Platelet-derived growth factor receptor β (PDGFRβ) is a transmembrane tyrosine kinase receptor and it is upregulated in various malignant tumors. Radiolabeled PDGFRβ inhibitors can be a convenient tool for the imaging of tumors overexpressing PDGFRβ. In this study, [¹²⁵I]-1-{5-iodo-2-[5-(2-methoxyethoxy)-1H-benzo[d]imidazol-1-yl]quinoline-8-yl}piperidin-4-amine ([¹²⁵I]IIQP) and [¹²⁵I]-N-3-iodobenzoyl-1-{2-[5-(2-methoxyethoxy)-1H-benzo[d]imidazol-1-yl]quinolin-8-yl}-piperidin-4-amine ([¹²⁵I]IB-IQP) were designed and synthesized, and their potential as PDGFRβ imaging agents was evaluated. In cellular uptake experiments, [¹²⁵I]IIQP and [¹²⁵I]IB-IQP showed higher uptake by PDGFRβ-positive cells than by PDGFRβ-negative cells, and the uptake in PDGFRβ-positive cells was inhibited by co-culture with PDGFRβ ligands. The biodistribution of both radiotracers in normal mice exhibited hepatobiliary excretion as the main route. In mice inoculated with BxPC3-luc (PDGFRβ-positive), the tumor uptake of radioactivity at 1 h after the injection of [¹²⁵I]IIQP was significantly higher than that after the injection of [¹²⁵I]IB-IQP. These results indicated that [¹²⁵I]IIQP can be a suitable PDGFRβ imaging agent. However, further modification of its structure will be required to obtain a more appropriate PDGFRβ-targeted imaging agent with a higher signal/noise ratio.

血小板衍生的生长因子受体β（PDGFRβ）是跨膜酪氨酸激酶受体，在各种恶性肿瘤中均被上调。放射性标记的PDGFRβ抑制剂可以成为对过表达PDGFRβ的肿瘤进行成像的便捷工具。在这项研究中，[ ¹²⁵ I] -1- {5-碘-2- [5-（2-甲氧基乙氧基）-1 H-苯并[ d ]咪唑-1-基]喹啉-8-基}哌啶-4-胺（[ ¹²⁵ I] IIQP）和[ ¹²⁵ I] -N -3-碘苯甲酰基-1- {2- [5-（2-甲氧基乙氧基）-1 H-苯并[ d ]咪唑-1-基]喹啉-8 -yl} -piperidin-4-amine（[ ¹²⁵设计并合成了I] IB-IQP），并评估了其作为PDGFRβ显像剂的潜力。在细胞摄取实验中，[ ¹²⁵ I] IIQP和[ ¹²⁵ I] IB-IQP显示PDGFRβ阳性细胞的摄取高于PDGFRβ阴性细胞，并且与PDGFRβ配体共培养可抑制PDGFRβ阳性细胞的摄取。两种放射性示踪剂在正常小鼠中的生物分布均以肝胆汁排泄为主要途径。在接种了BxPC3-luc（PDGFRβ阳性）的小鼠中，注射[ ¹²⁵ I] IIQP后1 h的肿瘤吸收显着高于注射[ ¹²⁵ I] IB-IQP后的肿瘤。这些结果表明[ ¹²⁵I] IIQP可以是合适的PDGFRβ显像剂。然而，将需要对其结构进行进一步的修饰以获得具有较高信噪比的更合适的PDGFRβ-靶向的成像剂。