Temperature-responsive membrane for hydrophobic interaction based chromatographic separation of proteins in bind-and-elute mode

Butyl-acrylate (BA) containing branched poly-(N-isopropyl acrylamide) or PNIPAM copolymer was grafted on filter paper to prepare composite membrane for carrying out temperature-responsive hydrophobic interaction membrane chromatography (HIMC) of proteins. The copolymer demonstrated two-step phase transition behavior due to the presence of BA and PNIPAM, making the changeover from hydrophilic to hydrophobic state more tunable. The feasibility of using the temperature-responsive membrane was demonstrated by controlling human immunoglobulin G (hIgG) binding and release using temperature change. Higher temperature promoted protein binding and lower temperature favored protein release in this process, which was carried out using lyotropic salt-free mobile phase. The purification of monoclonal antibody (mAb) hIgG1-CD4 from simulated CHO cell culture supernatant was carried out to demonstrate practical application for the novel temperature-responsive membrane.