中文摘要：

目的利用合成模块，建立^68Ga标记合成PSMA抑制剂PSMA-11的新方法，研究其生物分布及代谢动力学特征。方法向4 ml含185～555 MBq GaCl3溶液中加入5 μg PSMA-11，调节pH值至4.0，常温或90 ℃反应10 min，HPLC检测其放化纯、产率，评价^68Ga-PSMA-11的体外稳定性。利用22RV1和PC-3细胞考察肿瘤细胞与其结合能力。MicroPET/CT动态显像及解剖观察^68Ga-PSMA-11在正常小鼠及荷瘤鼠体内的生物分布。勾画ROI，获得血液、肿瘤和各主要脏器的TAC，并考察其在血液中的代谢动力学特点。结果常温或90 ℃反应条件下，产物放化纯均在99%以上；90 ℃加热时未校正的产率为（95±2）%，高于常温时的（89±3）%。PSMA阳性的22RV1细胞对该标记化合物的摄取明显高于PSMA阴性的PC-3细胞。^68Ga-PSMA-11血液清除快，主要经肾脏排泄，肠道有部分放射性摄取，肝脏和肺放射性摄取少。MicroPET/CT显像示，^68Ga-PSMA-11对PSMA阳性肿瘤有很好的靶向性。加热条件下清除半衰期更短。结论^68Ga-PSMA-11的生物分布理想、血液清除快，主要经肾脏排泄，小肠、肝、肺放射性摄取很少，清除很快，是优良的PSMA靶向显像剂。加热条件下制备的^68Ga-PSMA-11产率更高、血液清除更快。

英文摘要：

Objective To synthesize ^68Ga-labeled PSMA inhibitor （^68Ga-PSMA-11） with semi-automated module and to evaluate its biodistribution and kinetics in normal mice.Methods A total of 5 μg PSMA-11 was added into 4 ml GaCl3 elute （185-555 MBq）, and the pH value was adjusted to 4.0. The mixture was reacted at room temperature （RT） or 90 ℃ for 10 min. The radiochemical purity and yield were analyzed by HPLC, and its stability in vitro was evaluated. Cell uptake was detected on 22RV1 and PC-3 cells. The biodistribution and kinetics were evaluated by the dissection method and dynamic imaging with microPET/CT in normal and tumor-bearing mice. ROI analysis was performed, TAC was processed in main organs.Results The radiochemical purity of ^68Ga-PSMA-11 was higher than 99%. The radio-yield was （95±2）% in module（90 ℃）, whereas （89±3）% at RT. The uptake of ^68Ga-PSMA-11 by PSMA-positive 22RV1 cells was significantly higher than that of PSMA-negative PC-3 cells. ^68Ga-PSMA-11 in blood was cleared rapidly, it was mainly excreted by the kidneys. Some radioactive uptake was found in the liver and intestine; and less radioactive uptake in lungs. MicroPET/CT imaging showed that ^68Ga-PSMA-11 had a good affinity to PSMA-positive tumors. Further study showed that Tβ1/2 was shorter when ^68Ga-PSMA-11 was labeled at 90 ℃. Conclusions 68Ga-PSMA-11 could present good biodistribution and rapid blood clearance in mice, thus it could be a promising PSMA targeting imaging agent. ^68Ga-PSMA-11 labeled at 90 ℃ has higher yield and faster blood clearance.