Nickel-Functionalized Nanoporous Heterostructure Microparticles for Immunoglobulin G Adsorption and Separation with High Efficiency.

Developing advanced affinity adsorbents for immunoglobulin G (IgG) selective separation and purification is vital for clinical diagnosis and therapy. However, high-cost and low-specificity methods hinder high-purity IgG production. This work has fabricated nanoporous heterostructure microparticles by emulsion polymerization of styrene, divinylbenzene, and acrylic acid on the surface of sulfonated polystyrene particles. Following modification with nickel ions, the Ni-functionalized sulfonated poly-(styrene-divinylbenzene)-poly-(acrylic acid) (SPSDVB-PAA-Ni) exhibits dense nanoporous heterostructures and Ni-chelating sites, enabling electrostatic attraction and metal affinity interactions for the adsorption and separation of IgG. The SPSDVB-PAA-Ni affinity adsorbent demonstrates a high adsorption capacity of 192.7 mg·g with rapid equilibration within 30 min, outperforming protein A/G adsorbents. Furthermore, the separation/purification of IgG from human serum samples is successfully achieved with a recovery of 73.7% and a purity of 83.7%. The study presents the SPSDVB-PAA-Ni polymer microparticles as promising adsorbents for selectively separating antibody drugs, suggesting their potential applications in clinical analysis.