Thesis (M.Sc.) - Cairo University - Faculty of Pharmacy - Department of Analytical Chemistry

Human serum albumin (HSA, pI 4.7) is one of the most widely used proteins in pharmaceutical field. Here, pH-responsive neutral, cationic and anionic polyacrylamide molecularly imprinted polymers (nMIP, cMIP, and aMIPrespectively) were prepared for separation of recombinant and wild-type HSA using mixture of polymerization initiators. The effect of pH during preparation and adsorption stages at pI(HSA) ± 2.0 on binding capacity and selectivity; in terms of the imprinting factor (IF) was thoroughly investigated. Gel electrophoresis and Bradford assay were used for screening of the integrity of HSA and calculation of the binding capacity, respectively. Size exclusion high-performance liquid chromatography (SE-HPLC) and reversed phase high-performance liquid chromatography (RP-HPLC) were employed for thorough evaluation of the stability of HSA at the studied experimental conditions and for simultaneous determination of HSA and erythropoietin in their mixtures, respectively. Preparation of the cMIP at pH 6.7 and testing at pH 6.7; that allowed protonation of the monomer (pKa ~ 8.42) showed a significant increase in the binding capacity, but the selectivity of the cationic polymer improved when the same cMIP prepared at pH 6.7 and tested at pH 4.7. Results showed also that nMIP were generally superior to cMIP, where nMIP prepared at pH 2.7 and tested at pH 6.7 showed binding characteristics of (430.00 æg g₋₁, IF 42.91).The aMIP exhibited a great diminishin selectivity which made it out of the competition. In agreement with the stability profile of HSA, all adsorption experiments carried out at pH 2.7, regardless of polymer type (neutral or cationic) revealed poor selectivity

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