[一种光磁探针钆-二乙三胺五乙酸-乙二胺-异硫氰酸荧光素在脑间质空间成像与分析中的应用]

[Application of anoptomagnetic probe Gd-DO3A-EA-FITC in imaging and analyzing the brain interstitial space].

作者信息

Li Y Q, Sheng Y, Liang L, Zhao Y, Li H Y, Bai N, Wang T, Yuan L, Han H B

机构信息

Department of Chemical Biology, Peking University School of Pharmaceutical Sciences, Beijng 100191, China; Peking University Medical and Health Analysis Center, Beijng 100191, China; Beijing Key Lab of Magnetic Resonance Imaging Device and Technique, Beijing 100191, China.

Department of Chemical Biology, Peking University School of Pharmaceutical Sciences, Beijng 100191, China.

出版信息

Beijing Da Xue Xue Bao Yi Xue Ban. 2018 Apr 18;50(2):221-225.

PMID:29643518

Abstract

OBJECTIVE

To investigate the application of the optical magnetic bimodal molecular probe Gd-DO3A-ethylthiouret-fluorescein isothiocyanate (Gd -DO3A-EA-FITC) in brain tissue imaging and brain interstitial space (ISS).

METHODS

In the study, 24 male SD rats were randomly divided into 3 groups, including magnetic probe group (n=6), optical probe group (n=6) and optical magnetic bimodal probe group (n=12), then the optical magnetic bimodal probe group was divided equally into magnetic probe subgroup (n=6) and optical probe subgroup (n=6). Referencing the brain stereotaxic atlas, the coronal globus pallidus as center level, the probes including gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA), fluorescein isothiocyanate (FITC) and Gd-DO3A-EA-FITC of 2 μL (10 mmol/L) were injected into the caudate nucleus respectively, magnetic resonance imaging (MRI) was performed in the magnetic probe group and magnetic probe subgroup to image the dynamic diffusion and distribution of the probes in the brain ISS, a self-developed brain ISS image processing system was used to measure the diffusion coefficient, clearance, volume fraction and half-time in these two groups. Laser scanning confocal microscope (LSCM) was performed in vitro in the optical probe group and optical probe subgroup for fluorescence imaging at the time points 2 hours after the injection of the probe, and the distribution in the oblique sagittal slice was compared with the result of the first two groups.

RESULTS

For the magnetic probe group and magnetic probe subgroup, there were the same imaging results between the probes of Gd-DTPA and Gd-DO3A-EA-FITC. The diffusion parameters of Gd-DTPA and Gd-DO3A-EA-FITC were as follows: the average diffusion coefficients [(3.31±0.11)×10 mm/s vs. (3.37±0.15)×10 mm/s, t=0.942, P=0.360], the clearance [(3.04±0.37) mmol/L vs. (2.90±0.51) mmol/L, t=0.640, P=0.531], the volume fractions (17.18%±0.14% vs. 17.31%±0.15%, t=1.961, P=0.068), the half-time [(86.58±3.31) min vs. (84.61±2.38) min, t=1.412, P=0.177], the diffusion areas [(23.25±0.68) mm vs. (22.71±1.00) mm, t=1.100, P=0.297]. The statistical analysis of each brain was made by t test, and the diffusion parameters were not statistically significant. Moreover, for the optical probe group and optical probe subgroup, the diffusion area of Gd-DO3A-EA-FITC [(22.61±1.16) mm] was slightly larger than that of FITC [(22.10±1.29) mm], the statistical analysis of each brain was made by t test, and the diffusion parameters were not statistically significant (t=0.713, P=0.492).

CONCLUSION

Gd-DO3A-EA-FITC shows the same imaging results as the traditional GD-DTPA, and it can be used in measuring brain ISS.

摘要

目的

探讨光磁双模态分子探针钆-二乙烯三胺五乙酸-乙基硫脲-异硫氰酸荧光素（Gd-DO3A-EA-FITC）在脑组织成像及脑间质间隙（ISS）中的应用。

方法

本研究中，24只雄性SD大鼠随机分为3组，包括磁探针组（n=6）、光探针组（n=6）和光磁双模态探针组（n=12），然后将光磁双模态探针组再平均分为磁探针亚组（n=6）和光探针亚组（n=6）。参照脑立体定位图谱，以冠状苍白球为中心层面，将2μL（10 mmol/L）的钆-二乙烯三胺五乙酸（Gd-DTPA）、异硫氰酸荧光素（FITC）和Gd-DO3A-EA-FITC探针分别注入尾状核，对磁探针组和磁探针亚组进行磁共振成像（MRI），以成像探针在脑ISS中的动态扩散和分布，使用自行研发的脑ISS图像处理系统测量这两组的扩散系数、清除率、体积分数和半衰期。对光探针组和光探针亚组在注射探针后2小时的时间点进行体外激光扫描共聚焦显微镜（LSCM）荧光成像，并将斜矢状切片中的分布与前两组结果进行比较。

结果

对于磁探针组和磁探针亚组，Gd-DTPA和Gd-DO3A-EA-FITC探针的成像结果相同。Gd-DTPA和Gd-DO3A-EA-FITC的扩散参数如下：平均扩散系数[（3.31±0.11）×10⁻⁹mm²/s对（3.37±0.15）×10⁻⁹mm²/s，t=0.942，P=0.360]，清除率[（3.04±0.37）mmol/L对（2.90±0.51）mmol/L，t=0.640，P=0.531]；体积分数（17.18%±0.14%对17.31%±0.15%，t=1.961，P=0.068），半衰期[（86.58±3.31）min对（84.61±2.38）min，t=1.412，P=0.177]，扩散面积[（23.25±0.68）mm²对（22.71±1.00）mm²，t=1.100，P=0.297]。对每个脑进行t检验统计分析，扩散参数无统计学意义。此外，对于光探针组和光探针亚组，Gd-DO3A-EA-FITC的扩散面积[（22.61±1.16）mm²]略大于FITC的扩散面积[（22.10±1.29）mm²]，对每个脑进行t检验统计分析，扩散参数无统计学意义（t=0.713，P=0.492）。