Comparison of an animal product free medium and normal growth supplement on the growth and barrier integrity of a human corneal epithelial cell line

With the development of defined media for general and specific use with cell cultures, and concern over the use of human cells and over potential prion infections associated with growth factor extracts such as bovine pituitary extract, an animal product-free medium has become available. The basic keratinocyte defined medium can be used with a choice of animal product-containing or animal product-free supplements. Human corneal epithelia cell lines were cultured in the media with these two types of supplement, and compared in terms of their growth rates, their capacity to form tight barriers, and calcium regulation of the location of a junction-associated protein, zonula occludins-1 (ZO-1). The growth rates were not different in the two media, as long as the recommended coating was applied to the culture flask for the animal product-free medium. The barrier function was equally effective for confluent cultures seeded at the same densities. A calcium concentration of 100 microM or above resulted in ZO-1 localisation at the cell membrane in either medium. Hence, cultures in the media are comparable, when the coating is employed. Further experiments are being conducted to establish the comparability of responses to chronic treatment with surfactants.