity, except the Col spots, was modified with polyethylene glycol. Primary hepatocytes spontaneously formed spheroids with a uniform diameter at the center of each cavity on the chip. Hepatocytes forming spheroids had a cuboidal cell shape, similar to hepatocytes in vivo, and stably maintained liver-specific phenotypes, such as liver-enriched transcriptional factors, albumin secretion, urea cycle enzymes, and intercellular adhesion molecules. This novel culture system may be applicable as a cellular platform for fundamental studies in cell biology and tissue engineering applications.