Radiolabeled cyclic arginine-glycine-aspartic (RGD) peptides can be used for noninvasive determination of integrin αvβ3 expression in tumors. In this study, we performed radiosynthesis and biological evaluation of a new 18F-labeled RGD homodimeric peptide with one 8-amino-3,6-dioxaoctanoic acid (PEG2) linker on the glutamate β-amino group (18F-FP-PEG2-β-Glu-RGD2) as a symmetric PET tracer for tumor imaging. Biodistribution studies showed that radioactivity of 18F-FP-PEG2-β-Glu-RGD2 was rapidly cleared from blood by predominately renal excretion. MicroPET-CT imaging with 18F-FP-PEG2-β-Glu-RGD2 revealed high tumor contrast and low background in A549 human lung adenocarcinoma-bearing mouse models, PC-3 prostate cancer-bearing mouse models, and orthotopic transplanted C6 brain glioma models. 18F-FP-PEG2-β-Glu-RGD2 exhibited good stability in vitro and in vivo. The results suggest that this tracer is a potential PET tracer for tumor imaging.
放射性标记的环精
氨酸-甘
氨酸-
天冬氨酸(RGD)肽可用于无创检测肿瘤中整合素αvβ3的表达。在这项研究中,我们对一种新的 18F 标记 RGD 同源二聚体肽进行了放射合成和
生物学评估,该肽在谷
氨酸 β-
氨基上有一个 8-
氨基-3,6-二氧杂
辛酸(P
EG2)连接基(18F-FP-P
EG2-β-Glu-RGD2),是一种用于肿瘤成像的对称 PET 示踪剂。
生物分布研究表明,18F-FP-P
EG2-β-Glu-RGD2 的放射性会迅速从血液中清除,主要通过肾脏排泄。在 A549 人肺腺癌小鼠模型、PC-3 前列腺癌小鼠模型和正位移植 C6 脑胶质瘤模型中,18F-FP-P
EG2-β-Glu-RGD2 的 MicroPET-CT 成像显示肿瘤对比度高,背景低。18F-FP-P
EG2-β-Glu-RGD2 在体外和体内均表现出良好的稳定性。结果表明,该示踪剂是一种潜在的肿瘤成像 PET 示踪剂。