【作者】 李晓峰；

【导师】 闫兵；

【作者基本信息】 山东大学 ， 药物化学， 2009， 硕士

【摘要】 纳米材料因独特的物理化学性质,吸引了众多学者的研究兴趣,其中纳米材料作为药物载体在生物医学领域的研究正在迅速形成研究者们关注的焦点。碳纳米管(CNT)因其在生物学及医药领域的潜在应用而广泛受到人们的关注。碳纳米管被注射到动物体内后,可以通过血液循环进入器官和细胞,与蛋白质或DNA分子结合。这些性质使生物相容性好的CNT可能成为分子探针、药物载体、成像试剂、DNA调节剂等医学材料。碳纳米管的生物活性可通过表面官能团修饰、使用表面活性剂或链接生物大分子等方法得到改善。而将小分子化合物修饰到CNT表面是改善功能化碳纳米管的生物活性及其生物相容性的有效手段。本文利用QCM技术研究了三种多壁碳纳米管与五种物理化学性质不同的蛋白质的结合情况,并重点研究静电作用和疏水作用对功能化多壁碳纳米管(MWNT)与蛋白质间相互作用的影响,旨在建立一个实时研究纳米材料与生物大分子相互作用的的平台。首先,利用QCM技术测定MWNT-COOH与五种重要蛋白质间的动力学常数;其次探讨了静电作用和疏水作用对MWNT-COOH与蛋白质相互作用的影响;最后测定了血红蛋白与三种MWNT的结合量及结合速率。通过研究我们发现五种物理化学性质不同的蛋白质与MWNT-COOH的结合是不可逆的;静电作用可使MWNT-COOH与蛋白质的相互作用减弱;疏水作用增强会增强MWNT-COOH与蛋白质的相互作用;三种不同表面修饰的MWNT对Hb的结合量大小顺序为MWNT-Tyr＞MWNT-iBA＞MWNT-COOH。论文得到如下结论:1.五种物理化学性质不同的蛋白质可以与羧基化多壁碳纳米管表面发生不可逆结合;2.石英晶体微量天平技术作为一种动力学研究手段,不仅能够实时监测多壁碳纳米管与蛋白质之间的相互作用过程,并且可以给出其反应动力学常数,如结合常数,解离速率等;3.石英晶体微量天平技术可以直观的表征出多壁碳纳米管与蛋白质的不可逆结合受静电作用和疏水作用等物理性质的影响。本文首次将石英晶体微量天平技术用于表面功能化修饰的多壁碳纳米管与蛋白质间相互作用的动力学分析中,并对其影响因素进行研究,为下一步进行不同化学表面修饰的碳纳米管选择性结合蛋白质的研究打下基础。可为碳纳米管的生物毒性、研究其是否适合做药物载体及可控性地合成生物相容性良好的功能化碳纳米管等方面提供理论支持。以QCM技术为研究手段,建立一个纳米材料与生物大分子动力学研究平台,对于纳米医学研究具有一定意义。更多还原

【Abstract】 Nanomaterials have attracted many interests for their unique physicochemical properties,which make them have potential applications in many fields,especially in biomedicine,including diagnostics and therapeutics.Carbon nanotubes(CNT) have been widely studied for their potential applications in biology and medicine. CNT can enter various organs and cellular compartments and bind to protein and DNA molecules when they are injected into organism. These properties offer functionalized nanotubes tremendous opportunities to function as intracellular probes,drug carriers,imaging agents,DNA modulators,and other medical devices on the condition that they are biocompatible.The bioactivity of carbon naonotube is modulated by its surface chemistry,surfactant,and other factors.It is an effective method to obtain nontoxic and biocompatible nanotubes by modifying with small chemical reagents.A clear understanding of how nanotubes interact with proteins is a prerequisite for nanomedicine and nanotoxicity.This thesis monitored the interactions of three functionalized multi-walled carbon nanotubes(MWNT) and five proteins with different physicochemical properties,and focused on the kinetics studies and influence factors of MWNT -protein interactions by quartz crystal microbalance.We aimed to establish a novel method for nanomaterials-biomolecules interactions.First,the kinetics constants between the interactions of carboxylated MWNT(MWNT-COOH) and five proteins were measured.Second,the interactions of MWNT-COOH and protein influenced by electrostaticity and hydrophobicity were monitored.Finally,the binding affinities and binding velocities of the interactions between hemoglobin and three MWNT were measured.The binding between MWNT-COOH and five proteins are irreversible. The MWNT-COOH-protein interactions can be influenced by electrostaticity and hydrophobicity.The sequence of binding affinities and binding velocities between hemoglobin and three MWNT are consistent:MWNT-Tyr＞MWNT-iBA＞MWNT-COOH.CONCLUSIONS:1.The binding between five proteins with different physicochemical properties and MWNT-COOH are irreversible;2.QCM is a potent technique for kinetics constants measurement of MWNT-COOH-protein interactions,including association constant and dissociation constant;3.It is intuitionistic to show the influence on MWNT-protein interactions by electrostaticity and hydrophobicity via QCM.SIGNIFICANCE:It was the first time to study the kinetics and influence factors of MWNT-protein interactions by QCM technique,which can give some theoretic supports to screen the functionalized MWNT specifically bind to proteins.These are useful for MWNT’ biotoxicity,drug delivery and biocompatible nanotubes synthesis.Quartz crystal microbalance is a novel method to monitor the kinetics between nanomaterials and biomoleculars.更多还原