Suspension culture of hepatocyte-derived reporter cells in presence of albumin to form stable three-dimensional spheroids.

Several studies in the past have formed 3-dimensional (3D) spheroids of primary hepatocytes in suspension culture. Unfortunately, primary hepatocytes in a suspension environment tend to lose their differentiated function over time, generally due to damage from fluid shear stress and eventual spheroid settling. We have therefore created a novel suspension culture system, by seeding H35 rat hepatoma cells, a hepatocyte-derived cell line, in a 24-well tissue culture polystyrene (TCPS) plate placed atop an orbital shaker to create 3D spheroids. To provide stability to the formed spheroids, we used a long-chain polymer, bovine serum albumin (BSA), dissolved in the cell culture medium and/or coated on TCPS surfaces placed in suspension configurations. Our results demonstrate that BSA coating of culture surfaces resulted in uniform and well-defined spheroids with little spheroid settling or "flattening" of cell colonies in either static or suspension configurations. In BSA-coated suspension systems, spheroid size scaled with the amount of BSA dissolved in culture medium. In static uncoated cultures, the normalized rat albumin production levels were enhanced by addition of BSA within culture medium. Thus, both addition of BSA to culture medium and application of BSA as a surface coating appear to be meaningful avenues for tailoring spheroid morphology and function. This 24-well plate suspension culture system may be a valuable tool for high throughput investigations of liver cell behavior in a stable, uniform, 3D spheroid state.