多功能生物纳米探针用于癌症诊断与药物传输

发布时间：2018-05-13 11:24

本文选题：磁性荧光纳米探针 + 聚多巴胺　；参考：《南京大学》2015年博士论文

【摘要】：纳米材料由于其尺寸小,比表面积大,易修饰,物理化学性质独特,生物相容性良好等优点,广泛应用于生物,医药,能源,催化和环境等领域。特别是通过与具有特异性识别能力的生物分子联用,构建多功能的纳米探针和药物载体,已应用于癌细胞的荧光标记、磁性分离、基因转染、热疗和药物治疗等众多领域。本论文致力于利用纳米材料的光、磁、热学性质来调控生物分子的催化、识别功能,以肿瘤细胞中异常表达的生物分子为靶标,构建多功能的生物纳米探针用于癌细胞特异性标记、靶向药物传输和可控释放。主要内容如下：1、多层核壳结构的磁性荧光纳米探针用于靶细胞成像与芯片内分离聚多巴胺不仅能够轻易地包附在各种界面和无机纳米粒子表面,而且在碱性溶液中能与具有亲核基团的生物分子高效偶联,是制备生物纳米探针的理想修饰界面。我们合成了一种多层核壳结构磁性荧光粒子Fe3O4/SiO2/CdSeTe@ZnS-SiO2/聚多巴胺,并通过聚多巴胺与氨基、巯基或羧基修饰的DNA适配体偶联,用于对靶向癌细胞表面受体的特异性识别和定量评估。同时,利用磁性荧光探针在微流控芯片中对两种白血病细胞HL-60和K562的混合样品进行了在线识别、荧光标记和磁性分离。与传统细胞分离方法相比,本方法具有步骤简便、操作时间短、分离效率和回收率高等特点,在生物样品的成像与分离领域有潜在的应用价值。2、DNA hybrid为纳米门的多功能介孔硅纳米载体用于药物靶向运输与可控释放理想的纳米药物载体具备以下特性：特异性地识别癌症细胞；到达靶细胞前药物零释放；被靶细胞内的引发剂触发并可控地释放药物。我们选取细胞内异常表达的microRNA为触发剂,设计了一种荧光示踪的、适配体靶向的纳米药物载体,考察了药物载体在靶细胞内的吸收、药物释放和治疗效果。该载体以可编码的DNA hybrid为纳米门,通过部分碱基互补配对将药物分子封装在纳米载体内部。结果表明,在适配体介导的内吞作用下,药物载体能够选择性地在HeLa细胞内富集,并被癌细胞内过表达的miR-21触发药物释放。同时,调节细胞内microRNA的表达水平能够调控药物的释放速度,这种药物和基因协同治疗的方法为人类疾病的个性化治疗提供了新的策略。3、基于MNAzyme原位扩增技术的多功能纳米器件用于细胞内microRNA的多通道成像,逻辑运算和可控药物释放microRNA在癌症的发生,发展,转移过程中起着重要的作用,是极具潜力的癌症诊断生物标志物和治疗靶点。但是microRNA在细胞内的表达水平比较低。我们利用具有光热性质的纳米金棒和具有催化活性的MNAzyme发展了一种可编码的多功能纳米器件,用于microRNA的特异性识别和原位扩增,考察了细胞内microRNA的多通道检测和可控药物释放。利用MNAzyme的可编码、特异性识别和催化切割能力,不仅能够构建turn-on的荧光探针,实现细胞内痕量microRNA的多通道检测和荧光成像,而且能够循环放大microRNA触发和控制药物释放的能力,增强药物载体的治疗效果,为疾病的诊断,预后监测,药物和基因联合治疗提供通用的一体化设计思路。4、多重温度响应的智能纳米载体用于活体内热控吸收与microRNA/ATP介导的可控释放在癌症的治疗过程中,提高药物载体的靶向性和可控性能够提高治疗效果,减轻副作用。我们构建了一种多重温度响应的、表面性质可调的智能纳米载体,用于siRNA和Dox的靶向运输与同步可控释放。纳米载体表面的PEG壳层有效延长了载体在血液中的循环时间,减轻了血液中酶类对siRNA的降解,增加了载体在肿瘤部位的被动富集。通过近红外激光控制,实现了纳米载体在细胞和活体肿瘤组织的特异性识别与吸收。同时选择细胞内过表达的microRNA为引发剂,ATP为燃料分子,通过触发Toehold介导的级联扩增反应实现了siRNA/Dox的同步释放,提高了治疗效果,有效抑制了肿瘤的生长,达到了协同治疗的作用。
[Abstract]:Because of its small size, large surface area, easy modification, unique physical and chemical properties and good biocompatibility, nanomaterials are widely used in biological, medical, energy, catalysis and environmental fields. In particular, multi-functional nanoprobes and drug carriers have been used in combination with biological molecules with specific recognition ability, and have been applied to the application of nano probes and drug carriers. The fluorescent labeling of cancer cells, magnetic separation, gene transfection, thermotherapy and drug therapy. This paper is devoted to the use of the optical, magnetic and thermal properties of nanomaterials to regulate the catalysis of biomolecules and identify the functions of biomolecules expressed in tumor cells, and to construct a multifunctional biological nano probe for cancer cells. Specific markers, targeted drug delivery and controlled release. The main contents are as follows: 1, the magnetic fluorescent nanoprobes of multi-layer nuclear shell structures are used in target cell imaging and in chip separation polydopamine not only can easily be attached to the surface of various interfaces and inorganic nanoparticles, but also in alkaline solutions with nucleophilic groups. We have synthesized a multi-layer nuclear shell structure magnetic fluorescent particle Fe3O4/SiO2/CdSeTe@ZnS-SiO2/ polydopamine, coupled with the DNA aptamers modified by polyamine and amino, sulfhydryl or carboxyl groups to identify and quantify the specific surface receptor on the target cancer cells. At the same time, the magnetic fluorescence probe was used in the microfluidic chip to identify the mixed samples of the two leukemia cells HL-60 and K562 on line, the fluorescence labeling and the magnetic separation. Compared with the traditional cell separation method, this method has the advantages of simple steps, short operation time, high separation efficiency and high recovery rate, and the imaging of biological samples. With potential application value.2, DNA hybrid is a multifunctional mesoporous silicon nanoscale carrier for drug targeting transport and controlled release of nanoscale drug carriers with the following characteristics: specific identification of cancer cells; zero release of drugs before reaching the target cells; triggers in target cells and controllable. We selected the abnormal expression of microRNA as a trigger, designed a fluorescent tracer, an aptamer targeted nano drug carrier, investigated the absorption, drug release and therapeutic effect of the drug carrier in the target cells. The vector used the encoded DNA hybrid as the nano gate and the complementary pairing of some bases. The molecules are encapsulated inside the nanoscale. The results show that the drug carrier can be selectively enriched in HeLa cells and release the drugs over expressed miR-21 in the cancer cells under the aptamer mediated endocytosis. At the same time, the regulation of the expression level of microRNA in the cell can regulate the release rate of the drug, and this drug and gene are synergistic. The method of treatment provides a new strategy.3 for individualized treatment of human diseases. Multi-functional nanodevices based on MNAzyme in situ amplification technology are used for multichannel imaging of microRNA in cells. Logical operations and controlled drug release microRNA play an important role in cancer occurrence, development, and metastasis, which are potential cancers. Diagnosis of biomarkers and therapeutic targets. However, the expression level of microRNA in cells is low. We have developed a coded multifunction nano device using nano gold rods with photothermal properties and catalytic activity of MNAzyme to identify and amplify microRNA, and investigate the multiple channels of intracellular microRNA. Detection and controlled drug release. The coding, specific identification and catalytic cutting ability of MNAzyme can not only construct turn-on fluorescent probes, realize multichannel detection and fluorescence imaging of trace microRNA in cells, but also circulate and amplify the ability of microRNA to trigger and control the release of drugs, and enhance the therapeutic effect of drug carriers. For the diagnosis of the disease, the monitoring of the prognosis, the combination of drugs and gene therapy provides a general idea of integrated design.4. The multi temperature response intelligent nanoscale is used in the treatment of cancer by internal heat control absorption and microRNA/ATP mediated controlled release in cancer, improving the targeting and controllability of the drug carrier can improve the therapeutic effect and reduce the therapeutic effect. Light side effects. We have constructed a multi temperature responsive, intelligent nano carrier with adjustable surface properties for target transport and synchronous controlled release of siRNA and Dox. The PEG shell on the surface of nanoscale effectively prolongs the circulation time of the carrier in the blood, reduces the degradation of the enzymes in the blood and increases the carrier in the tumor part. By passive enrichment of the bit, the specific recognition and absorption of nanoscale in cell and living tumor tissues were realized by near infrared laser control. At the same time, the overexpressed microRNA was selected as the initiator and ATP was a fuel molecule. The synchronous release of siRNA/Dox was realized by triggering the cascade amplification reaction mediated by Toehold, and the therapeutic effect was improved. Fruit can effectively inhibit tumor growth and achieve synergistic treatment.

【学位授予单位】：南京大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TB383.1;R730.4

【共引文献】