Molecular imaging technologies, such as PET imaging, have evolved into powerful tools for tumor diagnosis. Radiolabeled dimeric molecular probes have emerged as a promising strategy in PET imaging due to their outstanding characteristics. IF7, a peptide targeting Anxa1 overexpressed in endothelial cells of various tumor blood vessels, serves as an excellent tumor-targeting agent. This research aims to prepare IF7 dimer and evaluate its imaging performance and biological characteristics. The biological properties of the tracer were evaluated through in vitro experiments using U87 cells. MicroPET imaging and biodistribution were also studied in tumor-bearing mice. MicroPET studies showed a high tumor uptake at 30 and 60 min post-injection with 4.09 ± 0.83%ID/g and 2.66 ± 0.55%ID/g, respectively. Co-injection of excess nonradiolabelled peptide significantly reduced tumor uptake at 30 min (0.33 ± 0.15%ID/g), confirming the tumor-targeting specificity of IF7 dimer. The IF7 dimer tracer demonstrated excellent imaging performance as a tumor-targeting molecular probe, indicating potential clinical applicability and offering new possibilities for future early tumor diagnosis.

Graphical abstract

中文翻译：

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评估 18F-AlF 标记的 IF7 二聚体作为小鼠肿瘤靶向 PET 成像的有前途的分子探针

分子成像技术，例如 PET 成像，已发展成为肿瘤诊断的强大工具。放射性标记二聚体分子探针由于其突出的特性，已成为 PET 成像中一种有前景的策略。 IF7是一种针对在多种肿瘤血管内皮细胞中过表达的Anxa1的肽，是一种优秀的肿瘤靶向剂。本研究旨在制备IF7二聚体并评价其成像性能和生物学特性。通过使用 U87 细胞的体外实验评估示踪剂的生物学特性。还在荷瘤小鼠中研究了 MicroPET 成像和生物分布。 MicroPET 研究显示注射后 30 分钟和 60 分钟肿瘤摄取量较高，分别为 4.09 ± 0.83%ID/g 和 2.66 ± 0.55%ID/g。共注射过量的非放射性标记肽在 30 分钟后显着降低肿瘤摄取 (0.33 ± 0.15%ID/g)，证实了 IF7 二聚体的肿瘤靶向特异性。 IF7二聚体示踪剂作为肿瘤靶向分子探针表现出优异的成像性能，具有潜在的临床应用价值，为未来肿瘤早期诊断提供了新的可能性。

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