Competitive adsorption of plasma proteins at solid—liquid interfaces

Abstract

SUMMARYThe competitive adsorption of human serum albumin (HSA), human immuno-7-globulin (HIgG) and human fibrinogen (HFb) onto polystyrene (PS) at 20°C and a pH of 7.35 (phosphate-buffered saline) was studied. Protein adsorption was studied using enzyme immunoassay. The results obtained with the immunoassay were compared with those obtained using radiolabelled proteins. Recent studies revealed that the adsorption behaviour of radiolabelled proteins onto surfaces differs from that of the non-labelled proteins, which may lead to misinterpretation of adsorption data. Differences in the adsorption behaviour of the labelled proteins as compared to non-labelled proteins can possibly be explained by the formation of modified proteins during the labelling procedure as shown by ion-exchange high-performance liquid chromatography (HPLC). The competitive adsorption of HSA, HIgG and HFb onto a PS latex was studied by measuring the depletion of proteins in solution. The decrease in protein concentration in solution was determined by HPLC techniques. A strong preferential adsorption of HFb was observed with maximum adsorption values of 0.6 ug/cm 2.

pH-Dependent Adsorption of Human Serum Albumin Protein on a Polystyrene-Block–Poly(acrylic acid)-Coated PVDF Membrane

“…Thereby the greater propensity of the PS-b-PAA-coated membrane compared to the PM to adsorb HSA could be due to hydrophobic interactions between the hydrophobic parts of the protein and the accessible PS segments horizontally attached to the surface and not completely hidden by the PAA layer. Indeed, while our work showed a moderate adsorption of HSA on the PVDF pristine membrane, it was reported in the literature that HSA adsorbs strongly onto polystyrene plates and onto polystyrene latex [46].…”

Adsorption of human insulin and AspB28 insulin on a PTFE-like surface

“…Adsorption isotherms for other types of insulin (bovine and porcine) onto Teflon have been determined by isotope-labelled insulin [26]. This study led to surface coverage values significantly higher than in the present study, and furthermore a plateau of adsorption was not reached even Table 3 Dimensions and calculated monolayer coverage of the association states of insulin-where nothing else is indicated the data are taken from [39] [53]. Furthermore, the static experimental conditions and the use of Teflon disks with low surface area may also result in higher uncertainties of the measurements [26].…”

Preferential adsorption of bovine serum albumin dimer onto polymer microspheres having a heterogeneous surface consisting of hydrophobic and hydrophilic parts

“…The dimer/monomer ratio in the BSA solution before and after the adsorption was measured by high-performance liquid chromatogaphy (HPLC) (Tosoh, TSK-GEL 3000SW) using UV spectroscopy as the detection method [16]. The decrease in solution concentration of each protein was determined by measuring the specific peak areas of the HPLC chromatograms.…”