新型缩合反应在分子与细胞显像中的应用
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摘要
Click反应由于具有反应原料简单易得,产率高,反应条件简单和合成速度快速等优点,在药物开发和分子生物学的诸多领域中,已经被广泛关注,成为目前最为有用和吸引人的合成理念之一。
基于1,2-氨基硫醇和2-氰基苯并噻唑的缩合反应是发生在萤火虫体内的典型的Click反应,此反应具有反应条件温、具有良好的生物兼容性等优点,将反应底物加以修饰可通过调节pH,双硫键还原和酶切等条件诱发缩合反应的发生。也可以将反应底物修饰上不同的活性基团来应用于不同的领域,是非常具有前景的应用体系。
本论文基于这一缩合反应平台,修饰前体小分子,在不同的领域和体系内展开应用,主要分为三大部分：(1)以临床上使用的Gd-DOTA磁共振成像造影剂为前体小分子,以furin的底物为靶向基团,与1,2-氨基硫醇和2-氰基苯并噻唑缩合反应体系相结合,在体外缩合生成纳米粒子,合成新的磁共振成像剂,使其具有纳米材料造影剂优势的同时又具有靶向性。(2)以具有红色荧光的金属离子Eu代替具有磁共振成像的金属离子Gd,拓展了这一体系在双光子成像方面的应用。(3)运用Biotin-Streptavidin特异性结合体系,将Biotin修饰到缩合反应体系的前体小分子上,并连接与细胞凋亡相关的酶Caspase-3的底物作为靶向基团,在蛋白酶和还原剂的双重作用下,缩合生成表面富集Biotin的纳米粒子,加入SA-FITC后,荧光强度比未缩合的样品有明显的上升。
本论文以新型缩合反应为平台,拓展了这一体系在不同成像方法中的应用,这些成像方法不仅能够提高成像效率,而且具有靶向基团,使这些检测手段具有靶向作用,为分子成像的研究提供了新的方向。
Click chemistry has been widely noted because of its easy availability of raw materials, high yields, simplicity, mild reaction conditions, and high reaction rates. In recent decades, click chemistry has become one of the most useful and attractive concept in medicine and molecular biology.
The condensation reaction between2-cyanobenzothiazole (CBT) and D-cysteine is a classical click reaction happened in the body of firefly. This reaction has the advantage of mild reaction conditions and biocompatibility. Modification of the substrate can initiate the condensation reaction by changing the pH, reduction of disulfide bond, or enzyme cleavage. Fuctionalization of the monomer enables this reaction for broad biomedical applications.
This dissertation is based on this condensation reaction platform. We modified the substrate, and developed this reaction for molecular imaging. It can be divided into two parts:(1) The probe is linked with clinical contrast agents Gd-DOTA and combined with the peptide RVRR which is the substrate of furin. After condensation, nanoparticles were formed and can be trapped into the cells. The advantage of this kind of contrast agents is not only the nanomaterials known for us but also the targeting.(2) The fluorescence metal ion Eu replaces the magnetic resonance imaging metal Gd to develop the application of this condensation reaction for two-photon imaging.(3) The probe is linked with biotin which can bind with streptavidin specificly and combined with the peptide DVED which can be recognized and cleaved by caspase-3. After condensation, nanoparticles were formed and enriched with biotin. After adding streptavidin-FITC, the fluorescent intensity has an obvious enhancement than uncondensated one.
This dissertation is based on this condensation reaction platform, developed new applications in molecular imaging. These methods have the properties of not only enhancing the efficiency of molecular imaging but also targeting.
基于1,2-氨基硫醇和2-氰基苯并噻唑的缩合反应是发生在萤火虫体内的典型的Click反应,此反应具有反应条件温、具有良好的生物兼容性等优点,将反应底物加以修饰可通过调节pH,双硫键还原和酶切等条件诱发缩合反应的发生。也可以将反应底物修饰上不同的活性基团来应用于不同的领域,是非常具有前景的应用体系。
本论文基于这一缩合反应平台,修饰前体小分子,在不同的领域和体系内展开应用,主要分为三大部分：(1)以临床上使用的Gd-DOTA磁共振成像造影剂为前体小分子,以furin的底物为靶向基团,与1,2-氨基硫醇和2-氰基苯并噻唑缩合反应体系相结合,在体外缩合生成纳米粒子,合成新的磁共振成像剂,使其具有纳米材料造影剂优势的同时又具有靶向性。(2)以具有红色荧光的金属离子Eu代替具有磁共振成像的金属离子Gd,拓展了这一体系在双光子成像方面的应用。(3)运用Biotin-Streptavidin特异性结合体系,将Biotin修饰到缩合反应体系的前体小分子上,并连接与细胞凋亡相关的酶Caspase-3的底物作为靶向基团,在蛋白酶和还原剂的双重作用下,缩合生成表面富集Biotin的纳米粒子,加入SA-FITC后,荧光强度比未缩合的样品有明显的上升。
本论文以新型缩合反应为平台,拓展了这一体系在不同成像方法中的应用,这些成像方法不仅能够提高成像效率,而且具有靶向基团,使这些检测手段具有靶向作用,为分子成像的研究提供了新的方向。
Click chemistry has been widely noted because of its easy availability of raw materials, high yields, simplicity, mild reaction conditions, and high reaction rates. In recent decades, click chemistry has become one of the most useful and attractive concept in medicine and molecular biology.
The condensation reaction between2-cyanobenzothiazole (CBT) and D-cysteine is a classical click reaction happened in the body of firefly. This reaction has the advantage of mild reaction conditions and biocompatibility. Modification of the substrate can initiate the condensation reaction by changing the pH, reduction of disulfide bond, or enzyme cleavage. Fuctionalization of the monomer enables this reaction for broad biomedical applications.
This dissertation is based on this condensation reaction platform. We modified the substrate, and developed this reaction for molecular imaging. It can be divided into two parts:(1) The probe is linked with clinical contrast agents Gd-DOTA and combined with the peptide RVRR which is the substrate of furin. After condensation, nanoparticles were formed and can be trapped into the cells. The advantage of this kind of contrast agents is not only the nanomaterials known for us but also the targeting.(2) The fluorescence metal ion Eu replaces the magnetic resonance imaging metal Gd to develop the application of this condensation reaction for two-photon imaging.(3) The probe is linked with biotin which can bind with streptavidin specificly and combined with the peptide DVED which can be recognized and cleaved by caspase-3. After condensation, nanoparticles were formed and enriched with biotin. After adding streptavidin-FITC, the fluorescent intensity has an obvious enhancement than uncondensated one.
This dissertation is based on this condensation reaction platform, developed new applications in molecular imaging. These methods have the properties of not only enhancing the efficiency of molecular imaging but also targeting.
引文
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