Department of Chemical Engineering, University of Delaware, Newark, DE 19716, USA.
J Chromatogr A. 2011 Dec 9;1218(49):8748-59. doi: 10.1016/j.chroma.2011.06.061. Epub 2011 Jun 22.
A wide variety of stationary phases is available for use in preparative chromatography of proteins, covering different base matrices, pore structures and modes of chromatography. There has recently been significant growth in the number of such materials in which the base matrix is derivatized to add a covalently attached or grafted polymer layer or, in some cases, a hydrogel that fills the pore space. This review summarizes the main structural and functional features of ion exchangers of this kind, which represent the largest class of such materials. Although the adsorption and transport properties may generally be used operationally and modeled phenomenologically using the same methods as are used for proteins in conventional media, there are noteworthy mechanistic differences in protein behavior in these adsorbents. A fundamental difference in protein retention is that it may be portrayed as partitioning into a three-dimensional polymer phase rather than adsorption at an extended two-dimensional surface, as applies in more conventional media. Beyond this partitioning behavior, however, the polymer-functionalized media often display rapid intraparticle transport that, while qualitatively comparable to that in conventional media, is sufficiently rapid quantitatively under certain conditions that it can lead to clear benefits in key measures of performance such as the dynamic binding capacity. Although possible mechanistic bases for the retention and transport properties are discussed, appreciable areas of uncertainty make detailed mechanistic modeling very challenging, and more detailed experimental characterization is likely to be more productive.
有各种各样的固定相可用于蛋白质的制备色谱，涵盖不同的基质、孔结构和色谱模式。最近，这种材料的数量显著增加，其中基质被衍生化以添加共价连接或接枝的聚合物层，或者在某些情况下，填充孔空间的水凝胶。本综述总结了这类离子交换剂的主要结构和功能特征，它们代表了这类材料中最大的一类。尽管吸附和传输性质通常可以在操作上使用，并使用与传统介质中蛋白质相同的方法进行现象学建模，但在这些吸附剂中，蛋白质的行为存在显著的机械差异。蛋白质保留的一个基本区别是，它可以被描绘为分配到三维聚合物相中，而不是在扩展的二维表面上吸附，这适用于更传统的介质。然而，超出这种分配行为，聚合物功能化的介质通常表现出快速的颗粒内传输，虽然在定性上与传统介质相似，但在某些条件下，它的传输速度非常快，足以在关键的性能指标如动态结合容量方面带来明显的优势。尽管讨论了保留和传输性质的可能机械基础，但存在相当大的不确定性，使得详细的机械模型非常具有挑战性，更详细的实验表征可能更有成效。
