本文關(guān)鍵詞：UCNPs核殼結(jié)構(gòu)的合成與多模生物成像　出處：《湘潭大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 活體生物成像 稀土上轉(zhuǎn)換 造影劑 核殼結(jié)構(gòu)

【摘要】：稀土上轉(zhuǎn)換納米材料(UCNPs)由于其獨(dú)特的發(fā)光性質(zhì)在生物熒光成像領(lǐng)域有著很好的應(yīng)用前景,而且還可以作為藥物載體通過靶向作用到達(dá)病理位置并進(jìn)行可視化監(jiān)控。除了在熒光(UCL)成像方面,UCNPs還可以用作其它成像技術(shù)(如計(jì)算機(jī)斷層掃描(CT)、磁共振(MRI)等)的探針,但是其組織穿透深度低、發(fā)光效率不夠高等缺陷限制了其發(fā)展腳步。如何制備出穿透深度高、發(fā)光效率高、分散性好、形貌尺寸可控的多模式生物成像探針成為關(guān)鍵問題。因此,針對這些關(guān)鍵問題,本文的主要研究內(nèi)容分為以下主要兩個方面:(1)在油酸(OA)/十八烯(ODE)/油銨(OM)的反應(yīng)體系中通過熱分解法合成了一系列形貌均一、尺寸均勻、分散性非常好的超細(xì)Tm3+和Er3+分別摻雜的NaYbF4納米晶,同時又在OA/ODE的體系中通過熱分解法在其表面包覆一層NaGdF4納米晶,得到了Tm3+和Er3+分別摻雜的NaYF4@NaGdF4核殼結(jié)構(gòu)的納米晶。首先通過透射電鏡(TEM)和高分辨透射電鏡(HRTEM)對其形貌、尺寸和結(jié)構(gòu)進(jìn)行表征,通過X射線粉末衍射(XRD)確認(rèn)了其立方相的結(jié)構(gòu),從場發(fā)射透射電鏡得到的先掃描圖中可以看出納米材料的這種核殼結(jié)構(gòu)。在980 nm激光激發(fā)下,NaYbF4:Tm及NaYbF4:Tm@NaGdF4在800 nm處發(fā)射較強(qiáng)的近紅外光及較弱的藍(lán)光和紅光,由于人眼對藍(lán)光比較敏感,所以,當(dāng)分散在溶液中時,肉眼觀察到的是藍(lán)光。在980 nm激光激發(fā)下,Na YbF4:Er與Na YbF4:Er@NaGdF4納米顆粒的上轉(zhuǎn)換光譜呈現(xiàn)出較高的紅綠比,激光照射下肉眼看到的顏色為橙色。(2)對以上合成的納米材料進(jìn)行水相改性,并接上生物相容性比較好的檸檬酸配體,通過傅里葉紅外光譜分析(FTIR)、熱重分析(TGA)、動態(tài)光散射(DLS)和Zeta電位等分析方法對改性后的親水性納米材料進(jìn)行表征。酶聯(lián)免疫檢測儀(MTT實(shí)驗(yàn))測試了材料對細(xì)胞沒有明顯的毒性,另外,經(jīng)蘇木精和伊紅染色后,光學(xué)顯微鏡下觀察到納米材料對生物組織沒有毒性。將這種接有配體的材料通過尾靜脈注射入小鼠體內(nèi),可以觀察到來自肝和脾的信號,而其他器官則沒有信號,可以說明,Cit-NaYbF4:Tm@NaGdF4主要分布在小鼠的肝脾部位。沒有接檸檬酸配體的NaYbF4:Er@NaGdF4裸粒子15分鐘后則主要富集在肝臟之處以及皮下肌肉組織中,沒有進(jìn)入脾臟。這種多功能性的納米探針不僅可以作為細(xì)胞和小動物活體UCL成像,還可以作為CT和MRI成像造影劑,成功的實(shí)現(xiàn)了UCL/CT/MRI多模生物成像。
[Abstract]:Due to its unique luminescence properties, UCNPshas a good application prospect in the field of bioluminescence imaging. It can also be used as a drug carrier to reach the pathological location through targeted action and to carry out visual monitoring, except for the imaging of fluorescent UCLs. UCNPs can also be used as a probe for other imaging techniques, such as computed tomography (CT), magnetic resonance imaging (MRI), etc., but its tissue penetration depth is low. The defects such as low luminescence efficiency restrict its development. Therefore, it is a key problem to prepare multi-mode biometric imaging probes with high penetration depth, high luminescence efficiency, good dispersion and controllable morphology and size. To address these key issues. The main contents of this paper are as follows: 1) A series of morphologies have been synthesized by thermal decomposition in the system of oleic acid / 18 oleic acid / oleic acid. Ultrafine Tm3 and Er3 doped NaYbF4 nanocrystals with uniform size and good dispersion. At the same time, a layer of NaGdF4 nanocrystalline was coated on the surface of OA/ODE by thermal decomposition method. Nanocrystalline of NaYF4@NaGdF4 core-shell structure doped with Tm3 and Er3 were obtained. First, the nanocrystalline of NaYF4@NaGdF4 core-shell structure was obtained by transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM). On the morphology. The structure of cubic phase was confirmed by X-ray powder diffraction (XRD). The core-shell structure of the nanomaterials can be seen from the first scanning diagram obtained by the field emission transmission electron microscope (TEM) under the excitation of 980nm laser. NaYbF4:Tm and NaYbF4:Tm@NaGdF4 emit strong near infrared light and weak blue and red light at 800nm, because the human eyes are sensitive to blue light. When dispersed in the solution, blue light was observed in the naked eye under the excitation of a 980nm laser. The upconversion spectra of Na YbF4:Er and Na YbF4:Er@NaGdF4 nanoparticles showed a high red-green ratio. The color seen by the naked eye under laser irradiation is orange. 2) the synthesized nanomaterials were modified in aqueous phase and the citric acid ligands with good biocompatibility were added. Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). Dynamic light scattering (DLS) and Zeta potential were used to characterize the modified hydrophilic nanomaterials. In addition, after hematoxylin and eosin staining, it was observed under optical microscope that the nanomaterials were not toxic to biological tissue. The ligand was injected into mice via tail vein. Signals from the liver and spleen can be observed, while other organs have no signals, which can be explained. Cit-NaYbF4:Tm@NaGdF4 was mainly distributed in the liver and spleen of mice, and NaYbF4 without citric acid ligand. The Er@NaGdF4 naked particles were mainly concentrated in the liver and subcutaneous muscle tissue 15 minutes later. Not into the spleen. This versatile nano-probe can be used not only as a cell and small animal in vivo UCL imaging, but also as a CT and MRI imaging contrast agent. UCL/CT/MRI multimode biometric imaging is successfully realized.
【學(xué)位授予單位】：湘潭大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TB34

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