Dual radiolabeling to study protein adsorption competition in relation with hemocompatibility

Abstract

Human fibrinogen (Fg) and albumin (HSA) were labeled with (3)H and (14)C, respectively. Dual counting allowed the adsorbed amount of the two proteins to be determined simultaneously. Single adsorption, adsorption of the two proteins in competition, but also exchange (substitution by molecules of the same nature) and displacement (desorption under the action of the other protein) experiments were performed on two model surfaces, glass and polystyrene (PS), as well as on pure polyvinylchloride (PVC-s) and on PVC from blood bag (PVC-b). As expected, the adsorbed amount of a single protein is higher on a hydrophobic compared to a hydrophilic surface. When the two proteins are adsorbed in competition, they are found in equal proportion on glass, while HSA is twice more abundant than Fg on PS and PVC-s and about six times more abundant on PVC-b. This trend is related to an increase of the water contact angle of the substrates. For PVC-b, the contact angle is affected by the presence of aliphatic components exposed at the extreme surface, as determined by angle-resolved X-ray photoelectron spectroscopy. In exchange and displacement experiments, the first adsorbed molecules remain dominating on PS while they can be removed from glass. Given the known importance of HSA and Fg adsorption for the fate of materials placed in contact with blood, the method described in this paper may be used as a first approach to orient the design of surfaces with improved hemocompatibility.

Competitive adsorption of fibrinogen and albumin and blood platelet adhesion on surfaces modified with nanoparticles and/or PEO

“…These concentrations insure the same ratio as in blood plasma; they are about 10 times lower than the concentration in plasma but are on the plateau of adsorption isotherms reported for pure proteins on glass and PS [14]. Substrates were incubated in the protein solution at 37 • C for 24 h. After protein adsorption, samples were rinsed, without being exposed to air, by adding 2 ml of PBS, stirring gently, pumping 2 ml of solution and performing this 6 times.…”

“…The substrates were studied as such or after conditioning by adsorption of Pluronic F68 or PLL-g-PEG. Adsorption was monitored using the two proteins radiolabeled with distinct radioisotopes [14]. Platelet adhesion was assessed using the quantification of lactate dehydrogenase activity, while the state of activation of adherent platelets was observed by scanning electron microscopy.…”

A review of protein adsorption on bioceramics

“…Another interesting aspect of protein adsorption to bioceramics is competition adsorption between two or more proteins on the same adsorbent surface [223][224][225]. Leo Vroman firstly observed that fibrinogen preferentially adsorbed onto tantalum surfaces from blood plasma.…”

Effect of Sodium Chloride on the Adsorption of Proteins from Pink Shrimp (<i>Pandalus eous</i>) onto Stainless Steel Surfaces

“…It is well known that myofibrillar proteins, including tropomyosin, are highly soluble in high ionic strength solvent, while sarcoplasmic proteins are soluble in water or low ionic strength solution (Shahidi, 1994). In a multi-protein system, the type and level of proteins could affect adsorption levels because of competitive adsorption among proteins (Nonckreman et al, 2007).…”