Bio-functionalized nanofibrous membranes as a hybrid platform for selective antibody recognition and capturing

Poly(vinyl alcohol-co-ethylene) (PVA-co-PE) is attractive for a variety of bio-applications due to its intrinsic hydrophilicity and ease of functionalization. The successful preparation of PVA-co-PE nanofibrous membranes and its applications as an ideal matrix for enzyme immobilization and dye/metal affinity purification have been reported. In this study, we specifically focused on versatile surface chemistries to activate PVA-co-PE nanofibers and their subsequent protein ligand couplings for antibody recognition and capturing, where surface activation can afford the largest amount as well as the highest activity of immobilized protein ligand. Protein A/G and immunoglobulin G (IgG) were applied here as a model pair of affinity ligand and antibody target. Disuccinimidyl carbonate (DSC) was found to offer the highest amount of immobilized affinity ligands. However, its high reactivity toward hydroxyl and amine groups from protein molecules may trigger a multi-binding effect of immobilized ligands and subsequently limit the conformation changes of the ligands, eventually leading to a low ligand activity. Among all of the tested agents, glutaraldehyde (GA) was observed to provide the highest antibody binding capacity as a synergetic result of the high ligand activity and the desired amount of attached ligands. Its higher ligand activity can be ascribed to the potential spacer effect of the oligomeric units formed by GA molecules. The excellent selectivity and efficient capturing ability for target antibody, the desired stability and reliable reusability of protein A/G attached GA pre-activated PVA-co-PE nanofibrous membranes were demonstrated through IgG static binding capacity tests and SDS-PAGE analysis. These exciting results indicate the great potential of the bio-functionalized nanofibrous membranes as a hybrid platform for selective antibody recognition and purification.