NAMS 2002 Workshop - ICOM 2008

Biomedical and Biotechnology I – 2
Monday July 14, 10:15 AM-10:45 AM, Honolulu/Kahuku
Developments in Membrane Affinity Chromatography for Monoclonal
Antibody Recovery
S. Dimartino, University of Bologna, Bologna, Italy
C. Boi, University of Bologna, Bologna, Italy
G. Sarti (Speaker), University of Bologna, Bologna, Italy, giulio.sarti@unibo.it
The great number of process development for monoclonal antibodies, presently
in development stage, has emphasized the capability limits of the biotech
industry. The recent improvements of cultivation technology, allow also to
achieve high titers of monoclonal antibody in cell supernatants, and the present
bottleneck for MABs’s production is associated to the downstream process
required for product recovery. Bead-based affinity chromatography with Protein A
is widely used in the primary capture stage. Membrane affinity chromatography
has not yet experienced extensive application due to the lower capacity of
membrane supports compared to chromatographic beads, yet it has several
advantages deserving serious attention. This work is focused on the purification
of Immunoglobulin G (IgG) with affinity membranes. A new Protein A affinity
membrane (Sartorius, Göettingen, Germany), as well as affinity membranes
prepared with synthetic ligands have been characterized in detail in batch and
dynamic experiments. The membranes have been analysed by using pure
solutions of polyclonal IgG, to determine their binding capacity, as well as a cell
supernatant containing monoclonal IgG, to investigate their selectivity and
general behavior. The influence of process conditions like flow rate and feed
concentration on adsorption and elution have been studied to obtain indications
for the optimal process conditions. The affinity membrane purification process
was also simulated with a mathematical model which was validated by using the
experimental data obtained. The model can simulate adsorption, washing and
elution steps by taking into account all the relevant transport phenomena.