Protein ion‐exchange adsorption kinetics

Wesselingh, J.A.; Bosma, J. C.

doi:10.1002/aic.690470710

Cited by 55 publications

(45 citation statements)

References 10 publications

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“…Multicomponent coupled diffusion and adsorption can cause concentration overshoots; as discussed earlier, however, we have gone to great lengths to ensure that such effects are absent for the lysozyme results, although they may contribute to the double rings seen for some other proteins. Purely electrostatic effects resulting from release of counterions from both protein and surface may be a factor, as may effects of coupled diffusion among these species (23). However, one would expect these effects to be most pronounced at very low ionic strengths, where our experiments show behavior completely consistent with the shrinking core model as expected, whereas our more surprising results are seen at moderately high ionic strengths.…”

Section: Fig 4 (A-e)contrasting

confidence: 53%

Nondiffusive mechanisms enhance protein uptake rates in ion exchange particles

Dziennik

Belcher²,

Barker³

et al. 2003

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

127

145

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Scanning confocal fluorescence microscopy and multiphoton fluorescence microscopy were used to image the uptake of the protein lysozyme into individual ion exchange chromatography particles in a packed bed in real time. Self-sharpening concentration fronts penetrating into the particles were observed at low salt concentrations in all of the adsorbents studied, but persisted to 100 mM ionic strength only in some materials. In other adsorbents, diffuse profiles were seen at these higher salt concentrations, with the transition region exhibiting a pronounced fluorescence peak at the front at intermediate salt concentrations. These patterns in the uptake profiles are accompanied by significant increases in protein uptake rates that are also seen macroscopically in batch uptake experiments. The fluorescence peak appears to be a concentration overshoot that may develop, in part, from an electrokinetic contribution to transport that also enhances the uptake rate. Further evidence for an electrokinetic origin is that the effect is correlated with high adsorbent surface charge densities. Predictions of a mathematical model incorporating the electrokinetic effect are in qualitative agreement with the observations. These findings indicate that mechanisms other than diffusion contribute to protein transport in oppositely charged porous materials and may be exploited to achieve rapid uptake in process chromatography.T he dramatic growth of the biotechnology industry in recent years has depended critically on preparative separation techniques for protein products. Ion exchange chromatography, introduced for protein separations in the 1950s, remains one of the most widely used preparative-scale purification and separation methods (1). Ion exchange adsorbents have been designed to offer a range of mechanical and chemical properties for chromatographic separation and purification (2), but a fundamental understanding of transport mechanisms in these materials remains elusive. For most materials, simple diffusive mechanisms are thought to control intraparticle transport, but studies using batch or column techniques (3-7) yield model-dependent transport coefficients, and they cannot definitively determine the physical transport mechanism. With the projected acceleration in the discovery and development of protein therapeutics as a result of the human genome project, the demand for improved chromatographic materials and methods for optimizing protein separation and purification will increase. Therefore, a more fundamental understanding of the transport mechanisms in these materials is required to develop better heuristics for process development as well as methodologies for the design of new adsorbents.A key complication in the interpretation of batch or column studies is that the transport is coupled to adsorption, making additional assumptions regarding the adsorption behavior necessary to characterize the transport. Microscopic techniques have a greater potential to resolve the resulting ambiguities regarding transport mechanisms...

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Section: Fig 4 (A-e)contrasting

confidence: 53%

Nondiffusive mechanisms enhance protein uptake rates in ion exchange particles

Dziennik

Belcher²,

Barker³

et al. 2003

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

127

145

View full text Add to dashboard Cite

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“…Experimental work by Rabe and Tilton (1993) and Bosma and Wesselingh (2001) gave similar values (ranging from 10 )13 to 10 )12 m 2 /s). We performed some prelimenary kinetic experiments of BSA adsorption with a comparable (MacroPrep 50Q), but not identical, resin under comparable conditions.…”

Section: Adsorption Kineticssupporting

confidence: 65%

“…Eective solid phase diusivities of proteins were estimated using the Two-Phase Diusion model by Bosma and Wesselingh (2001). This is essentially a parallel pore and surface diusion model:…”

Section: Mass Transfermentioning

confidence: 99%

Albumin recovery with centrifugal adsorption technology (CAT)

Peet

Bisschops²,

Hateren

et al. 2002

Biotech & Bioengineering

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Centrifugal adsorption technology (CAT) is a new compact, countercurrent technology for efficient adsorption from large liquid streams by using adsorbent particles in the micrometer range. CAT seems particularly suited for the recovery of macromolecules at low concentrations, because the small particle dimensions lead to fast mass transfer rates. In this work, the potential of CAT for protein recovery is studied by model and experiment. A predictive model for the separation performance of CAT is presented, incorporating mass transfer resistance and axial dispersion transport in the liquid and the adsorbent phases. The model calculations were compared to experimental data for the adsorption of bovine serum albumin (BSA) on a standard commercial anion-exchange resin with particle diameter d(p) = 50 microm in a pilot-scale CAT apparatus. The model calculations accurately predicted the separation efficiency of CAT. The experimental set-up is shown to be mass transfer limited for the conducted experiments, which agrees with the model predictions. The model was also used to estimate the dimensions and performance of a CAT apparatus for the large-scale recovery of human serum albumin (HSA) from fermentation broth at the scale of 40 tons per year. The resulting equipment dimensions proved to be very small indeed, making CAT a potentially very attractive technology.

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“…In this work, the nonuniform spatial charged ligand density distributions in porous polymeric adsorbent media determined from MD modeling (microscopic models whose expressions are based on fundamental physics and chemistry [25 -27]), are employed in a macroscopic model that in practice [4, 7 -10] could describe the adsorption of an adsorbate in spherical porous adsorbent particles immersed in a well-stirred finite bath [4,7,8,10,18]. This study allows us to investigate the dynamic behavior of the spatial distribution of the concentration of an adsorbate in the adsorbed phase and in the pore solution when the spatial distribution of the immobilized ligands is nonuniform.…”

Section: Introductionmentioning

confidence: 99%

Protein adsorption in porous adsorbent particles: A multiscale modeling study on inner radial humps in the concentration profiles of adsorbed protein induced by nonuniform ligand density distributions

Riccardi

Wang

Liapis³

2009

J of Separation Science

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Recently published results determined from molecular dynamics (MD) modeling and simulation studies have shown that the spatial distribution of the density of immobilized charged ligands in ion-exchange porous adsorbent particles is most likely nonuniform and the adsorbent particles also exhibit local nonelectroneutrality. In this work, the functional forms of the nonuniform spatial distributions of the density of the immobilized ligands in four different porous adsorbent media that were determined by MD studies were employed in a macroscopic continuum model describing the transport and adsorption of a single protein in the porous particles of the four different adsorbent media. The results clearly show that inner radial humps in the concentration profiles of the adsorbed protein can occur when the spatial distribution of the density of the immobilized ligands in the porous adsorbent particles is nonuniform and also has local maxima or minima along the radial direction in the particle. The results also indicate that the rate at which the equilibrium condition is approached depends significantly on the functional form of the spatial distribution of the density of the immobilized ligands. When adsorption equilibrium has been reached, the concentration profile of the adsorbed protein exhibits the shape of the spatial distribution of the density of the immobilized ligands. The results suggest that the technique of confocal scanning laser microscopy could be used to measure the concentration profile of an adsorbed protein at equilibrium and this measurement could provide the spatial distribution of the density of the immobilized ligands, and such measurements could also be used for quality control of the adsorbent medium. The results in this work have also implications in the modeling, design, analysis, and quality control of systems involving biocatalysis. Furthermore, the results clearly indicate that it is very important to study the dynamic behavior of an adsorption system having a nonuniform spatial distribution in the density of the immobilized charged ligands and where (i) both monovalent and multivalent interactions between the single charged adsorbate and the immobilized charged ligands occur and (ii) the values of the pH and ionic strength are such that the electrophoretic effects are active.

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Protein ion‐exchange adsorption kinetics

Cited by 55 publications

References 10 publications

Nondiffusive mechanisms enhance protein uptake rates in ion exchange particles

Nondiffusive mechanisms enhance protein uptake rates in ion exchange particles

Albumin recovery with centrifugal adsorption technology (CAT)

Protein adsorption in porous adsorbent particles: A multiscale modeling study on inner radial humps in the concentration profiles of adsorbed protein induced by nonuniform ligand density distributions

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