葡聚糖接枝型高载量金属螯合介质的制备与性能

对琼脂糖凝胶微球进行烯丙基活化，再接枝葡聚糖分子，考察葡聚糖分子量等因素对葡聚糖接枝过程的影响；以葡聚糖接枝琼脂糖凝胶微球为基质，制备亚氨基二乙酸型金属螯合介质，考察葡聚糖接枝过程对金属螯合介质的孔道结构、流通性能和载量等的影响. 结果表明，分子量20~500 kDa的葡聚糖都能均匀分布于琼脂糖凝胶微球内，葡聚糖接枝量随分子量增加而增大，所制的金属螯合介质形貌、粒径及其分布基本不受影响，且具有更好的流通性能，孔道结构比商品介质Ni Sepharose 6FF更丰富. 葡聚糖接枝的金属螯合介质对带组氨酸标签的乳酸脱氢酶和睫状神经营养因子的载量分别达到19和27 mg/mL，较Ni Sepharose 6FF的载量分别提高26.6%和42.0%.

Preparation and Properties of Dextran-grafted High Capacity Immobilized Metal Affinity Chromatography Media

Agarose microspheres were activated using allyl glycidyl ether, and further grafted with dextran molecules, and the effect of molecular weight of dextran on the grafting process was studied. Then iminodiacetic acid type immobilized metal affinity chromatography (IMAC) media were prepared using these dextran-grafted agarose microspheres as the matrix. The effects of dextran-grafting process on the pore structure, flow performance and capacity were examined. The results showed that dextran with molecular weight in the range of 20~500 kDa was evenly distributed inside agaroe microspheres, and the amount of dextran grafted increased with its molecular weight. The particle morphology, particle size and distribution of dextran-grafted IMAC media did not change obviously. However, dextran-grafted IMAC media possessed a better flow hydrodynamics property. Compared with the commercial chromatography media of Ni Sepharose 6FF, dextran-grafted IMAC media had a more abundant pore structure when the molecular weight of probe was between bovine serum albumin and ferritin. Binding capacity results indicated that its capacities for His-tagged lactate dehydrogenase and ciliary neurotrophic factor were 19 and 27 mg/mL, which were 26.6% and 42.0% higher than those of Ni Sepharose 6FF, respectively.