Adsorption of human serum albumin (HSA) on modified PET films monitored by QCM-D, XPS and AFM

The adsorption behavior of human serum albumin (HSA) on differently modified poly(ethylene terephthalate) (PET) model film surfaces was studied using the quartz crystal microbalance (QCM), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) techniques. The aim was to evaluate the influence of different modifications of PET surfaces with selected polysaccharides (chitosan, fucoidan, chitosan sulfate) on HSA adsorption.As a first step, PET hydrophilicity was increased by alkaline hydrolysis. From these foils model PET films were prepared by the spin coating technique on a quartz crystal. Selected polysaccharides (chitosan, fucoidan and chitosan sulfate) were adsorbed from aqueous solutions on the PET surfaces. Adsorption of HSA on the films was monitored with QCM-D. The surface composition and morphology of the HSA covered PET films was analyzed using XPS and AFM.It was found that due to steric repulsion the chitosan, fucoidan and chitosan sulfate adlayers reduced HSA adsorption, especially in case of chitosan/fucoidan and chitosan/chitosan sulfate covered films.