Modeling & Simulation of Affinity Chromatography & Investigation of CaptureSMB

Abstract: Chromatography was first described in the 1903 by a Russian scientist. Later on chromatography was almost forgotten until the 1940s when two British scientist published a study about liquid chromatography. They were later awarded with the Nobel prize in chemistry for their work in chromatography. Chromatography has since then developed a lot and nowadays several different kinds of liquid chromatography are used. Liquid chromatography are foremost used in the biochemistry, biotechnology, medicine and the pharmaceutical industry. This study had focused on affinity chromatography and to be able to simulate affinity chromatography. Affinity chromatography is when a ligand matrix are used as the stationary phase in the columns. This ligand matrix only binds in to a specific protein in this case IgG and lets the rest of the substances pass by. In this way IgG is separated from the other proteins and contaminations. The IgG is then eluted from the column by a change in the pH value. The work was started with some experimental runs and then a model was combined to fit the experimental data. When the model got a moderately fit to the experimental data it was calibrated to get a better fit by the function lsqcurvefit in MATLAB. With the calibration the exact parameters were given for the model. The next part of the study was to investigate the capacity of the protein A columns HiTrap MabSelect Sure and HiTrap MabSelect Prisma A. The capacity of the columns was investigated by some breakthrough experiments and at the same time the breakthrough profiles were investigated. It was seen that HiTrap MabSelect Prisma A had a greater capacity of about 45mg IgG/ml resin than HiTrap MabSelect SuRe. It was also found that with a lower flowrate, a higher slope was achieved for both the columns. The last part in this study was the investigation of CaptureSMB. CaptureSMB is a combination of affinity chromatography and simulated moving bed (SMB). It uses two columns that by shifting valves gives the appearance that the columns shifts places. CaptureSMB has four different steps. The first step is to load the first column and when breakthrough occurs it is loaded on to the second column. The second step is to elute, strip, cip and regenerate the first column while the second column gets filled. The third step is when the first column are regenerated it is placed after the second column to capture when breakthrough occurs on the second column. The fourth and last step is when the second column are eluted, striped, ciped and regenerated while the first column are loaded. The proposed process for affinity chromatography in this study used four versatile valves, two UV sensors, one conductivity sensor, one pH sensor, three pumps, three inlet valves, one injection valve and two columns.