Lu Jing-Jing, Wang Fang, Jin Zheng-Yu, Zhong Ding-Rong
Department of Radiology, PUMC Hospital, CAMS and PUMC, Beijing 100730, China.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao. 2009 Apr;31(2):124-8.
To investigate the feasibility of in vivo tumor detection using magnetic resonance (MR) molecular imaging with targeted magnetic nanoparticles as imaging probe.
Targeted probe was synthesized by covalently linking the recombinant human gonadotropin releasing hormone analog (the targeting portion) with the ultrasmall superparamagnetic iron oxide nanoparticles (the imaging portion). The imaging portion served as the control material. The in vitro tumor cell experiment and the in vivo experiment using nude mice bearing tumors were carried out to test the targeting ability of the probe. In the in vitro experiment, the targeting probe and control materials were incubated separately with A549 cells which had high affinity to gonadotropin releasing hormone. Then the cells were taken out and lysed. The resultant solution was then subjected to MR imaging. The T2 value of the solutions was measured and compared. In the in vivo experiment, the targeting probe was administered into nude mice bearing A549 tumors. Dynamic MR imaging was carried out to measure the signal and T2 value of the tumor. The control material was also administered into control group of nude mice, and dynamic magnetic resonance imaging was performed. The T2 value of the tumor in both groups were recorded and compared.
Both the in vitro and in vivo experiments proved the targeting ability of targeted probe. Compared with control material, the targeting probe had higher combining ability with tumor cells.
MR molecular imaging of tumor can be realized by using targeting magnetic nanoparticles.
探讨以靶向磁性纳米颗粒作为成像探针，利用磁共振（MR）分子成像进行体内肿瘤检测的可行性。
通过将重组人促性腺激素释放激素类似物（靶向部分）与超小超顺磁性氧化铁纳米颗粒（成像部分）共价连接来合成靶向探针。成像部分用作对照材料。进行体外肿瘤细胞实验以及使用荷瘤裸鼠的体内实验，以测试探针的靶向能力。在体外实验中，将靶向探针和对照材料分别与对促性腺激素释放激素具有高亲和力的A549细胞孵育。然后取出细胞并进行裂解。对所得溶液进行MR成像。测量并比较溶液的T2值。在体内实验中，将靶向探针注射到荷A549肿瘤的裸鼠体内。进行动态MR成像以测量肿瘤的信号和T2值。将对照材料也注射到对照裸鼠组中，并进行动态磁共振成像。记录并比较两组中肿瘤的T2值。
体外和体内实验均证实了靶向探针的靶向能力。与对照材料相比，靶向探针与肿瘤细胞具有更高的结合能力。
使用靶向磁性纳米颗粒可实现肿瘤的MR分子成像。
