Oxygen transfer in a diffusion-limited hollow fiber bioartificial liver

A mathematical model was developed to predict oxygen transport in a hollow fiber bioartificial liver device. Model parameters were taken from the Hepa tix ELAD configuration; a blood perfused hollow fiber cartridge with hepato cytes seeded in the extracapillary space. Cellular oxygen uptake is based o n Michaelis-Menten kinetics, and nonlinear oxygen transport in the blood is considered. The effect of modulating three important parameters is investi gated, namely, the Michaelis-Menten constants V-m (volumetric oxygen consum ption of the hepatocytes) and K-m (half-saturation constant), and hollow fi ber oxygen permeability. A computer implementation of the model is used to assess whether a given cell mass could be maintained within such a device. The results suggest that liver cell lines possessing low rates of oxygen co nsumption could be maintained if membranes of sufficiently high oxygen perm eability are used. For primary hepatocytes, which have much higher oxygen d emands, radial transport of oxygen is rate limiting, and the axial-flow hol low fiber cartridge is thus an inappropriate design fur use as a bioartific ial liver with primary hepatocytes.