Defining process design space for monoclonal antibody cell culture.

The concept of design space has been taking root as a foundation of in-process control strategies for biopharmaceutical manufacturing processes. During mapping of the process design space, the multidimensional combination of operational variables is studied to quantify the impact on process performance in terms of productivity and product quality. An efficient methodology to map the design space for a monoclonal antibody cell culture process is described.

Three-dimensional co-culture of hepatocytes and stellate cells.

Hepatocytes self-assemble in culture to form compacted spherical aggregates, or spheroids, that mimic the structure of the liver by forming tight junctions and bile canalicular channels. Hepatocyte spheroids thus resemble the liver to a great extent. However, liver tissue contains other cell types and has bile ducts and sinusoids formed by endothelial cells.

Dexamethasone effects on rat hepatocyte spheroid formation and function.

Hepatocytes cultured on moderately adhesive surfaces or in spinner flasks spontaneously self-assemble into spherical tissue-like aggregates (spheroids). These spheroids have smooth surfaces and tissue-like polarized cell morphology, including bile canalicular-like channels, and maintain high viability and liver-specific functions for extended culture periods. Dexamethasone (DEX), a synthetic glucocorticoid, is known to elicit various responses in gene expression, and is often added to hepatocyte culture medium.

Characterization of a hollow fiber bioartificial liver device.

A three-compartment bioartificial liver (BAL) has been developed for potential treatment of fulminant hepatic failure. It has been shown previously that viability and liver-specific functions were maintained in laboratory-scale bioreactors of such design. In this study, the performance of hepatocytes in a clinical-scale bioartificial liver was verified by sustained specific production rates of albumin and urea, along with oxygen consumption rates for up to 56 h and liver-specific gene expression for up to 72 h.

Structural polarity and functional bile canaliculi in rat hepatocyte spheroids.

Primary hepatocytes self-assemble into spheroids that possess tight junctions and microvilli-lined channels. We hypothesized that polarity develops gradually and that the channels structurally and functionally resemble bile canaliculi. Immunofluorescence labeling of apical and basolateral proteins demonstrated reorganization of the membrane proteins into a polarized distribution during spheroid culture.