New hydrophobic charge-induction resin with 2-mercaptoimidazole as the ligand and its separation characteristics for porcine IgG

Insights into the Understanding of Adsorption Behaviors of Legacy and Emerging Per- and Polyfluoroalkyl Substances (PFASs) on Various Anion-Exchange Resins

Per- and polyfluoroalkyl substances (PFASs) have received extensive attention due to their various harmful effects. In this study, the adsorptive removal of 10 legacy and emerging PFASs by four anion-exchange resins (including gel and macroreticular resins) were systematically investigated. Our results showed that the capacities of resins absorbing PFASs were ranked in the following order: gel strong base HPR4700 (297~300 μg/g) ≈ macroreticular strong base S6368 (294~300 μg/g) ≈ macroreticular weak base A111S (289~300 μg/g) > gel weak base WA10 (233~297 μg/g). Adsorption kinetic results indicated that the adsorption process might involve chemical and Henry regime adsorption or reaction control. Intraparticle diffusion was probably the major removal step. Co-existing fulvic acid (0.5, 1, 5 mg/L) and inorganic anions (5 mg/L of sulfate, carbonate, bicarbonate) would hinder the PFAS removal by resins with WA10 showing the highest inhibition rate of 17% and 71%, respectively. The adsorption capacities of PFBA decreased from 233 μg/g to 194 μg/g, and from 233 μg/g to 67 μg/g in the presence of fulvic acid and inorganic anions, respectively. PFASs were more easily removed by HPR4700, S6368, and A111S under neutral and alkaline environment. Moreover, WA10 was not able to remove PFASs under an alkaline medium. This study offered theoretical support for removing PFASs from aqueous phases with various resins.

Rapid preparation of 1-vinylimidazole based non-affinity polymers for the highly-selective purification of antibodies from multiple biological sources

There is an urgent need for developing advanced purification techniques with the merits of low cost and satisfactory capacity in order to meet the challenges in the current downstream purification of monoclonal antibodies (mAbs). Herein, a simple and inexpensive nitrogen heterocycle molecule, 1-vinylimidazole (VIM), was proposed as the capture ligand of antibodies for the first time. The corresponding VIM-based non-affinity polymeric material (polyVIM) was then fabricated via a one-step polymerization for use in the highly selective purification of antibodies. Compared to the previously reported materials, this novel material exhibited many advantages without clearly sacrificing selectivity, such as a simpler and faster fabrication (within 1.5 h), comparable or even higher binding capacity (saturated static adsorption capacity > 190 mg/g polymer, dynamic binding capacity about 31.62 mg/g polymer), lower non-specific protein adsorption, and much lower cost. Notably, the polyVIM can effectively purify the antibodies from multiple biological sources with high purity (95.4% for mAbs in the cell culture medium, 93.3% for hIgG in the human serum), with an acceptable recovery (91.6% for mAbs, 77.0% for hIgG), and good reusability (> 10 times). Moreover, the target ELISA binding assay and NFAT-luc reporter gene assay demonstrated that the enriched antibodies can well maintain their binding activity and bioactivity during the whole purification process. The excellent performance of the polyVIM material may be attributed to the high recognition ability of VIM for antibodies, as well as the biocompatible and antifouling properties of the porous polymer. This study provides a promising alternative material for the purification of mAbs in downstream processes and the enrichment of hIgG in human serum.