纳米CT造影剂的制备与影像学应用

发布时间：2018-06-08 18:26

本文选题：CT + 造影剂　；参考：《吉林大学》2014年博士论文

【摘要】：目的：合成一种新型纳米CT造影Yb(OH)CO3并对其样本进行表征。研究Yb(OH)CO3作为CT造影剂的毒性，同时研究该造影剂在小鼠体内分布和代谢情况。为其临床应用提供可行性依据。材料与方法：（1）纳米粒子Yb(OH)CO3的制备与表征：纳米粒子Yb(OH)CO3的制备是由一个以尿素为基础的均相沉淀过程。将Yb(NO3)3·5H2O(7.5mmol)和尿素(15g)溶解到去离子水中，并使溶液的总体积达到500ml。将上述溶液在室温条件下使用磁力搅拌器搅拌2小时使溶液达到均匀。然后，将所得的均匀溶液90℃油浴3小时。后将所得到的悬浮液通过离心分离，得到的产物为白色粉末，用纱布包好后放入索氏提取器中，先用去离子水洗3-4遍，再用乙醇清洗3-4遍后，在60℃恒温条件下真空烘箱中抽真空24小时，以备后续实验研究用。应用扫描电镜(SEM)、透射电镜(TEM)、X-射线衍射(XRD)分析对样本进行表征。（2）体外毒性实验：应用MTT方法进行体外细胞毒性实验，使用Bio-Radmodel-68酶标仪在570nm波长下测定吸光度值，分析细胞活力；将HepG2细胞制成单细胞悬液使用光学显微镜观察细胞态学变化；通过紫外可见光吸收光谱的方法进行体外溶血分析。（3）体内动物实验：随机选取12只小鼠分为2组，一组注射Yb(OH)CO3为实验组，另一组注射生理盐水为对照组。30天后将两组小鼠进行处死解剖进行组织学分析来确定Yb(OH)CO3对小鼠的体内毒性。（4）计算机断层摄影（CT）体外成像评价造影剂的效率：将不同浓度的纳米粒子Yb(OH)CO3稀释液和碘比醇稀释液分别加入到含有琼脂糖的PBS溶液中并使用飞利浦256层螺旋CT进行扫描，结果以EP管所成CT值计算。（5）体内评价CT影像：使用飞利浦256层螺旋CT进行扫描，通过多平面重组技术（MPR）将获得的原始薄层轴位图像建成所需要的冠状位图像。（6）造影剂的体内分布与代谢实验：将注射Yb(OH)CO3造影剂的小鼠在不同的时间点处死并提取主要器官以便定量分析镱（Yb）粒子，使用ICP-MS分析从小鼠身上获得的尿液和粪便提取样品。结果：（1）成功制备了纳米粒子Yb(OH)CO3并对其进行了形态和外貌的表征。从纳米粒子Yb(OH)CO3的扫描电子显微镜(SEM)图像中可以看到纳米粒子样品的表面光滑而且单个分散并呈大致相同的球形。（2）MTT实验表明在有纳米粒子存在的条件下培养48小时后仍然有91%以上的细胞能够存活。体外细胞形态学观察表面在有纳米粒子存在的条件下细胞的正常生长并没有受到影响。体外溶血分析实验表明在大剂量使用Yb(OH)CO3（1mg NPs/mL）的条件下几乎没有发生红细胞的溶血现象。（3）实验组和对照组中所有的小鼠均在饲养30天后均被处死并对其器官进行提取，没有观察到纳米粒子Yb(OH)CO3造成的组织损伤以及任何其他负性影响。（4）Yb(OH)CO3组小鼠在不同时间点处死后发现镱粒子主要聚集在网状内皮系统如肝脏和脾脏，其结果与CT影像一致。在注射造影剂1，3，5，7天后收集小鼠的尿液和粪便发现高浓度的镱粒子。（5）CT成像，随着Yb(OH)CO3和碘比醇浓度的增加CT值逐渐升高，CT值与造影剂的浓度呈现良好的线性关系。但在相同浓度条件下Yb(OH)CO3的射线吸收计量明显高于碘比醇的射线吸收计量。两组小鼠肝脏和肾脏平扫CT值均无统计学差异。在注射造影剂30分钟后，，Yb(OH)CO3组肝脏的CT值明显高于碘比醇组，而Yb(OH)CO3组肾脏的CT值明显低于碘比醇组具有显著的统计学意义。注射造影剂3分钟后碘比醇组的造影剂便大量聚集在肾脏，30分钟后几乎所有的造影剂都聚集于泌尿系统。时间延迟到2小时后Yb(OH)CO3组肝脏的CT值几乎是碘比醇组的3倍，而肾脏CT值与平扫时相比几乎没有变化。结论：（1）成功制备了低毒性、具有很好的组织相容性纳米CT造影剂Yb(OH)CO3。（2）Yb(OH)CO3体外CT成像、小鼠体内CT成像以及对小鼠尿液和粪便的研究，初步明确了其与传统造影剂碘比醇比较对组织影像的显示有明显的优势。
[Abstract]:Purpose :

A new type of nanometer CT angiography Yb ( OH ) CO3 was synthesized and its sample was characterized . The toxicity of Yb ( OH ) CO3 as CT contrast agent was studied , and the distribution and metabolism of the contrast agent in mice were studied .

Materials and Methods :

( 1 ) Preparation and characterization of nano - particle Yb ( OH ) CO3 : A homogeneous precipitation process based on urea was prepared by dissolving Yb ( NO3 ) 3 路 5H2O ( 7.5 mmol ) and urea ( 15 g ) in deionized water .

( 2 ) In vitro toxicity experiment : MTT assay was used for in vitro cytotoxicity test , and the absorbance value was measured at 570 nm using the Bio - Radmodel - 68 microplate reader , and the cell viability was analyzed ;
the HepG2 cells were made into a single cell suspension and the cell state change was observed by using an optical microscope ;
The in vitro hemolysis analysis was carried out by means of an ultraviolet visible light absorption spectrum .

( 3 ) In vivo animal experiment : 12 mice were randomly selected to be divided into 2 groups , one group was injected with Yb ( OH ) CO3 as the experimental group , and the other group received normal saline as the control group . After 30 days , two groups of mice were sacrificed and dissected to determine the toxicity of Yb ( OH ) CO3 to mice .

( 4 ) In vitro imaging of computed tomography ( CT ) : The efficiency of contrast agent was evaluated in vitro : different concentrations of nanoparticles Yb ( OH ) CO3 were added to PBS solution containing agarose and scanned by Philips 256 - layer spiral CT , and the results were calculated by the CT value of EP tube .

( 5 ) CT images were evaluated in vivo : 256 - slice spiral CT was used for scanning , and the obtained original thin - layer axial - bit image was built into the required coronal image by multi - plane reconstruction technique ( MPR ) .

( 6 ) In vivo distribution and metabolism experiment of contrast agent : mice injected with Yb ( OH ) CO3 contrast agent were sacrificed at different time points and the primary organs were extracted for quantitative analysis of ytterbium ( Yb ) particles , and urine and feces obtained from mice were analyzed using ICP - MS .

Results :

( 1 ) The nano - particle Yb ( OH ) CO3 was successfully prepared and characterized by morphology and appearance . The surface of the nano - particle sample can be seen to be smooth and spherical in the same spherical shape from the scanning electron microscope ( SEM ) image of the nano - particle Yb ( OH ) CO3 .

( 2 ) MTT assay showed that more than 91 % of the cells were able to survive in the presence of nanoparticles . The morphology of cells in vitro was not affected by the normal growth of cells in the presence of nanoparticles .

( 3 ) All the mice in the experimental group and the control group were sacrificed after 30 days of feeding and the organs were extracted , and no tissue damage caused by the nano - particle Yb ( OH ) CO3 and any other negative effects were observed .

( 4 ) Yb ( OH ) 3 group mice were sacrificed at different time points to find that ytterbium particles were mainly concentrated in reticuloendothelial system such as liver and spleen . The results were consistent with CT images . After 1 , 3 , 5 and 7 days injection of contrast agent , the urine and feces of mice were collected to find the high concentration ytterbium particles .

( 5 ) The CT value of Yb ( OH ) CO3 group was significantly higher than that of iodine - specific alcohol group . The CT value of Yb ( OH ) CO3 group was significantly higher than that of iodine - specific alcohol group . After 30 minutes of contrast agent , the CT value of the liver of Yb ( OH ) CO3 group was almost 3 times that of the group of iodine - specific alcohol , while the CT value of the kidney was almost unchanged compared with the time of plain scan .

Conclusion :

( 1 ) Low toxicity was successfully prepared , and a good tissue - compatible nano - CT contrast agent Yb ( OH ) CO3 was prepared .

( 2 ) In vitro CT imaging of Yb ( OH ) CO3 , CT imaging in mice and the study of urine and feces in mice , it is preliminarily clear that the comparison of iodine with traditional contrast agent has obvious advantages to the display of tissue images .
【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：R814

【参考文献】