Requirements for brain cell attachment, survival and growth in serum-free medium: effects of extracellular matrix, epidermal growth factor and fibroblast growth factor.

Prolonged survival of dissociated brain cells in serum-free medium has required an incubation in medium containing serum prior to their transfer to serum-free medium. The aim of this study was to eliminate this serum requirement by finding an appropriate substratum for cell survival in a totally serum-free system. Several purified glycoproteins of the extracellular matrix (ECM) and a basal lamina-like ECM produced by corneal endothelial cells were tested for their effect on brain cell attachment and survival. Dissociated brain cells, which had not been exposed to serum, attached well to tissue culture plastic and to the complex ECM (97-98%). Attachment was slightly reduced on fibronectin and type-IV-collagen (90-92%) and inhibited considerably by laminin, type-I-collagen and a surface which had been exposed to serum-containing medium. In each instance, attachment was reduced when cells were seeded in medium containing 2.5% fetal calf serum. The only culture substratum tested which promoted the survival of a mixed population of cells, in the absence of a serum preincubation, was the basal lamina-like ECM. The effect of epidermal growth factor and fibroblast growth factor on cell survival in a serum-free system was investigated. Each hormone stimulated the survival and proliferation of a population of cells which presumably had the appropriate receptors. The relationship between the growth factors and ECM is discussed.