New metal chelate sorbent for albumin adsorption: Cibacron Blue F3GA-Zn(II) attached microporous poly(HEMA) membranes

Abstract

Poly(2-hydroxyethyl methacrylate) [poly(HEMA)] membranes were prepared by UV-initiated photopolymerization of HEMA in the presence of an initiator (a-a-azobis-isobutyronitrile, AIBN). The triazine dye Cibacron Blue F3GA was attached as an affinity ligand to poly(HEMA) membranes, covalently. These affinity membranes with a swelling ratio of 58% and containing 10.7 mmol Cibacron Blue F3GA/m 2 were used in the albumin adsorption studies. After dye-attachment, Zn(II) ions were chelated within the membranes via attached-dye molecules. Different amounts of Zn(II) ions [650-1440 mg Zn(II)/m 2 ] were loaded on the membranes by changing the initial concentration of Zn(II) ions and pH. Bovine serum albumin (BSA) adsorption on these membranes from aqueous solutions containing different amounts of BSA at different pH was investigated in batch reactors. The nonspecific adsorption of BSA on the poly(HEMA) membranes was negligible. Cibacron Blue F3GA attachment significantly increased the BSA adsorption up to 92.1 mg BSA/m 2 . Adsorption capacity was further increased when Zn(II) ions were attached (up to 144.8 mg BSA m 2 ). More than 90% of the adsorbed BSA was desorbed in 1 h in the desorption medium containing 0.5M NaSCN at pH 8.0 and 0.025M EDTA at pH 4.9.

Preparation of poly(2‐hydroxyethyl methacrylate)‐grafted chitosan‐montmorillonite superabsorbent nanocomposite for adsorption of bovine serum albumin

“…The isoelectric point of BSA is pI = 4.7, which indicates that it has a positive charge below this value and a negative charge above this value. Proteins do not have an electrical charge at their isoelectric points, and therefore the maximum adsorption capacity has been seen around pH = 5, which is the isoelectric point of BSA 26 . The adsorption capacity clearly increased when the solution pH from 3 to 5, and then steadily decreased as the solution pH increased further to 8.0.…”