介孔硅和金属化合物基功能纳米材料的设计、制备及肿瘤治疗应用

发布时间：2018-06-08 21:26

  本文选题：介孔硅纳米粒子 + 层层自组装　； 参考：《东华大学》2015年博士论文

【摘要】：纳米科技的飞速发展极大推动纳米材料在生物医学中的应用。探寻高效、快捷的技术对纳米材料进行表面功能化修饰是推进纳米科技在生物医学等领域发挥应用的关键。在纳米医学领域中,开发出高效、稳定和安全的功能化纳米材料对癌症的治疗具有重要意义。针对癌症的治疗,构建具有“智能”响应性的药物控释体系和先进功能性的纳米材料,不仅能为抗癌药物运输系统的改善提供新的思路,而且为癌症治疗检测新模式的开展提供参考依据。为增强介孔硅纳米粒子(MSNs)、金纳米棒(Au NRs)以及二硫化钼(MoS2)等热点材料的生物安全性、提高载体药物控释的精度、提升材料的生物利用度、丰富材料的修饰手段并加强对癌细胞的杀伤效果,本博士论文以形态粒径可控无机纳米粒子的制备为起点,有机/无机功能化的设计为主线,良好的生物相容性为基准,高效抗癌纳米器件的构建为目标,开展一系列的研究工作。概括地讲,研究工作分为两个部分:第一部分以MSNs作为基底材料,着眼于p H响应性控释载体的设计和制备;第二部分以热点材料Mo S2和Au NRs为主体材料,分别构建出新型的光热剂和多功能纳米诊疗剂。详述如下:(1)基于“ph响应性控释载体”的设计理念,以msns为基底,选用合成高分子聚电解质聚烯丙基胺盐酸盐(pah)和聚苯乙烯磺酸钠(pss),采用层层(lbl)自组装方法对msns进行表面功能化修饰,并将阿霉素盐酸盐(dox)选作模型药物分子,制备出ph响应性药物控释体系。该工作首次考察自组装层数对药物缓释、细胞毒性和血液相容性的影响,并对载体的控释性能和生物安全性进行系统研究。聚电解质层(pah/pss)n的厚度与自组装层数2n呈指数关系。(pah/pss)n-msns具有良好的细胞相容性,不会引起溶血、血小板聚集,也不会激活凝血通路。ph值调控dox释放,药物释放速率随ph的降低而增加。癌细胞对dox@(pah/pss)4-msns的摄取能力明显强于正常细胞,该载药体系能有效抑制癌细胞生长。dox@(pah/pss)4-msns可以实现dox缓慢持续释放,从而延长dox在癌细胞的细胞核中的富集时间。动物体内分布实验表明,与纯dox相比,dox@(pah/pss)4-msns不仅可以维持稳定生物体的血药浓度,还可以减少药物在主要器官,特别是心脏部位的富集。(2)病理切片组织学检测中,虽然dox@(pah/pss)4-msns未引起明显的组织学损伤,但在脾脏和肺部中有出血或充血现象,分析可能原因是粒子在器官中发生聚集而引起的。粒子团聚势必会影响长期的生物安全性。在临床药物输送的应用中,载体材料需尽可能具备优异的生物相容性和生物可降解性,从而最大限度减小载体的有害副作用。考虑到除合成高分子聚电解质之外,天然聚电解质具有生物相容性好、来源丰富、降解产物对生物体无毒害以及能赋予载体新的功能基团等优点。我们继续沿用lbl自组装技术,msns作为基底,以天然大分子聚电解质壳聚糖(chi)和藻酸钠(alg)作为调控“开关”,构筑一套具有良好分散性、稳定性的ph响应性纳米控释体系。通过改进msns的制备工艺,并将组装层数控制在4层,成功地制备出具有“核壳”结构的(alg/chi)2-msns。该体系中粒子的平均粒径为167nm,具有良好的分散性和稳定性。ph调控dox释放,在低ph值体系中的药物释放速率要明显快于高ph值体系。体外细胞吞噬实验的结果表明,dox@(alg/chi)2-msns可以在癌细胞内持续释放dox,延长dox在细胞核富集时间,保持长期有效的治疗。药代动力学实验表明,与纯dox相比,dox@(alg/chi)2-msns在小鼠体内血液清除速率慢并且血液循环周期长,将dox的半衰期由64.8h延长至262.5h。该工作的意义不仅证明载药体系具有良好生物相容性的同时,进一步提升癌细胞对载药体系的摄取效率,而且载药体系中氨基和羧基等基团的引入,能为构筑多功能以及多重响应性载体(如靶向性或热敏性)的设计奠定基础。(3)基于“高效光热剂”的设计理念,针对目前光热剂mos2二维单层纳米片制备过程繁琐、片层厚度和尺寸难于控制等弊端,采用水热法,结合巯基化学,首次制备出形状和粒径可控,并具有胶体稳定性、良好生物相容性以及较高光热转换效率的新型光热剂——mos2-peg纳米花。mos2-peg纳米花能有效地将nir808nm的光能转换成热能,光热转换效率约为27.6%。该光热剂具有较强的光热杀伤效果,对癌细胞的细胞膜、溶酶体以及细胞骨架造成不可逆的杀伤,具备用于肿瘤的光热治疗的潜力。(4)基于“多功能高效光热剂”的设计理念,采用种子生长法制备金纳米棒(Au NRs),通过氧化聚合法成功地在Au NRs表面均匀包覆聚吡咯(PPY)层,不需要外加铁(Fe)源,原位对PPY外表面进行超顺磁氧化铁(Fe3O4)修饰,首次制备出多功能诊疗剂Au/PPY@Fe3O4复合纳米粒。Au/PPY@Fe3O4复合纳米粒子不仅展现出较强的磁性和较高的NIR吸收特性,而且能用于磁共振(MR)和X射线计算机断层扫描(CT)成像。Au/PPY@Fe3O4复合纳米粒子能有效地将NIR 808 nm的光能转换热能,光热转换效率约为23.9%。功率密度为2 W/cm2的NIR 808 nm激光照射10 min后,浓度为1.4mg/mL的Au/PPY@Fe3O4分散液温度升高35℃。体外细胞实验表明Au/PPY@Fe3O4复合纳米粒子具有良好生物相容性的同时,可以对癌细胞进行有效的光热杀伤。该工作为实现MR/CT成像监控的光热治疗提供可能性。综上,本论文分别对MSNs药物控释载体和功能性纳米光热剂在药物pH响应释放和癌症的光热治疗方面的应用展开了研究。期望以上研究工作能有力推进基于MSNs、Au NRs和MoS2等纳米材料在纳米医学上的应用,同时为癌症的治疗提供新的动力。
[Abstract]:The rapid development of nanotechnology has greatly promoted the application of nanomaterials in biomedicine. To explore the surface functional modification of nanomaterials by efficient and fast technology is the key to promote the application of nanotechnology in biomedicine and other fields. In the field of nanomedicine, the development of functional nanomaterials with high efficiency, stability and safety The treatment of cancer is of great significance. For the treatment of cancer, the construction of a "intelligent" responsive drug release system and advanced functional nanomaterials can not only provide a new way of thinking for the improvement of the anti-cancer drug transport system, but also provide a reference for the development of a new mode of cancer treatment and detection. The biosafety of MSNs, Au NRs, and molybdenum disulfide (MoS2), improves the precision of the drug controlled release of the carrier, improves the bioavailability of the material, enriches the modification methods of the material and strengthens the killing effect on the cancer cells. The design of inorganic functionalization as the main line, good biocompatibility as the benchmark, the construction of high efficient anti-cancer nanodevices as the target and a series of research work. In general, the research work is divided into two parts: the first part is based on MSNs as the base material, and focuses on the design and preparation of the P H responsive controlled-release carrier; the second part is a hot spot. Materials Mo S2 and Au NRs are the main materials, and the new photothermal and multifunctional nano diagnosis and treatment agents are constructed respectively. The following are as follows: (1) based on the design concept of "pH responsive controlled-release carrier", using MSNs as the base, synthetic polymer polyelectrolytes polyallyl amine hydrochloride (PAH) and polystyrene sulfonate (PSS) are selected, and layer (LBL) self-assembly is adopted. Methods the surface functional modification of MSNs was performed, and adriamycin hydrochloride (DOX) was selected as a model drug molecule, and the pH responsive drug controlled release system was prepared. This work was the first time to investigate the effects of the number of self assembly layers on drug release, cytotoxicity and blood compatibility, and systematically study the controlled release performance and biological safety of the carrier. The thickness of pah/pss n is exponentially related to the number of self assembled layers 2n. (pah/pss) n-msns has good cytocompatibility, does not cause hemolysis, platelet aggregation, nor activates the.Ph value of the coagulation pathway to regulate the release of DOX, and the rate of drug release increases with the decrease of pH. The ability of cancerous cell to dox@ (pah/pss) 4-msns is obviously stronger than that of normal. Cells, the drug delivery system can effectively inhibit the growth of cancer cells.Dox@ (pah/pss) 4-msns to achieve slow and sustained release of DOX, thus prolonging the accumulation time of DOX in the cell nucleus of cancer cells. In vivo distribution experiments in animals showed that dox@ (pah/pss) 4-msns, compared with pure DOX, could not only maintain the blood concentration of stable organisms, but also reduce drugs. The enrichment of the main organs, especially the site of the heart. (2) in histological examination, although dox@ (pah/pss) 4-msns does not cause obvious histological damage, there is bleeding or congestion in the spleen and lungs. The analysis may be caused by the aggregation of particles in the organs. In the application of clinical drug delivery, the carrier materials need to have excellent biocompatibility and biodegradability as far as possible, so as to minimize the harmful side effects of the carrier. We continue to use the LbL self-assembly technology, MSNs as the substrate, and use the natural macromolecule polyelectrolyte chitosan (chi) and sodium alginate (ALG) as the regulation "switch" to construct a set of pH responsive nano controlled release system with good dispersibility and stability. By improving the preparation of MSNs Art, and control the number of assembly layers on the 4 layer, successfully prepared (alg/chi) 2-msns. with a "nuclear shell" structure, the average particle size of the particle is 167nm, with good dispersion and stability,.Ph regulates DOX release. The release rate of the drug in the low pH value system is faster than the high pH value system. The results of the cell phagocytosis experiment in vitro The results showed that dox@ (alg/chi) 2-msns could release DOX continuously in the cancer cells, prolong the accumulation time of DOX in the nucleus and maintain long-term effective treatment. Pharmacokinetics experiments show that the blood clearance rate of dox@ (alg/chi) 2-msns in mice is slow and the blood circulation cycle is longer in mice compared with pure dox, and the half-life of DOX is extended from 64.8h to 262.5h.. The significance of the work is not only to prove that the drug system has good biocompatibility, but also to further enhance the uptake efficiency of cancer cells to the drug delivery system, and the introduction of amino and carboxyl groups in the drug carrying system can provide a basis for the design of multifunction and multiple responsiveness carriers (such as targeting or thermal sensitivities). (3) The design idea of the effective photothermal agent, in view of the tedious process of the preparation of the two dimensional single layer nanoscale of the current photothermal agent MoS2, the thickness and size of the lamellar layer is difficult to control. By using the hydrothermal method and the sulfhydryl chemistry, a new type of light with a controllable shape and particle size and a colloid stability, good biocompatibility and high photothermal conversion efficiency is made for the first time. Heat agent - mos2-peg nanoscale.Mos2-peg nanoscale can effectively convert the light energy of nir808nm into heat energy. The efficiency of photothermal conversion is about 27.6%., which has a strong photothermal killing effect, an irreversible killing on the cell membrane, lysosome and cytoskeleton of cancer cells, and has the potential of photothermal treatment for cancer. (4) In the design concept of "multi-function and high efficiency photothermal agent", gold nanorods (Au NRs) were prepared by seed growth method, and the polypyrrole (PPY) layer was successfully coated on the surface of Au NRs by oxidation polymerization. The superparamagnetic iron oxide (Fe3O4) modification was performed on the external surface of PPY without additional iron (Fe) source, and the multifunction diagnosis agent Au/PPY@Fe was prepared for the first time. 3O4 composite nanoparticles.Au/PPY@Fe3O4 composite nanoparticles not only exhibit strong magnetic properties and higher NIR absorption properties, but also can be used for magnetic resonance (MR) and X ray computed tomography (CT) imaging.Au/PPY@Fe3O4 composite nanoparticles can effectively transfer the energy of NIR 808 nm to heat energy, and the photothermal conversion efficiency is about 23.9%. power density. After 2 W/cm2 NIR 808 nm laser irradiated for 10 min, the temperature of Au/PPY@Fe3O4 dispersing solution with a concentration of 1.4mg/mL increased 35 C. In vitro cell experiment showed that the Au/PPY@Fe3O4 composite nanoparticles had good biocompatibility and effective photothermal killing on cancer cells. This work provided the photothermal treatment for the realization of MR/CT imaging monitoring. To sum up, we have studied the application of MSNs drug controlled-release carrier and functional nano photothermal agent in the response release of drug pH and the photothermal treatment of cancer. The above research work is expected to promote the application of nanomaterials based on MSNs, Au NRs and MoS2 and to provide new treatment for cancer. Power.
【学位授予单位】：东华大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TB383.1;TQ460.1
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本文编号：1997191