Bioseparations via Coupled TPP and Electrostatic Forces

CTS-0091552使用耦合TPP和静电力的生物分离Victor G. J. Rodgers（爱荷华州大学）Andrew L. Zydney（特拉华州大学）摘要膜过程在下游纯化广泛的生物产品中具有巨大的应用潜力。 然而，目前的装置受到缺乏选择性和与蛋白质结垢相关的问题的限制。 这项工作的目标是研究一种增强的膜分离技术的发展，该技术结合了使用界面电相互作用，以提高整体的选择性与跨膜压力脉冲（TPP），以减少膜污染和增加通量。最初的实验研究是使用定义明确的蛋白质溶液，含有一种或两种蛋白质和标准的超滤膜具有良好的特性。 将进行分批电解池和错流超滤（UF）实验，以评价模型单组分溶液和含和不含TPP的蛋白质二元混合物的转运。 在一系列缓冲条件下获得的数据表明使用具有不同表面电荷特性的膜来利用静电相互作用对分离的功效。通过毛细管电泳测定蛋白质电荷，并通过测量流动电位在每次运行之前和之后分析膜电荷。 操作后的解决方案分析和膜的水力渗透性数据用于定量确定膜污染的程度作为操作条件，膜表面特性和蛋白质性质的函数。 数据分析采用析因设计和方差分析（ANOVA）来识别改善溶质筛分、溶质通量和总体纯化因子的最显著因素。 这些实验研究得到了本体和膜传输现象的理论分析的补充，包括静电相互作用和跨膜压力脉冲的影响。动态TPP与静电相互作用的适当利用相结合有可能显着增强蛋白质分离膜的性能。 特别地，使用电相互作用来选择性地排斥带相同电荷的物质应该能够用市售的膜材料实现非常高分辨率的分离。 跨膜压力脉冲将允许这些装置在高得多的通量下操作，同时使膜污染最小化。 最终的结果是，该技术应该能够显着提高膜系统的总产量，纯化因子和通量特性，使这些设备被用于生物技术和生物医学工业中的一个全新的应用范围。 例如，由于膜过程固有地具有成本效益并且对脆弱的生物组分造成很小的损害，因此该技术的成功实施可以实现用于从天然来源如牛奶和血浆生产新的治疗性蛋白质和营养品的过程，用于从血浆中去除自身抗体的新生物医学装置的开发，或者用基于动态传质的人造器官治疗危及生命的疾病。

CTS-0091552Bioseparations using Coupled TPP and Electrostatic ForcesVictor G.J. Rodgers (University of Iowa) Andrew L. Zydney (University of Delaware)AbstractMembrane processes have great potential for use in the downstream purification of a wide range of biological products. However, current devices are limited by a lack of selectivity and problems associated with protein fouling. The goal of this work is to examine the development of an enhanced membrane separation technology that combines the use of interfacial electrical interactions to enhance the overall selectivity with transmembrane pressure pulsing (TPP) to reduce membrane fouling and increase flux. Initial experimental studies are using well-defined protein solutions containing either one or two proteins and standard ultrafiltration membranes with well characterized properties. Batch-cell and crossflow ultrafiltration (UF) experiments will be performed to evaluate the transport of model single-component solutions and binary mixtures of proteins with and without TPP. Data obtained over a range of buffer conditions indicate the efficacy of using membranes with different surface-charge characteristics to exploit electrostatic interactions on the separation. Protein charge is determined by capillary electrophoresis, and the membrane charge is analyzed both before and after each run by measuring the streaming potential. Post-operative solution analysis and membrane hydraulic permeability data are used to determine quantitatively the extent of membrane fouling as a function of operating conditions, membrane surface characteristics, and protein properties. The data analysis employs factorial design and analysis of variance (ANOVA) to discern the most significant factors in improving solute sieving, solute flux, and overall purification factor. These experimental studies are complimented by theoretical analyses of bulk and membrane transport phenomena, including the effects of both the electrostatic interactions and the transmembrane pressure pulsing.The combination of dynamic TPP with the proper exploitation of electrostatic interactions has the potential to provide significant enhancements in protein-separation membrane performance. In particular, the use of electrical interactions to repel selectively like-charged species should enable very high resolution separations to be accomplished with commercially available membrane materials. Transmembrane pressure pulsing will allow these devices to be operated at much higher throughput while minimizing membrane fouling. The net result is that this technology should be able to improve dramatically the overall yield, purification factor, and throughput characteristics of membrane systems, allowing these devices to be used for an entirely new range of applications in the biotechnology and biomedical industries. For example, because membrane processes are inherently cost effective and cause little damage to fragile biological components, successful implementation of this technology could enable processes for the production of new therapeutic proteins and nutraceuticals from natural sources like milk and plasma, the development of new biomedical devices for removal of auto-antibodies from plasma, or the treatment of life-threatening diseases with dynamic mass-transfer-based artificial organs.