Optimum fiber spacing in a hollow fiber bioreactor.

A high surface area hollow fiber reactor was developed for mammalian cell culture. The reactor employs an interfiber gel matrix of agar or collagen for cell support. A model was developed to predict cell density as a function of fiber spacing. Optimum spacings are calculated for two sizes of Celgard hollow fibers. Ehrlich Ascites Tumor (EAT) cells were grown to an estimated density of 1.1 x 10(8) viable cells/mL in the extracapillary space-corresponding to an overall reactor density of 7 x 10(7) cells/mL. On the basis of available kinetic and diffusivity data, the model predicts that lactate accumulation may limit cell growth in the early stage of medium utilization, while oxygen delivery becomes limiting at later stages.