基于金属钆-儿茶酚构建的纳米影像探针在小鼠正常器官的双模态成像

目的  研究基于金属钆-儿茶酚构建的纳米影像探针（TA-Gd@RB）在小鼠体内正常器官的磁共振/荧光（MRI/FI）双模态成像。方法  首先将TA-Gd@RB在体外进行弛豫率的测定；其次选取正常KM小鼠20只，随机分为4组（5只/组）：第1组注射TAGd@RB，第2组注射DTPA-Gd，分别进行小鼠的肝、膀胱MRI扫描，将TA-Gd@RB组在体内的增强效果与DTPA-Gd进行对比；第3组再次注射TA-Gd@RB，第4组注射PBS，分别进行小鼠活体、离体荧光成像，观察TA-Gd@RB作为荧光材料的成像效果。结果  TA-Gd@RB弛豫率为6.94 mmol^-1s^-1，是临床DTPA-Gd弛豫率4.09 mmol^-1s^-1的1.7倍；同时，TA-Gd@RB较临床用DTPAGd在小鼠肝和膀胱有着更好的增强效果、较高的增强幅度以及长时间的强化持续窗口。荧光成像结果显示TA-Gd@RB在体内主要器官均取得良好荧光成像效果，且与MRI结果相符合。结论  TA-Gd@RB在体外有着较高的弛豫效能；TA-Gd@RB进行MRI和FI的体内、外成像效果均佳，具有优异的FI/MRI双模态成像性能。

Dual-modal imaging of nano-imaging probes based on metal gadolinium-catechol in mice

  Objective  To explore the magnetic resonance imaging/fluorescence imaging (MRI/FI) dual-modality imaging of normal mice organs by a nano-imaging probe (TA-Gd@RB) constructed based on metal gadolinium-catechol.  Methods  Firstly, the relaxation performance of TA-Gd@RB and DTPA-Gd in vitro was compared. Secondly, 20 normal KM mice were selected and randomly divided into four groups, with 5 in each group: one group was injected with TA-Gd@RB, and one group was injected with clinical DTPA-Gd, the liver and bladder of the mice were MRI scanned respectively. In addition, the other group was injected with TA-Gd@RB again, last group was injected with PBS, fluorescence imaging of mice in vivo and in vitro were performed respectively.  Results  The results of in vitro relaxation efficacy showed that the relaxation rate of TA-Gd@RB in the experimental group was 6.94 mmol-1s-1, which was 1.7 times that of the clinical DTPA-Gd relaxation rate of 4.09 mmol-1s-1. By analyzing the enhancement effect, amplitude and duration of liver and bladder in mice, TA-Gd@RB had better enhancement effect, higher enhancement amplitude and longer duration of enhancement than DTPA-Gd. Fluorescence imaging results showed that TA-Gd@RB had better fluorescence imaging results in major organs in the body, which were consistent with MRI results.  Conclusion  TA-Gd@RB have a high relaxation effect in vitro. TA-Gd@RB performs both MRI and FI in vivo and in vitro imaging, and has excellent FI/MRI dual-modal imaging performance.