The Role of Polymer Nanolayer Architecture on the Separation Performance of Anion-Exchange Membrane Adsorbers: I. Protein Separations
The Role of Polymer Nanolayer Architecture on the Separation Performance of Anion-Exchange Membrane Adsorbers: I. Protein Separations
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DOI：
10.1002/bit.23221
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发表时间：
2011-11-01
影响因子：
3.8
通讯作者：
Husson, Scott M.
中科院分区：
文献类型：
--
作者：
Bhut, Bharat V.;Weaver, Justin;Husson, Scott M.
这一贡献描述了制备强阴离子交换膜具有更高的蛋白质结合能力比最好的商业树脂。在大孔膜载体表面接枝纳米膜，制备了季胺型（Q型）阴离子交换膜。这项研究的重点是更好地了解聚合物纳米层结构对蛋白质结合的作用。膜制备不同的聚合物链接枝密度使用新开发的表面引发的聚合协议，旨在提供均匀和可变的链间距。用牛血清白蛋白和免疫球蛋白G测定不同大小蛋白质的结合容量。测量IgG的动态结合能力以评估聚合物链密度对大尺寸蛋白质在流动条件下对纳米层内结合位点的可及性的影响。IgG的动态结合能力随着聚合物链密度的增加而几乎线性地增加，这表明聚合物链之间的间距足以使IgG沿着所有沿着接枝的聚合物链进入结合位点。此外，IgG的高动态结合容量（>130 mg/mL）不依赖于线性流速，这表明IgG分子到结合位点的传质主要通过对流发生。总的来说，这项研究提供了明确的证据，大型生物制剂的动态结合能力可以更高的设计良好的大孔膜吸附器比商业膜或树脂离子交换产品。具体地，使用受控聚合导致具有独立于流速的高结合能力的阴离子交换膜吸附器，从而实现高通量。这项工作的结果应有助于加速膜吸附器在生物过程纯化步骤中的更广泛应用。Biotechnol. Bioeng. 2011; 108：2645-2653. (C)2011 Wiley Periodicals，Inc.
This contribution describes the preparation of strong anion-exchange membranes with higher protein binding capacities than the best commercial resins. Quaternary amine (Q-type) anion-exchange membranes were prepared by grafting polyelectrolyte nanolayers from the surfaces of macroporous membrane supports. A focus of this study was to better understand the role of polymer nanolayer architecture on protein binding. Membranes were prepared with different polymer chain graft densities using a newly developed surface-initiated polymerization protocol designed to provide uniform and variable chain spacing. Bovine serum albumin and immunoglobulin G were used to measure binding capacities of proteins with different size. Dynamic binding capacities of IgG were measured to evaluate the impact of polymer chain density on the accessibility of large size protein to binding sites within the polyelectrolyte nanolayer under flow conditions. The dynamic binding capacity of IgG increased nearly linearly with increasing polymer chain density, which suggests that the spacing between polymer chains is sufficient for IgG to access binding sites all along the grafted polymer chains. Furthermore, the high dynamic binding capacity of IgG (>130 mg/mL) was independent of linear flow velocity, which suggests that the mass transfer of IgG molecules to the binding sites occurs primarily via convection. Overall, this research provides clear evidence that the dynamic binding capacities of large biologics can be higher for well-designed macroporous membrane adsorbers than commercial membrane or resin ion-exchange products. Specifically, using controlled polymerization leads to anion-exchange membrane adsorbers with high binding capacities that are independent of flow rate, enabling high throughput. Results of this work should help to accelerate the broader implementation of membrane adsorbers in bioprocess purification steps. Biotechnol. Bioeng. 2011; 108: 2645-2653. (C) 2011 Wiley Periodicals, Inc.