【作者】 郭明义；

【导师】 朱广山；

【作者基本信息】 吉林大学 ， 无机化学， 2011， 博士

【摘要】 本论文致力于硅基多孔材料的合成及其在药物传输体系中的应用研究。包括单质硅介孔的合成及其在药物缓释中的应用。利用纳米粒子做药物控制释放的“开关”,制备了一种基于介孔二氧化硅具有pH刺激-响应释放的药物输运载体,考察了该载体在抗癌药物传输上的应用。利用天然矿物埃洛石纳米管,制备了多功能的药物传输载体,并考察了载体的药物释放性能,对阳离子抗癌药物,体系显示了pH响应释放性质。介孔单质硅的合成是具有挑战性的课题,本论文中,我们利用镁热还原反应,以特定形貌和孔道结构的介孔二氧化硅为原料,制得了较高比表面积的介孔单质硅材料,考察了不同结构的前驱体对产物的影响,材料显示了良好的药物缓释效果。这一方法可以大量制备介孔单质硅材料,进而有助于开发其在光电、能量存储上的应用。基于介孔二氧化硅纳米材料的药物控制释放体系成为近年来的研究热点。我们利用氧化锌纳米粒子为“开关”,通过设计修饰介孔二氧化硅孔道的内外孔壁,成功的将氧化锌纳米粒子“锚定”在孔道口,同时利用氧化锌在生理环境pH环境下稳定存在,而在弱酸条件下可以被溶解这一特点,考察了该体系在不同pH下药物释放性能,在癌细胞弱酸条件下,体系也展示了良好的药物释放性能。另一方面,氧化锌在较高浓度下显示了细胞毒性,文献报道其具有对健康细胞和癌细胞选择性,因此该药物传输体系具有双重功能。此外,我们利用具有良好生物相容性的天然矿物埃洛石纳米管为载体,通过简单的化学反应将癌细胞靶向分子和磁性纳米粒子与之复合得到多功能复合纳米药物载体。阳离子抗癌药物与纳米管表面的负电性通过静电作用进行担载,该体系显示了pH响应的药物释放性能。同时由于超顺磁纳米粒子的存在,材料具备超顺磁性,在磁性靶向和磁共振成像(MRI)上有潜在的应用前景。我们期望这种精心设计的体系为制备靶向药物载体提供一种新的思路。更多还原

【Abstract】 Rapid advances in nanotechnology have provided new opportunities for a variety of disciplines. Nanostructured materials have emerged as novel bioimaging, diagnostic, and therapeutic agents for the future medical field. In the latest decades, the drug delivery system based on nanocarriers has attracted much attention. Nanocarriers can be used to increase local drug concentration by carrying the drug within and control-releasing it when bound to the targets, and then greatly enhancing the therapeutic index of the drugs. The family of nanocarriers includes polymer conjugates, polymeric nanoparticles, lipid-based carriers such as liposomes and micelles, dendrimers, carbon nanotubes, and inorganic nanoparticles etc. Among these nanoscopic therapeutic systems, silicon-based porous materials, have emerged as an innovative nanovectors for drug delivery due to their remarkable biocompatibility, biodcgradability, case of functionalization and many other fascinating features. In this thesis, we designed and prepared kinds of functionalized silicon-based porous materials as nanocarriers of drug delivery.In the last two decades, efforts have mainly been focused on the study of porous silica and metal-based compounds; however, porous silicon related materials are rarely investigated. In fact, porous silicon as one of the most important semiconductor has found the significant way in many fields such as microelectronics, photocatalysts, and biological/chemical sensing. In chapter two, we have demonstrated a strategy to prepare mesoporous silicon from parent mesoporous silica via magnesiothermic reduction. The resulted mesoporous silicon possesses uniquemesopores itself. Another feature of as-prepared mesoporous silicon is that they exhibit high surface area, high crystallinity and preserve the same morphology of mesoporous silica precursors. Besides, these materials may hold immense promise in drug delivery system and intrigue interest in studies of semiconductor. Moreover, the present strategy will provide an effective way to the targeted synthesis of mesoporous silicon-based materials for further applications.The mesoporous silica have been promising in many fields including catalysis, separation science and sensors due to their unique and advantageous structural properties, such as high surface area and pore volume, stable mesostructure, tunable pore diameter and modifiable morphology. And then this triggered widely research interest on the fabrication of mesoporous silica based drug delivery system as well. Recently, the development of gated stimuli-responsive drug delivery system based on mesoporous silica is a new research field. To date, different gated structures have been reported that contain, which in most of cases use pH, rcdox changes, and light as trigger for uncapping the pores. Out of these applied stimuli, a more effective strategy to accomplish fast-cytoplasmic drug release to cancer cells will be to employ pH responsive nanoparticles as drug vehicles due to the acidic extracellular and intracellular environment of cancer cells. In chapter three, acid-decomposable, luminescent ZnO quantum dots (QDs) have been employed to seal the nanopores of mesoporous silica nanoparticles (MSNs), loaded with antineoplastic drug doxorubicin (DOX), to inhibit the premature drug release. After being internalized into lysosomes of HeLa cells, these ZnO QD lids arc instantly dissolved and in turn the loaded DOX is readily released to the cytosols from the MSNs and resultantly kill the cancer cells. ZnO QDs not only act as a cap but also exhibits synergistic antitumor activity. We anticipate that these unprecedented nanoparticles may prove a significant step towards the development of a pH-sensitive drug delivery system to minimize the drug toxicity.Recently, multifunctional nanostructured materials that combinations of various different properties have been applied to multimodal imaging and simultaneous diagnosis and therapy. Halloysite nanotubes (HNTs), a type of aluminosilicate clay mineral, having a hollow tubular structure in the submicron range, are increasingly becoming the focus of investigations. Due to its biocompatibility and very low cytotoxicity as demonstrated in cell growth experiments, hence, HNTs qualified a promising candidate for nanomedicine. In chapter four, we devised a facile strategy to utilize multifunctional halloysitc nanotubes as nanovector for anticancer drug delivery. Tumor cell targeting molecules folic acid (FA, a nonimmunogenic receptor-specific ligand) and magnetic nanopartieles were tethered to the halloysite nanotubes via a facile EDC chemistry. Furthermore, this multifunctional nanoformulation exhibited pH-sensitive drug release behavior due to electrostatic interaction between the drug and HNTs. It is expected that this orchestrated system may provide a more effective tool for targeted cancer therapeutics.更多还原