In situ studies on protein adsorption onto a poly(2-methoxyethylacrylate) surface by a quartz crystal microbalance

We have reported that poly(2-methoxyethylacrylate) (PMEA) showed excellent blood compatibility though it had a simple chemical structure, and have been making efforts to clarify the reason for the blood compatibility. It is well-known that the adsorption behavior of the protein affects the compatibility. Therefore, the adsorption behaviors of bovine serum albumin (BSA) and human fibrinogen onto the surfaces of PMEA, poly(2-hydroxyethyl methacrylate) (PHEMA) and polypropylene (PP) were investigated by using a quartz crystal microbalance (QCM), where PHEMA and PP were selected as the representatives of hydrophilic and hydrophobic polymers, respectively. Both proteins were observed to adsorb onto all the polymer surfaces according to Langmuirʹs adsorption isotherm. The maximum adsorption amounts and the apparent association constants of the proteins for PMEA obtained from the isotherm were lower than those for PHEMA and PP. These results suggest that the interaction between PMEA and the proteins is weaker than the interaction with PP and PHEMA.