Model-based performance analysis and scale-up of membrane adsorbers with a cassettes format designed for parallel operation

Application of mechanistic modelling in membrane and fiber chromatography for purification of biotherapeutics - A review

Mechanistic modelling is a simulation tool which has been effectively applied in downstream bioprocessing to model resin chromatography. Membrane and fiber chromatography are newer approaches that offer higher rates of mass transfer and consequently higher flow rates and reduced processing times. This review describes the key considerations in the development of mechanistic models for these unit operations. Mass transfer is less complex than in resin columns, but internal housing volumes can make modelling difficult, particularly for laboratory-scale devices. Flow paths are often non-linear and the dead volume is often a larger fraction of the overall volume, which may require more complex hydrodynamic models to capture residence time distributions accurately. In this respect, the combination of computational fluid dynamics with appropriate protein binding models is emerging as an ideal approach.

Computational fluid dynamics simulation and the experimental verification of protein adsorption on a hollow fiber membranes module

Immobilized metal affinity chromatography (IMAC) ensures the specific purification of proteins containing histidine tags through high affinity with transition metal chelators, which has various applications in biological protein separation. Most chromatographic separations currently use a fixed bed. In this form, internal flow pressure drops very sharply, accompanied by uneven solution flow, pore blockages, etc., all of which greatly reduce separation efficiency. Therefore, this study uses hollow fiber membranes (HFMs) with micron-scale inner diameters as a base, thus reducing operating pressure and significantly enhancing mass transmission. Batch adsorption experiments were performed using flat plate membranes to obtain the reaction's thermodynamic and kinetic model parameters for use in a dynamic column breakthrough simulation. The numerical simulation was based on a single HFM model and established a mathematical model for computational fluid dynamics (CFD) in ANSYS Fluent software. Model accuracy was validated by combining the simulation with experiments. The effects of different module and process parameters on the breakthrough curve were investigated by varying parameters such as flow rate, initial feed concentration, and HFM inner diameter. Design parameters and operating conditions contributing to module utilization were subsequently obtained.

Affinity Membranes and Monoliths for Protein Purification

Affinity capture represents an important step in downstream processing of proteins and it is conventionally performed through a chromatographic process. The performance of this step highly depends on the type of matrix employed. In particular, resin beads and convective materials, such as membranes and monoliths, are the commonly available supports. The present work deals with non-competitive binding of bovine serum albumin (BSA) on different chromatographic media functionalized with Cibacron Blue F3GA (CB). The aim is to set up the development of the purification process starting from the lab-scale characterization of a commercially available CB resin, regenerated cellulose membranes and polymeric monoliths, functionalized with CB to identify the best option. The performance of the three different chromatographic media is evaluated in terms of BSA binding capacity and productivity. The experimental investigation shows promising results for regenerated cellulose membranes and monoliths, whose performance are comparable with those of the packed column tested. It was demonstrated that the capacity of convective stationary phases does not depend on flow rate, in the range investigated, and that the productivity that can be achieved with membranes is 10 to 20 times higher depending on the initial BSA concentration value, and with monoliths it is approximately twice that of beads, at the same superficial velocity.