Diamine-plasma treated and Cu(II)-incorporated poly(hydroxyethylmethacrylate) microbeads for albumin adsorption

Poly(2-hydroxyethylmethacrylate) (PHEMA) microbeads prepared by suspension polymerization were treated with diamine-plasmas (i.e. ethylene-diamine (EDA) and hexamethylene diamine (HMDA)) in a glow-discharge reactor in which the exposure time and glow-discharge power were changed between 5 and 30 min and 5 and 20 W, respectively. The amount of nitrogen deposition increased both with increase in exposure time and glow-discharge power. The maximum amounts of nitrogen deposition on the microbeads were 22.3 and 23.4 μmol g-1 with the EDA- and HMDAplasmas. Then, Cu(II) ions were incorporated onto the PHEMA microbeads by chelating with the nitrogen-carrying functional groups. Different amounts of Cu(II) ions (2.4-6.8 mg g-1) were incorporated on the PHEMA microbeads by changing the initial concentration of Cu(II) ions. Bovine serum albumin (BSA) adsorption onto the unmodified PHEMA, diamine-plasma treated PHEMA, and diamine-plasma treated Cu(II)-incorporated PHEMA microbeads was investigated. The nonspecific ads...