Preparation of Magnetic Poly(N-Isopropylacrylamide-4-Vinylphenylboronic Acid) Thermosensitive Microcryogel for...

In this study, poly(N-isopropylacrylamide-4-vinylphenylboronic acid) thermosensitive microcryogels with different magnetic amounts were prepared for immunoglobulin G (IgG) purification. After, the prepared magnetic thermosensitive microcryogels were characterized by scanning electron microscopy, Fourier transform infrared attenuated total reflectance spectroscopy, electron spin resonance spectrometer, and optical microscopy. IgG binding capacities were investigated using aqueous IgG solutions prepared at varying concentrations. The maximum IgG binding capacity of poly(N-isopropylacrylamide-4-vinylphenylboronic acid) thermosensitive microcryogels prepared with different magnetic amounts was calculated as 137 mg/g for microcryogels containing 23.0 mg Fe₃O₄, 72.0 mg/g for microcryogels containing 11.5 mg Fe₃O₄, 48.6 mg/g for microcryogels containing 5.62 mg Fe₃O₄, and 39.2 mg/g for microcryogels without Fe₃O₄ at pH 7.4 phosphate solution and 40°C. It was observed that poly(N-isopropylacrylamide-4-vinylphenylboronic acid) thermosensitive microcryogels can be reused ten times. According to the adsorption results, the adsorption of IgG onto the prepared magnetic poly(N-isopropylacrylamide-4-vinylphenylboronic acid) thermosensitive microcryogels fits the Langmuir isotherm model (Q_max: 147 mg/g, R²: 0.9976). After optimizing the experimental conditions, the purity of the eluted IgG was confirmed by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The developed microcryogels combine thermoreactivity with magnetic properties for efficient IgG purification, offering tunable binding capacities using boronic acid-based affinity.