The disclosure is related to a chemical structure, a preparation and an imaging method of a tumor imaging tracer, especially to a SPECT radionuclide-labeled trimeric cyclic RGD peptide:
99m
Tc-4P-RGD
3
, which functions as a ligand to be combined with integrin α
v
β
3
receptor in tumor for tumor imaging. The preparation includes linking HYNIC-OSu with 4P-RGD
3
to form HYNIC-4P-RGD
3
and then chelating HYNIC with
99m
Tc to create
99m
Tc-4P-RGD
3
. Animal biodistribution and imaging experiments reveal higher uptake in tumor and lower uptake in normal organs, therefore the disclosure can improve image quality, Through animal metabolic experiments, the original form of
99m
Tc-4P-RGD
3
can be still excreted without the evidence of further metabolites in urine and feces. According to the disclosure, the tumor imaging tracer
99m
Tc-4P-RGD; combined with the integrin α
v
β
3
solves the issue of high background uptake in normal organs, such that radio-labeled SPECT imaging tracers are more suitable for animal whole-body tumor evaluation.
该披露涉及
化学结构、制备和肿瘤显像示踪剂的成像方法,特别是一种
SPECT放射性同位素标记的三聚循环
RGD肽:99mTc-4P-RGD3,其作为
配体与肿瘤中的整合素αvβ3受体结合用于肿瘤显像。该制备包括将HYNIC-OSu与4P-RGD3连接形成HYNIC-4P-RGD3,然后螯合HYNIC与99mTc形成99mTc-4P-RGD3。动物
生物分布和成像实验证实在肿瘤中摄取更高,在正常器官中摄取较低,因此该披露可以提高图像质量。通过动物代谢实验,原始形式的99mTc-4P-RGD3仍可在尿液和粪便中排泄,没有进一步代谢物的证据。根据该披露,肿瘤显像示踪剂99mTc-4P-RGD3与整合素αvβ3结合解决了正常器官中高背景摄取的问题,使放射性标记的
SPECT成像示踪剂更适合用于动物全身肿瘤评估。