疏水电荷诱导亲和膜表面功能层的系统协同构建

The application of antibody and other proteins for therapy is a major revolution for biological pharmaceutical industry. But the antibody production requires an efficient separation method for significant cost reduction. Hydrophobic charge induction chromatography (HCIC) combines hydrophobic interaction and electrostatic interaction and therefore has the potential for massive production of antibody of high purity. But the current chromatography medium for HCIC is suffering from low efficiency and rare success of combining high adsorption capacity, high adsorption rate and high recovery. In this project, the idea of HCIC will be leveraged for membrane material design. The glass fiber microporous membrane having abundant silanol groups will be selected as the base to synthesize cost-effective membrane chromatography medium due to its superior heat resistance, chemical resistance, hydrophilicity as well as ease of modification. Sulfur-containing heterocyclic compounds were selected as HCIC ligands. We will explore simple, efficient and controlled polymer grafting chemistry to tether HCIC ligands onto membrane surface, therefore reversible protein adsorption-desorption can be manipulated by pH variation. We will tune the coupling chemistry, grafting density, the density and distribution of grafted polymers with pendant HCIC ligands, as well as their molecular weight, composition and topology so that ligands density, distribution and their intermolecular synergy can be optimized. In addition, thermo-responsive polymers will be introduced to promote the synergy of thermo-responsiveness and pH-responsiveness to pursue a higher antibody recovery. The ligand chemistry and the coupling chemistry will be optimized to promote the synergy of hydrophobic interaction and electrostatic interaction between ligands and proteins. With a solid understanding of the relationship between the microstructure of the functional layer and the membrane performance, we will be able to synthesize high performance hydrophobic charge induction affinity membranes. Based on this research, the convective transport and the macroporous structure occurred with polymeric membranes can be utilized to prepare a new kind of affinity membrane based on mixed interaction mode. Consequently, a new method for efficient antibody separation can be developed and the membrane application in bioseparation can be promoted.

抗体类诊疗蛋白的广泛使用是生物制药行业的革命，但其生产急需高效的纯化方法以降低工艺成本。基于疏水和静电作用偶合的疏水电荷诱导色谱（HCIC）具有大规模制备高纯度抗体的潜力，但其目前所用介质传质效率低，吸附容量、吸附速率和回收率难于兼顾。鉴于此，项目将HCIC的思想用于膜材料的设计，以玻璃纤维膜为基材，以含硫杂环化合物为配基，选取简单、高效、可控的接枝方法将其键连到膜表面，实现pH调控的蛋白吸附-解吸；系统调控接枝聚合物密度与分布、分子量、组成和拓扑结构以及偶联臂结构，优化配基密度与分布，实现配基分子间协同、温度响应性与pH响应性的协同、配基与抗体之间疏水和静电作用的协同；在总结膜表面功能层精细结构与膜性能关系基础上，制备高性能疏水电荷诱导亲和膜。本项目可望充分利用微孔膜的对流传质和大孔结构的优势，开发一种基于混合作用模式的新型亲和膜，发展抗体高效纯化的新方法，拓展膜材料在生物分离上的应用。

抗体类诊疗蛋白的广泛使用是生物制药行业的革命,但其生产急需高效的纯化方法以降低 工艺成本。基于疏水和静电作用偶合的疏水电荷诱导色谱(HCIC)具有大规模制备高纯度抗体的潜力,但其目前所用介质传质效率低，吸附容量、吸附速率和回收率难于兼顾。本项目充分利用微孔膜的对流传质和大孔结构的优势，开发一类基于混合作用模式的新型亲和膜，发展抗体高效纯化的新方法，拓展膜材料在生物分离上的应用。.从接枝方法、配体筛选、层析条件等三个方面优化亲和膜的制备。（1）首先发展了多组分反应和超支化修饰两种膜表面修饰的方法：通过多组分反应，一步法实现离子交换基团和疏水基团在膜表面的固载，制备两种基团均匀分布的混合模式吸附膜；用超支化接枝将兼具离子交换和疏水相互作用的疏水电荷诱导配基(HCIC) 接枝到膜表面，使配基在接枝层表面富集。同时，还将上述两种方法成功用于抗污染膜和脱硼吸附膜的制备。（2）其次借助石英电子天平和表面等离子体共振两种手段表征配体和目标抗体蛋白的相互作用，实现对配体的优选。在优化接枝方法和配体基础上制备了高容量的混合模式吸附膜，免疫球蛋白G (IgG) 的最大静态载量为182 mg/mL。（3）最后，针对动态吸附载量和抗体回收率，改变洗脱盐种类、浓度、pH值、流速，优化了层析效果。.需要提到的是，目前HCIC吸附膜的最高动态载量只有静态载量的1/3, 配基利用率较低，这也是这个领域的难题。我们认为, HCIC依靠较弱的疏水相互作用实现配基对目标蛋白的选择性吸附, 而蛋白质的疏水基团主要集中在内部,在动态过滤条件下,蛋白质链段来不及调节构象使疏水基团与配基相互作用。因此,如何制备兼具高动态载量和高回收率的HCIC吸附膜，是我们在现有项目资助下需要继续研究的关键问题。..相关部分研究成果已在J. Mater. Chem. A, Chem. Eng. J., Ind. Eng. Chem. Res., Appl. Suf. Sci.等本领域认可的学术期刊上发表 SCI 论文12篇; 2名博士生通过博士论文答辩, 获得博士学位; 8名硕士生通过硕士论文答辩, 获得硕士学位。