Experimental and theoretical study of membrane adsorbers for the primary capture of protein manufacturing

Membrane technology plays an important role in bioprocessing, however the use of membrane adsorbers for the primary capture is still not implemented due to the limited binding capacity of membranes with respect to chromatography beads. In this work, affinity membranes endowed with high capacity have been applied to the purification of monoclonal antibodies. To this aim novel membrane matrices have been functionalized with affinity ligands using Protein A as well as synthetic ligands that exhibit affinity for the Fc portion of antibodies. These new affinity membranes have been characterized both in batch and in chromatographic experiments using pure protein solutions and a cell culture supernatant. The effect of operating conditions on process performance have been studied in detail in order to find the optimal conditions for binding and elution steps. A fundamental study of transport and kinetic phenomena involved in the process has been performed. As a result, a rather complete mathematical model for the affinity membrane process has been developed and validated with the data acquired with different promising membrane materials. The model is predictive for all the different stages, adsorption, washing and elution, and it is a useful tool to assess the use of this technology in large scale process.