Protein adsorption on functional hydrophilic polymer beads: role of structural properties and medium conditions

Acrylic polymer beads comprising a combination of 2-hydroxyethylmethacrylate (HEMA) with acrylic acid, dimethylaminoethylmethacrylate (DMAEMA), and methylmethacrylate were prepared by suspension copolymerization technique. In this study, we have examined the effects of polymer structural properties and medium conditions on the adsorption of plasma proteins, i.e. bovine serum albumin (BSA) and fibrinogen. The studies were carried out in dilute solutions and measurements of adsorbed proteins were realized by fluorescence spectroscopy. It was shown that the extent of protein adsorption depends upon the hydrophilicity and electrical charge of both of the polymeric surfaces and proteins. In addition, environmental conditions affect the adsorption behaviour by changing the structure of protein molecules. The maximum adsorption was observed on poly(HEMA-DMAE) beads for both of BSA and fibrinogen. For this polymeric structure multilayer BSA adsorption was observed in the range of 0.1–0.5 mg/ml solution concentration. For all surfaces, the adsorbed quantity of fibrinogen was greater than that of BSA.