Characterization of large-pore polymeric supports for use in perfusion biochromatography.
Characterization of large-pore polymeric supports for use in perfusion biochromatography.
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DOI：
10.1016/s0021-9673(98)00068-5
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发表时间：
1998-05
期刊：
影响因子：
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通讯作者：
D. Whitney;M. Mccoy;N. Gordon;N. Afeyan
中科院分区：
文献类型：
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作者：
D. Whitney;M. Mccoy;N. Gordon;N. Afeyan
灌注色谱的独特特点是部分柱洗脱液直接流过填充床中的树脂。这种现象的好处和灌注树脂的一些特性之前已经描述过，可以总结为增强了向内部结合位点的质量传递。在这里，我们通过比较不同孔径分布的树脂来扩展对这一现象的理解。所选择的树脂具有大致相同的比孔体积（如表征部分所示），但大孔的不同贡献用于控制流过微珠的液体量。POROS R1的通孔贡献最大，因此颗粒内流动最大。POROS R2的通孔贡献度较低，由于扩散孔数量较多，表面积增大，但相对于纯扩散控制，其质量输运仍有显著增强。Oligo R3主要由大量弥漫性孔隙组成，相对而言，它是一种非渗透性树脂。虽然可以设计孔径分布来控制质量传输速率，但产生的表面积并不是控制结合力的唯一手段。采用表面涂层来增加结合力而不从根本上改变质量输运性质。模型被用来描述横切珠子的流量，并将涂覆树脂与未涂覆树脂（聚苯乙烯）进行比较，得出这些涂层不会阻碍通孔结构的结论。这是一个重要的结论，因为在某些情况下，涂层产品的结合能力比前驱体聚苯乙烯支架（即POROS R1或POROS R2）高10倍以上。
Perfusion chromatography is uniquely characterized by the flow of a portion of the column eluent directly through the resin in the packed bed. The benefits of this phenomenon and some of the properties of perfusive resins have been described before, and can be summarized as enhanced mass transport to interior binding sites. Here we extend the understanding of this phenomenon by comparing resins with different pore size distributions. Resins are chosen to give approximately the same specific pore volumes (as shown in the characterization section) but the varying contribution of large pores is used to control the amount of liquid flowing through the beads. POROS R1 has the largest contribution of throughpores, and therefore the greatest intraparticle flow. POROS R2 has a lower contribution of throughpores, and a higher surface area coming from a greater population of diffusive pores, but still shows significant mass transport enhancements relative to a purely diffusive control. Oligo R3 is dominated by a high population of diffusive pores, and is used comparatively as a non-perfusive resin. Although the pore size distribution can be engineered to control mass transport rates, the resulting surface area is not the only means by which binding capacity can be controlled. Surface coatings are employed to increase binding capacity without fundamentally altering the mass transport properties. Models are used to describe the amount of flow transecting the beads, and comparisons of coated resins to uncoated (polystyrene) resins leads to the conclusion that these coatings do not obstruct the throughpore structures. This is an important conclusion since the binding capacity of the coated product, in some cases, is shown to be over 10-fold higher than the precursor polystyrene scaffold (i.e., POROS R1 or POROS R2).