Affinity separation of plasma proteins using a newly synthesized methacrylamidoalanine incorporated porous pHEMA membranes

Abstract

In this study, we synthesized a novel adsorbent to obtain high protein-adsorption capacity utilizing 2-methacrylamidoalanine (MAAL) containing membrane. Amino acid-ligand MAAL was synthesized by using methacrylochloride and alanine. Then, poly(2-hydroxyethylmethacrylate-co-2-methacrylamidoalanine) [p(HEMA-co-MAAL)] membranes were prepared by UV-initiated photopolymerization of HEMA and MAAL in the presence of an initiator (azobisisobutyronitrile, AIBN). Synthesized MAAL was characterized by nuclear magnetic resonance spectroscopy. p(HEMA-co-MAAL) membranes were characterized by swelling studies, porosimeter, scanning electron microscopy, Fourier transform-infra red spectroscopy, and elemental analysis. These membranes have macropores in the size range 5–10 μm. Different metal ions including Zn(II), Ni(II), Co(II), and Cu(II) were chelated on these membranes. p(HEMA-co-MAAL) were used in the adsorption of human serum albumin (HSA) from aqueous media containing different amounts of albumin (0.1–5.0 mg L−1) and at different pH values (4.0–8.0). The maximum HSA adsorption was observed at pH 5.0. The nonspecific adsorption of HSA on the pHEMA membranes was negligible 0.9 μg cm−2. MAAL incorporation significantly increased the HSA adsorption (1.76 mg cm−2). The HSA adsorption capacities of the metal-incorporated membranes were greater than that of the p(HEMA-co-MAAL) membranes under the same conditions. Higher HSA adsorption capacity was observed from the human plasma (2.88 mg HSA cm−2).