Interaction of fibrinogen with solid surfaces of varying charge and hydrophobic—hydrophilic balance

Brash, John L.; Uniyal, S; Pusineri, Christian; Schmitt, A.

doi:10.1016/0021-9797(83)90068-1

Cited by 66 publications

(18 citation statements)

References 11 publications

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“…3). The presence of different popula tions of adsorbed macromolecules, some that are irreversibly bound and some that can be readily exchanged, is supported by previous work by others [18,19]. Lastly, the present observations do not appear to be specific to this macromolecule-hemodialysis membrane combination since similar binding kinetics for polydisperse dextran sulfate to DEAEconjugated cellulosic hemodialysis mem branes have been recently reported [20],…”

Section: Discussionsupporting

confidence: 88%

Macromolecule Adsorption to Hemodialysis Membranes Depends on Molecular Size

Leypoldt

Gilson²,

Blindauer³

et al. 1992

Blood Purif

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Adsorption to hemodialysis membranes was studied by determining the binding kinetics of model macromolecules, poly-disperse DEAE dextran (molecular radii 10-70 Å), to an acrylonitrile-methallyl sulfonate copolymer membrane. Hemodialyzers were studied in a postdilution hemofiltration circuit where both blood path output and ultrafiltrate streams were returned to the reservoir. Changes in the reservoir concentration of and sieving coefficients for DEAE dextran were monitored over 24 h. Decreases (or increases) in reservoir concentration were assumed to result from adsorption to (or desorption from) the membrane. Small macromolecules adsorbed rapidly to the membrane but later desorbed. This rapid adsorption resulted in low initial sieving coefficients. Large macromolecules adsorbed slowly over the entire 24-hour study period. Additional experiments suggested that desorption of small macromolecules was due to displacement by large macromolecules. Adsorption and desorption of macromolecules to hemodialysis membranes are dynamic processes and depend on molecular size.

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Section: Discussionsupporting

confidence: 88%

Macromolecule Adsorption to Hemodialysis Membranes Depends on Molecular Size

Leypoldt

Gilson²,

Blindauer³

et al. 1992

Blood Purif

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“…It exhibits both reversible and irreversible aspects, which often seem to be in mutual contradiction. For example, adsorbed proteins can be exchanged with similar or different proteins from the bulk solution (2)(3)(4)(5). However, on the time scale of the experiments, only a limited population of adsorbed molecules seems to be "exchangeable."…”

mentioning

confidence: 99%

“…Scs(t) = Qvcot -Qv Cb(u)du Cb(t) V, [4] where Cb(t) represents the protein concentration of the solution in the cell at time t estimated by continuous recording of the activity A(t) at the outlet of the cell. The variation of cs with time was then analyzed with a least-squares fit, using the Langmuir model defined by dcs --kaCb(Csmax -cs) -kdCs.…”

mentioning

confidence: 99%

Adsorption/desorption of human serum albumin on hydroxyapatite: a critical analysis of the Langmuir model.

Mura-Galelli

Voegel

Behr

et al. 1991

Proc. Natl. Acad. Sci. U.S.A.

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We studied the adsorption of human albumin onto synthetic hydroxyapatite, using a radiotracer technique and a special flow cell. Adsorption was studied under various conditions corresponding to different thermodynamic paths. It appears that (i) as is' the usual case, the isotherms obtained within a short time range (a few hours) do not correspond to a true equilibrium situation; (ii) when the adsorption process is followed for longer times, which is necessary at low bulk concentrations, one always reaches the plateau surface adsorption; (ii,) this plateau value is independent of the "history" of the adsorption process and corresponds well to the jamming limit predicted by the random sequential adsorption model; and (iv) surface denaturation, leading to enhanced surface binding and thus decreasing desorption constants, is the important phenomenon that can partly and qualitatively explain our observations. Its time dependence, however, remains to be clarified.The adsorption of proteins from solution onto solid surfaces is a fascinating and complex process that is known to have great biological impact (1). It exhibits both reversible and irreversible aspects, which often seem to be in mutual contradiction. For example, adsorbed proteins can be exchanged with similar or different proteins from the bulk solution (2-5). However, on the time scale of the experiments, only a limited population of adsorbed molecules seems to be "exchangeable." In addition, when a protein solution in contact with a solid phase is suddenly replaced by buffer, generally only a small fraction of the adsorbed molecules are desorbed (3, 5). Moreover, it has progressively been recognized that the irreversible aspects of these processes increase significantly with the mean contact time between the proteins and the adsorbing surface (6, 7). This is explained by interfacial molecular denaturation, leading to stronger interactions between the adsorbate and the surface. The observations of Jennissen and Botzet (8, 9), who found desorption hysteresis in the phosphorylase bc/butylSepharose system, have been interpreted in this way. Another typical consequence of the apparent and partial "irreversibility" of the adsorption/desorption process is that the amount adsorbed is not a unique function of the concentration of the solution in "equilibrium" with the surface; the "history" of the process plays a significant role. When adsorption is performed in one step, with the surface brought directly into contact with a solution of bulk concentration cb, the amount adsorbed is different (often higher) than in the case of a step-by-step experiment (the bulk concentration is then increased stepwise up to cb).The purpose of the present paper is to go one step further in the analysis of this puzzling phenomenon of protein adsorption. Two questions will be addressed in the discussion of our experimental results. (i) Is it still possible to speak about "isotherms" and surface/solution "equilibrium" when dealing with some protein/adsorbent systems? (ii) Does ...

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“…Such processes have been observed for synthetic polymers (2) as well as for proteins (3,4) by means of radioactive labeling techniques. NevertHeless, and in spite of a great number of investigations, little is known about adsorption processes of macromolecules (5).…”

Section: Introductionmentioning

confidence: 98%

“…This interaction can then be followed by sequential, segmental, reptation-like adsorption of the molecule, in competition with the dynamic process of the formation and annihilation of links of previously adsorbed macromolecules. Finally, the diffusing molecules progressively replace those already adsorbed on the surface, completing the exchange process.Such processes have been observed for synthetic polymers (2) as well as for proteins (3,4) by means of radioactive labeling techniques. NevertHeless, and in spite of a great number of investigations, little is known about adsorption processes of macromolecules (5).…”

mentioning

confidence: 98%

Kinetics of exchange processes in the adsorption of proteins on solid surfaces.

Ball

Huetz

Elaı̈ssari

et al. 1994

Proc. Natl. Acad. Sci. U.S.A.

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The homogeneous exchange process whereby IgG molecules adsorbed onto latex particles are replaced by IgG molecules from the bulk solution was studied by means of ts radiolabeling. The exchange mechanism was Investigated on surfaces saturated with either labeled or unlabeled proteins in the presence of a solution of the opposite species in two sets of independent experiments. After rinsing of the surface by pure buffer followed by supplementary IgG adsorption, the exchange process.followed a kinetic law of first order with respect to the IgG molecules from the bulk solution, and the apparent exchange rate constant was (2.3 ± 0.4) x 10-5 cm hr'1.One of the main differences between adsorption processes of "small" molecules and of macromolecules on solid surfaces is that macromolecules can reach the surface by two different mechanisms (1): by direct adsorption or by a progressive exchange reaction. In the first case the molecules reach the adsorption surface directly on free available space. In contrast, for the exchange mechanism the molecules reach the surface by progressive removal of already-adsorbed macromolecules. This occurs in particular when the surface is saturated with preadsorbed molecules. This second process has never been observed in the adsorption of small molecules on surfaces.The physical origin of this second adsorption process lies in the fact that macromolecules interact with a surface through several links. These links along the macromolecule change with time, even if the molecule is in an equilibrium configuration. Interactions between macromolecule and surface must thus be considered as a dynamic and not a static process. Moreover, macromolecules are not rigid bodies. Thus, if such a molecule enters into the vicinity of a surface already covered by adsorbed macromolecules, it can change its conformation and diffuse into the adsorbed layer. Once part of the backbone of the diffusing molecule reaches the adsorption surface, it interacts with it. This interaction can then be followed by sequential, segmental, reptation-like adsorption of the molecule, in competition with the dynamic process of the formation and annihilation of links of previously adsorbed macromolecules. Finally, the diffusing molecules progressively replace those already adsorbed on the surface, completing the exchange process.Such processes have been observed for synthetic polymers (2) as well as for proteins (3,4) by means of radioactive labeling techniques. NevertHeless, and in spite of a great number of investigations, little is known about adsorption processes of macromolecules (5). Let us rapidly summarize the main results that have been established. (i) The affinity of proteins for a given surface usually increases with their molecular weight. High molecular weight proteins usually exchange preferentially with lower molecular weight adsorbed proteins (6, 7). (ii) The higher the hydrophobicity of the surface is, the larger is the adsorbed quantity (8, 9). (iii) These amounts are maximal for pH values close to the ...

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Interaction of fibrinogen with solid surfaces of varying charge and hydrophobic—hydrophilic balance

Cited by 66 publications

References 11 publications

Macromolecule Adsorption to Hemodialysis Membranes Depends on Molecular Size

Macromolecule Adsorption to Hemodialysis Membranes Depends on Molecular Size

Adsorption/desorption of human serum albumin on hydroxyapatite: a critical analysis of the Langmuir model.

Kinetics of exchange processes in the adsorption of proteins on solid surfaces.

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