Cd(II) removal from human plasma by cysteine-immobilized PHEMA microspheres

Poly(2-hydroxyethylmethacrylate), PHEMA, microspheres carrying cysteine were prepared and used for the removal of cadmium(II) ions from human plasma. PHEMA microspheres, in the size range of 150-200 μm in diameter, were produced by a modified suspension copolymerization of HEMA and EGDMA. Metal complexing aminoacid ligand cysteine was immobilized onto PHEMA microspheres. The maximum amount of cysteine-immobilized was 0.318 mmol/g. These hydrophilic microspheres with a swelling ratio of 58% (w/w), and carrying cysteine were used in Cd(II) removal studies in a packed-bed column system. The maximum amount of CD(II) removed from human plasma by cysteineimmobilized PHEMA microspheres was 0.065 mmol/g. Cd(II) ions could be repeatedly adsorbed and desorbed with these novel cysteine-immobilized PHEMA microspheres without noticeable loss in their adsorption capacity.