Plasma protein adsorption

Golander C G, Lin Y S, Fllady V and Andrade J D 1990 Wetting and plasma-protein adsorption studies using surfaoes with a hydrophobieity gradient Colloids Surf. 49 289-302... 

Kurrat R, Wallvaara B, Marti A, Textor M, Tengvall P, Ramsden J J and Spencer N D 1998 Plasma protein adsorption on titanium Colloids Surf. B 11 187-201... 

We used an anti-DNA antibody as an exploratory model system. The antibody was monoelonal from mouse sourees and its subelass was IgM. Mouse IgG (MW 1.5 x 10 Da) and IgM (MW 9 X 10 Da) antibodies from normal plasma, and bovine serum albumin were used for the eontrol measurements. To prevent the nonspeeilie adsorption of proteins to the uneovered, bare Au site in the modified eleetrode surfaee, the DNA-modified eleetrode prepared by the standard proeedure was further treated with aqueous 2-mercaptoethanol solution and was used for the measurements. 

S Harnisch, RH Muller. Adsorption kinetics of plasma proteins on oil-in-water emulsions for parenteral nutrition. Eur J Pharm Biopharm 49(l) 41-46, 2000. 

Lestelius M, Liedberg B, Tengvall P (1997) In vitro plasma protein adsorption on co-functionalized alkanethiolate self-assembled monolayers. Langmuir 13 5900-5908... 

For pH sensors used in in-vivo applications, especially those in continuous pH monitor or implantable applications, hemocompatibility is a key area of importance [150], The interaction of plasma proteins with sensor surface will affect sensor functions. Thrombus formation on the device surface due to accelerated coagulation, promoted by protein adsorption, provided platelet adhesion and activation. In addition, variation in the blood flow rate due to vasoconstriction (constriction of a blood vessel) and sensor attachment to vessel walls, known as wall effect , can cause significant errors during blood pH monitoring [50, 126],... 

Plasma proteins decreased extraction recoveries from SPME by irreversible adsorption onto the fiber. PPT prior to SPME by addition of acid or methanol was used to overcome this problem. SPME sensitivity may also be improved by dilution of plasma samples with buffer or water. 

However, surface potential cannot be the unique criterion of non-thrombogenicity. The superficial distribution of the charged site plays an important role as far as plasma protein adsorption is concerned and, upon their adsorption, these biomolecules may trigger the coagulation cascade in spite of exposing a net negative charge to the bloodstream. 

It has been shown that plasma protein adsorption, which occurs as soon as blood comes into contact with a given surface, is clearly influenced by the local shear stress [7]. 

The packing material first described for direct injection of biological samples was prepared by simply saturating the accessible adsorption sites of a Cis reversed-phase silica with human plasma proteins (105). After saturation, the human plasma proteins were denatured at the external surface, and their native conformation was destroyed. With this treatment, the proteins formed a hydrophilic layer with weak ion-exchange properties, which provided protection from contact with the sample proteins, whereas the alkyl ligands inside the pores remained unchanged and thus served for analyte retention. The retention behavior of the saturated phase did not alter with this treatment, but the efficiency was reduced dramatically. Such protein-coated columns have shown a lifetime of several months (106). 

It appears from these data that adsorption to hydrophilic surfaces would be a viable strategy. Other research produced a similar conclusion. Waugh et al. showed that prothrombin (another member of the coagulation cascade) binds more strongly to polymethyl methacrylate than glass, ("hating showed that plasma proteins bind more strongly to polyvinyl chloride than a hydrophilic dialysis membrane. 

Adams, et al. 101 used a curved disc on a flat surface to study the effect of solution volume at constant surface area on competitive plasma protein adsorption. Although the experiment was qualitative, it elegantly demonstrated the importance of exchange, bulk solution concentration, and surface-volume ratio on competitive adsorption 98>. 

Fig. 23. Brash and ten Hove s results on the adsorption of three plasma proteins from diluted plasma as a function of total plasma concentration. Up adsorption on glass showing a maximum adsorption of fibrinogen at about 1% plasma Down adsorption on polyethylene plasma was diluted with isotonic Tris, pH 7.35. Adsorption time was 5 minutes (reprinted from Ref.1031)...

Gregonis et al. have shown that PEO bound to quartz surfaces greatly minimizes the adsorption of proteins from plasma and from singly component protein solutions 122). Bell and coworkers at Los Alamos have developed a theory of cell-cell adhesion based on the steric repulsion characteristics of the hydrophilic macromolecules present on cell surfaces 124). 

The data on protein adsorption as affected by immobilized heparin is quite contradictory. In Refs.114> and115), serum albumin was shown to be predominantly adsorbed by the HCP, whereas in the majority of other works the observed dependence was the opposite. Table 14 compiles the results of the studies of the absorption of plasma proteins by HCP of two different types 64). Such thrombogenic proteins as fibrinogen and thrombin are seen to be the ones adsorbed most. 

We now may examine the relevance of surface tension measurements to interactions of cells in contact with serum or plasma. The surface tensions reported in Table I for the unfiltered liquids are much lower than those of the ultrafiltrates, at least in part, because of the adsorption of proteins having molecular weight > 20,000 at the liquid-air interface. And the measurements made on the ultrafiltrates are likely to be a good approximation to the zero-time surface tensions of the whole serum and plasma. The solutes that remain in the solution after ultrafiltration evidently are of a relatively low level of surface activity, and do not affect the surface tension to any greater extent than would be expected from their volume fractions. 

Immunoadsorption, an advanced therapeutic modality, focuses on detoxification of patient blood rich in high-molecular-weight pathogenic substances, mostly abnormal autoantibodies such as rheumatoid factors in rheumatoid arthritis (RA) and anti-DNA autoantibodies in systemic lupus erythematosus (SLE). Detoxification of these pathogens will be accomplished through extracorporeal perfusion of the patient plasma or whole blood over an affinity column made of immunoadsorbents. These adsorbents perform their function through the same mechanism as conventional affinity adsorption, where proteins in the liquid phase are adsorbed on the specific ligands immobilized onto an insoluble support. 

D3. Dantal, J., Bigot, E., Bogers, W., Testa, A., Kriaa, F., Jacques, Y., Hurault de Ligny, B., Niaudet, P., Charpentier, B., and Soulillou, J. P., Effect of plasma protein adsorption on protein excretion in kidney-transplant recipients with recurrent nephrotic syndrome. N. Engl. J. Med. 330, 7-14 (1994). 

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