【作者】 陈志萍；

【导师】 高保娇；

【作者基本信息】 中北大学 ， 军事化学与烟火技术， 2009， 博士

【摘要】 胆红素是血红素代谢降解的产物，是一种内源性毒素，血液中过高浓度的胆红素会导致梗阻性黄疸，甚至发生急性肾功能衰竭。同时，血液中胆红素含量的高低，是判断肝功能正常与否的一项重要指标，根据血液中胆红素的含量可诊断各种肝脏疾病。因此，清除血液中过高浓度的胆红素及胆红素含量的检测工作尤为重要。本研究依据材料分子设计的基本思想，研究制备了2种对胆红素具有良好吸附性能的功能材料，并制备了2种对胆红素分子具有特异识别性能的表面分子印迹材料，考查了它们对胆红素的吸附性能及分子识别特性，以期最终能分别应用于病患者血液中过高浓度胆红素的清除（血液净化吸附剂）与血液中胆红素浓度的检测（构建化学传感器）。首先以甲基丙烯酸缩水甘油酯（GMA）为单体，乙二醇二甲基丙烯酸酯（EGDMA）为交联剂，聚乙烯醇（PVA）为分散剂，偶氮二异丁腈（AIBN）为引发剂，采用悬浮聚合法制备了以GMA为主单体的二元共聚物交联微球CPGMA；考察了分散剂用量、搅拌速度、油水两相比例、交联剂用量、NaCl用量等因素对成球性能及微球粒径的影响规律。研究结果表明，通过控制各反应条件，可以制备出球形度极好、粒径可控的交联微球CPGMA，并确定了制备粒径在100μm左右的CPGMA微球的最佳条件。通过胺基与环氧键之间的开环反应，用己二胺、多乙烯多胺等小分子胺化试剂对CPGMA微球进行改性，制得了胺基化交联微球CPGMA，并研究了该功能微球对胆红素的吸附特性，考察了胺化试剂的分子结构、介质pH值、离子强度及温度等因素对其吸附性能的影响，较深入地研究了吸附机理。结果表明，胺基化微球对胆红素具有强吸附作用，吸附容量可达17．8 mg／g。胺化微球与胆红素分子之间的作用力以静电作用为主，同时也存在氢键作用与疏水相互作用。在pH=6时静电作用最强，胆红素吸附容量最高；高离子强度不利于静电相互作用，盐度增大使吸附容量减小。温度升高有利于疏水相互作用而不利于氢键作用，两种作用中占优势者主导温度对吸附容量的影响。用己二胺改性的微球，由于疏水相互作用的强化以及较长连接臂导致较小的空间位阻，使其对胆红素的吸附能力明显高于多乙烯多胺改性的微球。同样利用胺基与环氧键之间的开环反应，将聚胺大分子聚乙烯亚胺（PEI）偶合接枝在微球表面，制得了功能微球PEI-CPGMA，重点研究了功能微球对胆红素的吸附性能，考察了接枝度、介质pH值、离子强度等因素对微球吸附性能的影响。静态吸附实验结果表明，凭借强烈的静电相互作用与氢键相互作用，功能微球PEI-CPGMA对胆红素具有强吸附能力，饱和吸附量可达14．1 mg／g；介质的pH值对微球吸附性能有很大的影响，在近中性（pH=6）溶液中，接枝微球对胆红素的吸附能力最强；离子强度对吸附作用表现出微弱的增效作用；微球表面PEI的接枝度越高，吸附能力越强。采用溶液聚合法将甲基丙烯酸（MAA）接枝（逐步接枝）于硅胶微粒表面，制得了复合型吸附材料PMAA／SiO₂，并通过静态吸附实验研究了该功能微粒对胆红素的吸附性能。实验结果表明，接枝微粒PMAA/SiO₂对胆红素具有较强吸附作用。因此，在此基础上以胆红素为模板分子，乙二醇二缩水甘油醚（EGDE）为交联剂，对接枝在硅胶表面的PMAA大分子链进行了胆红素分子印迹，成功制备了胆红素表面分子印迹材料MIP-PMAA／SiO₂；采用静态与动态两种方法研究了MIP-PMAA／SiO₂对胆红素的结合特性。实验结果表明，印迹材料MIP-PMAA／SiO₂对胆红素分子具有特异的识别选择性与优良的结合亲和性，同时也具有优良的解吸性能，以EDTA与NaOH混合溶液作为洗脱液，10个床体积内解吸率可达99．48％。以γ-氯丙基三甲氧基硅烷为偶联剂，将大分子聚乙烯亚胺（PEI）接枝（偶合接枝）在硅胶微粒表面，成功地制备了复合型吸附材料PEI／SiO₂，通过静态吸附实验考察了接枝微粒PEI／SiO₂对胆红素的吸附性能，探索了各因素对其吸附能力的影响规律。实验结果表明，PEI／SiO₂对胆红素具有强的吸附能力，吸附体系的pH值、离子强度及PEI接枝度对PEI／SiO₂的吸附容量都有影响，其中以pH值的影响最为显著，在中性吸附体系中，PEI／SiO₂对胆红素的吸附量可达13．17 mg／g。因此，在此基础上以胆红素为模板分子，EGDE为交联剂，成功制备了胆红素表面分子印迹材料MIP-PEI／SiO₂；采用静态与动态两种方法研究了其对胆红素的结合特性。结果表明，印迹材料MIP-PEI／SiO₂对胆红素分子具有特异的识别选择性与优良的结合亲和性，同时也具有优良的解吸性能，11个床体积内解吸率可达99．39％。更多还原

【Abstract】 Bilirubin is a principal degradation product of heme catabolisma. High bilirubin concentration may cause obstructive jaundice, and further may results in acute renal failure. At the same time, serum bilirubin is an important index for judging the liver’s functions and identifying a variety of liver diseases. Therefore, the removal of high concentrations bilirubin and detection of bilirubin level are particularly important. In this study, based on the molecular design of materials, two kinds of functional materials with good adsorption properties for bilirubin and two kinds of bilirubin surface molecular imprinted polymers were prepared. And these materials were hoped to be applied in the removal of high concentrations of bilirubin （Hemoperfusion adsorbents） and testing （building of chemical sensors）, respectively.First, the crosslinking microbeads CPGMA with controllable size were synthesized by suspension polymerization of glycidyl methacrylate （GMA） and ethylene glycol dimethylacrylate （EGDMA）. The effects of various factors, such as disperser PVA weight percentage（wt%）, agitating rate, the ratio of oil phase to water phase, the weight percentage（wt%） of EGDMA and NaCl, on the sphericity and diameter of the microbeads were examined. The experimental results show that the sphericity of crosslinking microsbeads CPGMA is excellent and various factors the above-mentioned can all influence the particle diameter. And the optimal condition for prepareing CPGMA microsbeads with diameter about 100μm is determined.The crosslinking microspheres of CPGMA were modified chemically with aminating agents, hexanediamine and three kinds of multi-ethylene multi-amine. The effects of various factors, such as the chemical structures of the aminating agents, pH values of the medium, ionic strength and temperature, on the adsorption property of the functional microsphers for bilirubin were examined. The adsorption mechanism of the aminated microspheres towards bilirubin was studied more in depth. The experimental results show that the aminated microspheres has strong adsorption ability for bilirubin and the adsorption capacity can reach 17.8mg/g. Between the aminated microspheres and bilirubin molecules, electrostatic interaction is dominative, meanwhile, there are hydrogen bonding and hydrophobic interaction. As pH=6, the electrostatic interaction is the strongest, leading to the highest adsorption capacity. Higher ionic strength is disadvantageous to the electrostatic interaction, and the increasing of salinity conduces to the decreasing of the adsorption capacity. The rising of temperature is advantageous to the hydrophobic interaction, whereas is unfavorable to hydrogen bonding, and the predominated one between them dominates the effect of temperature on the adsorption capacity. The adsorption ability of the aminated microspheres modified with hexanediamine is stronger than that modified with multi-ethylene multi-amine owing to strengthening the hydrophobic interaction and smaller steric hindrance which comes from longer spacer.Polyethylenimine （PEI） was grafted on the surface of the CPGMA in the couple graft manner via the ring-opening reaction between the epoxy groups and the amino groups, and grafting microsphere PEI-CPGMA was obtained. The adsorption property of PEI-CPGMA for bilirubin was mainly studied, and the effects of various factors, such as pH value, ionic strength of the medium and the grafting degree of PEI, on the adsorption property were examined. The static adsorption experiment results show that PEI-CPGMA has a strong adsorption action towards bilirubin. The pH value of the aqueous solution has great effect on the adsorption property of PEI-CPGMA. In near neutral solution （pH=6）, there is maximum adsorption amount. The ionic strength of the medium exhibits little influence on the adsorption property of PEI-CPGMA. The higher the grafting degree of PEI on the microsphere surface, the stronger the adsorption capacity.PMAA was grafted onto the surface of silica gel particles via the coupling effect of MPS, and the grafting particle PMAA/SiO₂ was prepared. Then, using novel molecular surface imprinted technique, the molecular imprinted polymethylacrylic acid on the surface of silica gel, MIP-PMAA/SiO₂, was prepared with bilirubin as a template molecule and EGDE as crosslinking agent. Both static and dynamic methods were adopted to study the binding properties of MIP-PMAA/SiO₂ for bilirubin. The experiment results show that MIP-PMAA/SiO₂ have higher selectivity ability and excellent combination property for bilirubin. Besides, MIP-PMAA/SiO₂ has excellent elution property, with the mixed solvent of EDTA and NaOH as the eluent, the desorption ratios of bilirubin reach 99.48 % in 10 bed volumes.Polyethyleneimine （PEI） was grafted onto the surface of silica gel particles via the coupling effect of CP, and the grafted particle PEI/SiO₂ was prepared. Then, the molecular imprint polyethyleneimine on the surface of silica gel, MIP-PEI/SiO₂, was prepared with bilirubin as a template molecule and EGDE as crosslinking agent by using novel molecular surface imprinting technique. Both static and dynamic methods were adopted to study the identification properties of MIP-PEI/SiO₂ for bilirubin. The experimental results show that MIP-PEI/SiO₂ has higher selectivity ability and excellent combination property for bilirubin. Besides, MIP-PEI/SiO₂ has excellent elution property, with the mixed solvent of EDTA and NaOH as the eluent, the desorption ratios of bilirubin reach 99.39% in 11 bed volumes.更多还原