Dextran-grafted cation exchanger based on superporous agarose gel: Adsorption isotherms, uptake kinetics and dynamic protein adsorption performance

Shi, Qinghong; Jia, Guo-Dong; Sun, Yan

doi:10.1016/j.chroma.2010.05.065

Cited by 62 publications

(33 citation statements)

References 43 publications

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“…Moreover, it was evident from values of e p for g-globulin that dextran-grafting had an obvious influence on e p and the effective porosity decreased from 0.50 to 0.44 with an increase in the dextran content of adsorbents. It was considered that the grafted dextran partially occupied the pore volume, giving rise to the smaller accessible pore space [32,40]. The result of e p in Tables 1 and 2 also indicated that the type of ligands had no influence on e p .…”

Section: Major Properties Of Adsorbentsmentioning

confidence: 80%

“…For a wellmixed vessel, the liquid-film mass transfer resistance can be neglected and the mass transfer of the protein from bulk liquid phase to the surface of the solid phase is expressed by [32,38] …”

Section: Uptake Kineticsmentioning

confidence: 99%

“…The ion-exchange capacities of SP-SEP, SP-D1-SEP, SP-D2-SEP and SP-D3-SEP were measured by acid-base titration as described previously [8,32]. The densities of AN ligands of MMC adsorbents were determined by acid-base titration described by Shi et al [31].…”

Section: Characteristics Of Adsorbentsmentioning

confidence: 99%

“…The dextran-grafted adsorbents with SP and AN ligands were fabricated in 50-mL flask as described by Shi et al [32]. After Sepharose FF stored in 20% ethanol aqueous solution was rinsed with distilled water and drained on a G3 sintered glass filter, 2 g of drained Sepharose FF was mixed with 1 mol/L NaOH (4 mL), ECH (2 mL) and dimethyl sulfoxide (DMSO, 4 mL).…”

Section: Fabrication Of Adsorbentsmentioning

confidence: 99%

“…In the preparation of IEC adsorbents, functional SP group was introduced by the following procedure [32]. In brief, after the activated bead was washed with distilled water, 2 g of drained beads were mixed with 0.4 g of sodium metabisulfite and 10 mL of distilled water.…”

Section: Fabrication Of Adsorbentsmentioning

confidence: 99%

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Effect of dextran layer on protein uptake to dextran‐grafted adsorbents for ion‐exchange and mixed‐mode chromatography

Shi

Sun

2011

J of Separation Science

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In the current research, a series of dextran-grafted adsorbents were prepared using sulfopropyl and 4-(1H-imidazol-1-yl) aniline as chromatographic ligands for ion-exchange (IEC) and mixed-mode chromatography (MMC) to respectively investigate the influence of dextran layer on adsorption of γ-globulin. Experimental evidences of static adsorption on dextran-grafted IEC adsorbents showed that adsorption capacity of γ-globulin increased with dextran content. It could be attributed to the multilayer adsorption of charged protein in dextran layer and thus further induced a significant electrical potential gradient at the boundary of adsorbed area and its proximity, improving mass transfer in combination with concentration gradient. In contrast to IEC adsorbents, adsorption capacity and effective diffusivity of dextran-grafted MMC adsorbents did not change obviously with dextran grafting. It was considered that hydrophobic ligands immobilized onto dextran-grafted MMC adsorbents were stuck together at pH 8.0, resulting in the collapse of dextran layer. In concert with measured effective porosity for γ-globulin at pH 4.0, it was confirmed that dextran layer in MMC adsorbent was more complicated and influenced significantly by buffer pH. It was also manifested by protein adsorption at different pHs. Thus, it revealed the complexity in intraparticle mass transfer of the protein in dextran-grafted MMC adsorbent.

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Section: Major Properties Of Adsorbentsmentioning

confidence: 80%

Section: Uptake Kineticsmentioning

confidence: 99%

Section: Characteristics Of Adsorbentsmentioning

confidence: 99%

Section: Fabrication Of Adsorbentsmentioning

confidence: 99%

Section: Fabrication Of Adsorbentsmentioning

confidence: 99%

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Effect of dextran layer on protein uptake to dextran‐grafted adsorbents for ion‐exchange and mixed‐mode chromatography

Shi

Sun

2011

J of Separation Science

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Surface DEAE groups facilitate protein transport on polymer chains in DEAE‐modified‐and‐DEAE‐dextran‐grafted resins

Gong

Bai

et al. 2016

AIChE Journal

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in Wiley Online Library (wileyonlinelibrary.com)Sepharose FF was modified with diethylaminoethyl-dextran (DEAE-dextran, DexD) and/or DEAE (D) to fabricate three types of ion exchangers FF-DexD (grafting-ligand resin), FF-D (surface-ligand resin), and FF-D-DexD (mixed-ligand resin), for protein adsorption equilibria and kinetics study. It was found that both adsorption capacity and uptake rate (effective diffusivity, D e ) were significantly enhanced by grafting DEAE-dextran. Notably, the D e values on FF-DexD and FF-D-DexD (D e /D 0 > 1.4) were six times greater than those on FF-D (D e /D 0 < 0.3). More importantly, the increase of surface-ligand density greatly enhanced uptake kinetics on FF-D-DexD. The results indicate that the surface ligands assisted the transport of bound proteins on polymer chains in the mixed-ligand resins. That is, surface ligands worked as "transfer stations" between two neighboring chains, resulting in enhanced transport of bound proteins on chains. The research thus disclosed the unique role of surface ligands in facilitating protein uptake kinetics onto polymergrafted ion-exchangers.The static adsorption equilibrium experiments of BSA on the resins were carried out in 20 mmol/L Tris-HCl (pH 8.0) as described earlier. 24 The adsorption density of protein (q) was calculated by mass balance with the free protein concentration in equilibrium (c), and the Langmuir model was used to describe the adsorption isotherms,The black lines represent agarose matrix, the blue curves represent dextran chains, the green lines represent the spacers, the red circles represent ion-exchange groups, and the pink and purple circles represent bound proteins. The dashed blue curves and faded circles represent the grafted polymer chains with adsorbed proteins after swing, and the dashed black boxes highlight the sites for the "relay"/delivery of proteins. The quantities of the dextran chains, spacers and the ion-exchange groups in this figure do not represent their real densities in the resins. In (a) it shows that the upper protein (pink) on the chain is delivered while the lower one (purple) is not. In (b) it shows that chain delivery occurs for the lower protein (purple), which was mediated by the surface DEAE ligands. [Color figure can be viewed in the online issue, which is available at wileyonlinelibrary.com.]

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Visualization and Modeling of Protein Adsorption and Transport in DEAE‐ and DEAE‐Dextran‐Modified Bare Capillaries

Xue

Sun

2018

AIChE Journal

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This article reports a microscopic method to directly visualize protein adsorption and transport in bare capillaries modified with ion exchange groups. Silica capillaries were coated with poly(vinyl alcohol) to eliminate nonspecific protein absorption and then functionalized with diethylaminoethyl (DEAE) and DEAE-dextran to prepare anion-exchange capillaries denoted as D-C and D-dex-C, respectively. Protein concentration profiles acquired from microscopic images were analyzed with a one-dimensional diffusion-adsorption model to determine adsorption capacities and effective diffusivities. It revealed that surface diffusion of bound protein on the capillary surface in D-Cs was negligible, but that of bound proteins markedly contributed to protein transfer in D-dex-Cs because of the chain delivery effect of charged dextran chains. The chain delivery was little affected by protein concentration, but significantly increased with ionic capacity. The research thus provided new insight into protein adsorption and transport behaviors on the surfaces modified with ion exchange groups of different structures.

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Dextran-grafted cation exchanger based on superporous agarose gel: Adsorption isotherms, uptake kinetics and dynamic protein adsorption performance

Cited by 62 publications

References 43 publications

Effect of dextran layer on protein uptake to dextran‐grafted adsorbents for ion‐exchange and mixed‐mode chromatography

Effect of dextran layer on protein uptake to dextran‐grafted adsorbents for ion‐exchange and mixed‐mode chromatography

Surface DEAE groups facilitate protein transport on polymer chains in DEAE‐modified‐and‐DEAE‐dextran‐grafted resins

Visualization and Modeling of Protein Adsorption and Transport in DEAE‐ and DEAE‐Dextran‐Modified Bare Capillaries

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