Ma Wenhui, Wang Zhe, Yang Weidong, Ma Xiaowei, Kang Fei, Wang Jing
Department of Nuclear Medicine, Xijing Hospital, Fourth Military Medical University, No. 127 West Changle Road, Xi'an, Shaanxi Province 710032, China.
Biomed Res Int. 2014;2014:618096. doi: 10.1155/2014/618096. Epub 2014 May 19.
A peptide containing Asn-Gly-Arg(NGR) sequence was synthesized and directly labeled with (99m)Tc. Its radiochemical characteristics, biodistribution, and SPECT imaging were evaluated in nude mice bearing human HepG2 hepatoma. Nude mice bearing HepG2 were randomly divided into 5 groups with 5 mice in each group and injected with ~7.4 MBq (99m)Tc-NGR. The SPECT images were acquired in 1, 4, 8, and 12 h postinjection via caudal vein. The metabolism of tracers was determined in major organs at different time points, which demonstrated rapid, significant tumor uptake and slow tumor washout. The control group mice were blocked by coinjecting unlabelled NGR (20 mg/kg). Tumor uptake was (2.52 ± 0.83%) ID/g at 1 h, with the highest uptake of (3.26 ± 0.63%) ID/g at 8 h. In comparison, the uptake of the blocked control group was (1.65 ± 0.61%) ID/g at 1 h after injection. The SPECT static images and the tumor/muscle (T/NT) value were obtained. The highest T/NT value was 7.58 ± 1.92 at 8 h. The xenografted tumor became visible at 1 h and the clearest image of the tumor was observed at 8 h. In conclusion, (99m)Tc-NGR can be efficiently prepared and it exhibited good properties for the potential SPECT imaging agent of tumor.
合成了一种含有天冬酰胺-甘氨酸-精氨酸（NGR）序列的肽，并直接用（99m）Tc进行标记。在荷人HepG2肝癌的裸鼠中评估了其放射化学特性、生物分布及单光子发射计算机断层显像（SPECT）成像。将荷HepG2的裸鼠随机分为5组，每组5只，注射约7.4 MBq的（99m）Tc-NGR。在注射后1、4、8和12小时经尾静脉采集SPECT图像。在不同时间点测定主要器官中示踪剂的代谢情况，结果显示肿瘤摄取迅速且显著，肿瘤清除缓慢。对照组小鼠通过同时注射未标记的NGR（20 mg/kg）进行阻断。肿瘤摄取在1小时时为（2.52±0.83）% ID/g，在8小时时摄取最高，为（3.26±0.63）% ID/g。相比之下，阻断对照组在注射后1小时的摄取为（1.65±0.61）% ID/g。获得了SPECT静态图像和肿瘤/肌肉（T/NT）值。在8小时时最高T/NT值为7.58±1.92。移植瘤在1小时时可见，在8小时时观察到最清晰的肿瘤图像。总之，（99m）Tc-NGR能够高效制备，并且作为潜在的肿瘤SPECT显像剂表现出良好的特性。
