双功能基团整体晶胶的层析性能与床层非均匀性研究

Chromatographic and Heterogeneous Properties of Monolithic Cryogels with Ion-Exchange and Hydrophobic Functional Groups

超大孔晶胶在生物技术领域有广泛的应用前景，研究具有新型功能基团的晶胶介质及其性能具有重要意义。今以N,N,N-三甲基乙烯基苯甲氯化铵为接枝单体，通过接枝修饰，制备得到具有离子交换和疏水双功能基团的聚丙烯酰胺基整体晶胶新介质，并对其基础和层析性能及床层非均匀性进行了研究。将晶胶床柱沿轴向分为四段，分别对其渗透率、孔隙率及在不同流速下的蛋白质吸附层析和轴向分散性能进行了实验研究。结果表明，该晶胶对牛血清蛋白的吸附容量随pH和流速而变化；在2cm·min^-1的流速下，当pH为5．0时最大吸附容量达7.3mg·mL^-1晶胶柱，且吸附容量随流速增大而略有减小。沿床层轴向由顶到底晶胶的基础性能参数和吸附容量呈现差异性，在流速1～6cm·min^-1下其平均蛋白质吸附容量分别为2．41、2．14、2，58和2．57mg·mL^-1晶胶，相同流速下各段吸附容量间的差异达9.33％～16．15％；其渗透率和流速1～10cm·min^-1等板高度等基础性能参数间的相对差异达6．46％和21．05％。

Supermacroporous monolithic cryogels have wide applications in biotechnology, and preparation and characterization of cryogels with various functional groups are of great importance. Cryogel beds with a combination of ion-exchange and hydrophobic functions were prepared by grafting （vinylbenzyl） trimethylammonium chloride onto polyacrylamide-based cryogel matrices. Chromatographic performance, heterogeneous characteristics and other properties along the axial bed height were investigated. The cryogel bed was divided into four sections along the bed height. Permeability, porosity and protein adsorption and axial dispersion under various flow rates in each of these sections were measured. The results show that the adsorption capacity of bovine serum albumin changes with the buffer pH values and flow rates. A maximum protein adsorption capacity of 7.3 mg·mL^-1 cryogel bed is achieved under conditions of pH 5.0 and flow velocity 2 cm·min^-1, and the adsorption capacity decreases with the increase of flow rate. The physicochemical properties and protein adsorption capacities varied slightly along the bed height. The average protein adsorption capacities are 2.41, 2.14, 2.58 and 2.57 mg·mL^-1 when the flow rate changes from l to 6 cm·min^-1. The maximum deviation of protein adsorption capacities among these four sections changes from 9.33 to 16.15% under same flow velocity, while that of water permeabilities and height equivalent to theoretical plate values （flow rates 1-10 cm·min^-1） are 6.46% and 21.05%, respectively. Heterogeneous characteristics along the axial bed height were expected in the present cryogels.