Molecularly imprinted poly(N-isopropylacrylamide) thermosensitive based cryogel for immunoglobulin G purification

It was aimed to prepare immunoglobulin G (IgG) imprinted thermosensitive p(NIPA-MAH)/IgG-MIP monolithic cryogel for IgG purification. NIPA and MAH was selected as functional comonomers in order to synthesis of thermosensitive IgG imprinted polymer. NIPA is a thermo-responsive monomer with a LCST of 32 °C. It has a hydrophobic character above LCST and hydrophilic character below LCST. MAH provides selective binding on/in the IgG imprinted cavities with the advantage of its ionizable groups depending on change of pH value. After characterization studies, IgG binding capacity of the p(NIPA-MAH) cryogel from aqueous solutions was examined in different experimental conditions. Maximum IgG binding capacity was 106.1 mg/g, obtained at pH 7.4 and 40 °C. The p(NIPA-MAH)/IgG-MIP cryogel was reusable at least ten times. Selectivity of the p(NIPA-MAH) cryogel for IgG was investigated and suitability of the imprinted cryogel for IgG purification from human plasma was confirmed. In conclusion, the resultant cryogel having increased porosity along with high mechanical and chemical strength could meet requirements; thereby these properties make the p(NIPA-MAH)/IgG-MIP cryogel suitable gel matrix for IgG purification. The p(NIPA-MAH)/IgG-MIP cryogel serving as a thermosensitive molecularly imprinted polymer offers high potential for selective recognition of IgG via imprinting and controlled binding-elution opportunity by simple thermoresponsive regulation.