新型有机硅接枝聚合物的制备及其用于酸碱蛋白质分离机理的研究

The separation of a mixture of basic and acidic proteins is complicated by their tendency to adsorb onto the negatively charged surface of silica capillaries. Numerous approaches have been explored to minimize this adsorption. The most common approach has been to coat the capillary wall. A few separation mediums, such as homopolymer, block copolymer and graft copolymer, have recently been evaluated in our group as a suitable coating suppressing EOF and allowing separation of basic proteins. The results appear that changing the structure of the polymer seems to change the separation ability. Therefore, in order to solve the core problem on the capillary coating and the separation of basic and acidic proteins in the same time, we take account of introducing polyether and poly(4-vinyl pyridine) into silicone by polymer molecular design method, and then using this polymer as a novel and adsorbed capillary coating for electrophoretic protein analysis. First, in an effort to overcome the problem of the coating hydrophilic/lipophilic ability, polyether modified silicone is synthesized. Then, the macroinitiator is synthesized by adding 2-bromoisobutyryl bromide to react with the hydroxyl. Finally, the atom transfer radical polymerization (ATRP) of 4VP is carried out to obtain a pH-responsive polymers. Due to the fact that the structure could be modulated by changing the main chain and graft chain, this novel coating could exhibit for the separation of proteins with high separation efficiency, protein recovery, reproducibility of migration time and retention of the electroosmotic flow (EOF). So the basic and acidic proteins can be separated in the same run. We used quartz glass to simulate the capillary inner wall and study the coating surface state and principle. Trying to establish a link between polymer structure and separation performance by experiments. All these studies will provide new thought and method for development of high performance capillary coating.

酸碱混合蛋白质的分离是毛细管电泳技术发展的重点与难点。其中，毛细管涂层技术是解决这一问题的关键。我们曾采用均聚物、嵌段和接枝聚合物对某一类标准蛋白质进行了分离研究，发现聚合物的结构与分离性能存在联系。因此，我们拟针对涂层技术目前发展中所遇到的核心问题，提出了采用聚合物分子设计的方式，合成一种新型的有机硅接枝聚合物。首先，采用聚醚改性接枝，对有机硅主链的亲水/疏水性进行调节；然后，通过羟基与α-溴代异丁酰溴反应制得大分子引发剂；最后，采用原子转移活性自由基聚合方法，接枝有pH敏感性的P4VP链段。通过对主/支链的控制，从而对涂层的涂覆性、稳定性、分离效率、电渗流等进行调节，实现标准酸碱蛋白质在毛细管中的同时分离，并获得较好的分离效果和重现性。采用石英玻璃模拟毛细管内壁，研究涂层在其表面涂覆的状态和机理，建立起聚合物结构和分离性能的联系。此研究将为开发高性能的毛细管电泳涂层提供新的思路和方法。

毛细管内的涂层技术是毛细管电泳分离蛋白质或DNA的重点与难点。我们合成了一种新型的有机硅接枝聚合物。采用核磁，红外等技术对聚合物进行了表征，验证了目标产物的结构。对涂层在毛细管内的涂覆性、稳定性、分离效率、电渗流等进行实验，完善了涂层的性能。从而实现标准蛋白质或DNA在毛细管中的分离，并获得较好的分离效果和重现性。采用扫描电镜（SEM）研究了涂层在玻璃表面涂覆的状态和机理，为开发高性能的毛细管电泳涂层提供新的思路和方法。合成了一种基于纤维素的水凝胶，并对其结构进行了表征，最后进行了细胞培养实验证实了该水凝胶是一种性能优良的材料，可用于毛细管电泳中。另外，合成了基于偶氮苯的光响应水凝胶，系统研究了该水凝胶的溶胶-凝胶转变行为和流变学行为，为后续研究该材料在毛细管凝胶电泳中的应用提供了理论指导。