Batch adsorption/desorption for purification of scFv antibodies using nanozeolite microspheres

Abstract

Zeolites are known as good adsorbents with ion exchange capacity because of their unique physiochemical properties. Their capability of metal ion immobilization makes them a good candidate as an alternative to the chromatography resins. In this study, two types of nanozeolite microspheres including ZSM-5 (Si/Al similar to 27) and 13X (Si/Al similar to 1.3) were synthesized. The Ni+2 ions were immobilized on the synthesized zeolites along with a local clinoptilolite (Si/Al similar to 7.53). Batch adsorption/desorption experiments were performed for the purification of the scFv antibodies using these zeolites. All the zeolites showed a high-speed adsorption kinetics with the shortest time for ZSM-5-Ni+2, reaching the maximum adsorption (100%) in less than 3 min in the pHs ranging from 6.5 to 7.5. In addition to the metal affinity, the hydrophobic property showed to be one of the most effective factors on the adsorption of scFvs. As a result, the less hydrophilic zeolite ZSM-5 was found to be the best adsorbent of scFvs. The mixed mode performance of zeolites by the combination of the metal affinity and the cation exchange properties were analyzed. The Ni+2-immobilized natural clinoptilolite was the only one that displayed a mixedmode capability. In the elution step, the Ni+2-immobilized ZSM-5 provided a markedly higher scFv purity (similar to 90%) with an acceptable purification yield (60%) just by the metal affinity mode. Taken all, relatively short desorption times (similar to 10 min) of the scFv antibodies along with the high adsorption/desorption yields make the ZSM-5-Ni+2 as a promising metal affinity chromatography media for the low concentration scFv solutions.