镓掺杂微纳生物材料的制备、性能与固态核磁共振结构研究
文献类型：学位论文
| 作者 | 杨明顺 |
| 文献子类 | 硕士 |
| 导师 | 任进军 |
| 关键词 | ACP 硝酸镓 ACP 抗菌作用 gallium nitrate NaScF4 antibacterial effec 上转换发光 NaScF4 固态核磁共振 upconversion luminescence solid state NMR |
| 其他题名 | Gallium-doped micro-/nano- bio-materials: Preparation, properties and solid state NMR structure study |
| 英文摘要 | 硝酸镓已经成为可用于治疗和预防局部感染的新一代抗菌剂。而且镓（Ga3+）离子具有明显的抗癌作用，并被FDA批准用于治疗恶性肿瘤晚期骨转移引起的高血钙症。因此，硝酸镓的抗癌杀菌作用，受到了人们的广泛关注。然而，硝酸镓的生物利用率很低，需要长期并且持续的静脉给药。过量的Ga3+ 离子会引起腹泻、恶心、低血钙、肾毒性等毒副作用，限制了其在生物医疗领域的应用。 因此，我们利用溶胶-凝胶法以镓离子作为抗菌元素，具有优异生物活性的无定形磷酸钙（ACP）为载体，制备出具有抗菌、生物矿化和潜在的抗癌性能的复合材料。通过XRD和SEM对不同(Ga + Ca)/P摩尔比的镓掺杂的ACP的晶相、形貌和尺寸进行表征。通过体外降解实验和抗菌测试发现，Ga3+ 离子掺入ACP中，可以实现镓离子的持续释放，可以有效地杀灭铜绿甲胞杆菌并能长时间起到杀菌作用。利用固态核磁共振技术（NMR）研究镓掺杂ACP纳米材料的局部结构。通过31P 、71Ga单共振和31P{71Ga} REAPDOR测试发现，镓掺杂的ACP是由非晶态的 Gax(OH)yOz和磷酸钙团簇组成的。31P-CT-DRENAR测试结果表明所有样品中P只有一种类型Q0。 稀土掺杂的上转换发光纳米材料由于其在太阳能、生物标记、生物成像、红外显示、防伪领域的广泛应用而受到人们的广泛关注。在过去的几十年，Yb/ Er (Tm)共掺杂的MREF4 (M = Li, Na和K, RE = Y, La–Lu)上转换纳米材料的晶体结构、形貌及发光性能得到了系统性的研究。Sc作为一种重要的稀土元素，与其它稀土元素（Y， La-Lu）相比，Sc具有独特的电子结构和更小的原子半径。因此，以Sc为基质的上转换发光材料可能有独特的光学性能。然而，在近几年以Sc为基质的上转换发光材料的才得到人们的关注。迄今为止，人们已经利用不同的合成方法成功的制备了以Sc为基质的上转换纳米材料NaxScF3+x,并研究了六方相NaScF4的晶体结构。但是，掺杂离子（Yb3+，Er3+）所处的局部环境仍不清楚。 本文中，我们利用水热法制备了水溶性的六方相NaScF4:Yb/Er晶体。通过XRD、SEM对不同Yb3+ 掺杂浓度的NaScF4:Yb/Er样品的晶相、形貌和尺寸进行表征。在980nm激发光下，研究了NaScF4:xYb/2%Er （x = 4%~20%）微晶样品上转换发光特性。荧光测试表明，R/G比可以通过改变Yb3+ 掺杂浓度控制，并且在低Yb3+ 掺杂含量下可以获得强烈的红光。利用多种固态核磁共振技术对掺杂离子（Yb3+，Er3+）所处的局部环境进行解析。23Na、45Sc、19F 单共振和 19F{23Na} 和 19F{45Sc}REDOR测试表明，掺入NaScF4晶体中的Yb3+/Er3+离子优先取代的不是等价Sc3+ 离子的位置，而是Na+ 离子的位置。在以上研究的基础上，将Ga3+离子掺入NaScF4晶体中，研究了其上转换发光性能。通过先进的固态NMR技术研究材料的局部结构，提供了一种研究这类材料的新方法。; Gallium nitrate has recently emerged as a new generation antibacterial agent that may be useful in treating and preventing localized infections. Moreover, gallium ion has obvious anticancer effect and approved by FDA to treat hypercalcemia of malignancy caused by advanced bone metastasis of malignant tumor. Therefore, the anticancer and antibacterial effects of gallium nitrate have been widely concerned. However, gallium nitrate has low bioavailability that requires long-term intravenous injection. Excessive amounts of Ga3+ could lead to a series of side effects, such as diarrhea, nausea, hypocalcemia, renal toxicity and so on, which limits the application of gallium nitrate in biomedical field. Therefore, gallium ions as antibacterial element and ACP with high bioactivity as carrier were devised to develop a novel antibacterial, biological mineralization gallium-doped ACP complex material. The Ga-doped ACP nanoparticles with potential anticancer properties were prepared using sol-gel method. The phase, morphology and size of the obtained samples with different (Ga + Ca)/P molar ratio were characterized by XRD and SEM. In vitro degradation experiment and antibacterial test show that gallium ions doped into ACP have sustained release properties, which are effective in killing Pseudomonas aeruginosa and have a long-term antibacterial effect. The local structures of these gallium-doped ACP nano-materials were studied by solid state NMR techniques. It was found that gallium-doped ACP nanoparticles should be consisted of amorphous Gax(OH)yOz and calcium phosphate clusters by 31P, 71Ga single resonance and 31P{71Ga} REAPDOR tests. 31P-CT-DRENAR tests show that the phosphorus units of these samples are all Q0 species. Rare-earth doped upconversion (UC) fluorescence materials have been of significant interest, owing to their promising use in solar energy, bioimaging, fluorescent biolabels, displays and anti-counterfeiting field. In past decades, Yb/Er (Tm) co-doped MREF4 (M = Li, Na and K, RE = Y, La–Lu) UC nanocrystals (NCs) showing various crystal structure, morphology as well as UC luminescence have been systematically investigated. Sc as an important rare-earth element has a unique electronic structure and a smaller atomic radius compared with other rare-earth elements (Y, La-Lu). Thus, Sc-based UC nano-materials may produce optical properties different from those of other RE (Y, La-Lu) based NCs. However, Sc-based hosts have got some attention just in the last several years. Hitherto, Sc-based NaxScF3+x UCNCs have been successfully prepared using different synthesis methods. The crystal structure of the hexagonal NaScF4 has been studied. But the local environments of dopant ions (Yb3+, Er3+) are still unclear. We synthesized water-soluble hexagonal NaScF4:Yb/Er crystals via a facile hydrothermal method in the paper. The phase, morphology and size of the obtained samples with different concentrations of Yb3+ ions were characterized by XRD and SEM. The UC photoluminescence properties of NaScF4:xYb/2%Er (x = 4%~20%) microcrystals were characterized under 980 nm laser excitation. Fluorescence studies show the R/G ratio can be controlled by changing the Yb3+ doping concentration and intensive red luminescence can be obtained at lower Yb3+ concentration. The local environments of dopant ions (Yb3+, Er3+) in NaScF4 microcrystals were studied using multiple solid state NMR techniques. The 23Na, 45Sc, 19F single pulse and 19F{23Na} and 19F{45Sc} rotational echo double resonance (REDOR) tests proved that the dopant rare earth ions (Yb3+, Er3+) preferred to substitute Na+ rather than equivalent Sc3+ ions. Based on the above study, Ga3+ ions were incorporated into the NaScF4 crystals, and the upconversion luminescence properties were studied. The local structure studies through the multiple advanced solid state NMR techniques here provide a novel way to study this kind of materials. |
| 学科主题 | 光学工程 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/30929]  |
| 专题 | 中国科学院上海光学精密机械研究所 |
| 作者单位 | 中国科学院上海光学精密机械研究所 |
| 推荐引用方式 GB/T 7714 | 杨明顺. 镓掺杂微纳生物材料的制备、性能与固态核磁共振结构研究[D]. |
入库方式： OAI收割
来源：上海光学精密机械研究所
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