HINDERED TRANSMEMBRANE PROTEIN-TRANSPORT IN HOLLOW-FIBER DEVICES

Protein transport in the extracapillary and intracapillary spaces (ECS and ICS) as well as across the membranes of hollow-fibre devices was investigated. Regenerated-cellulose ultrafiltration membrane cartridge s were loaded with solutions of myoglobin and operated in the closed-s hell mode for a period of several days. The transmembrane leakage and spatial distribution of myoglobin were dependent on the protein loadin g, the ICS flow rate and the presence of bovine serum albumin in the E CS. A mathematical model was developed to characterise the time-depend ent protein redistribution, taking into account the effects of osmotic pressure, fibre expansion under wet conditions and the fibre-free man ifold regions of the ECS. According to the model, the transmembrane tr ansport of protein can be described using one semi-empirical parameter , the membrane constant, defined as the ratio of the square of pore to rtuosity to surface porosity, from which the osmotic reflection coeffi cient, the partition coefficient, and the diffusive and convective hin drance factors can be calculated. The experimental data were used to t est the model and to find the values of the membrane constant for the system under consideration. (C) 1998 Elsevier Science B.V. All rights reserved.