The long term goal of this project is to design a serum free chemically defined media (CDM) for optimum growth of mammalian cells, in vitro. Lipids play a critical role in the growth and normal development of cells. However, they are insoluble and have been introduced in media either in complex with carrier protein, or in unstable inclusions known as liposome, rendering the media undefined. During phase I, lipids were conjugated to dextran and were found to be soluble, stable and chemically defined. The conjugates exhibited biological activity and stimulated proliferation, attachment and collagen expression in COLO 357, a human pancreatic cell line, in CDM. In phase II, lipid dextran conjugates will be synthesized in pilot scale, and their effects on proliferation, attachment and product expression will be evaluated in Chinese Hamster Ovary Cells, Bovine Kidney, Vero and mouse SP-2 hybridoma cells. Growth will be monitored microscopically, and by 3H-thymidine uptake assays. 3H-Leucine will be used to quantitate protein synthesis. Antibody production and viral replication will be quantitated by ELISA. A chromogenic assay will be used to assess levels of tissue plasminogen activator A serum free CDM will substantially simplify the isolation and purification of mammalian cell products in culture.
