^(131)Ⅰ标记血管靶向分子在肿瘤显像中的应用

Evaluation of Tumor Vascular Targeting Agents Labelled with ^(131)Ⅰ in Imaging of Tumor

目的研究131Ⅰ标记的血管靶向分子(RGD10、F56、K237)的生物活性及在肿瘤部位的浓聚情况。方法采用Iodogen法标记血管靶向分子,用Sep-PakC18柱纯化,通过HUVEC检测它们的免疫活性分数和亲和常数,用手持式γ相机检测和比较它们在荷A549肺腺癌裸鼠肿瘤部位的浓聚情况。结果131I-RGD10、131Ⅰ-F56、131I-K237的免疫活性分数(IRF)分别为42.7%、55.1%和44.5%,与HUVEC的亲和常数Ka值分别为9.41×107L/mol、3.87×107L/mol和5.98×107L/mol。3个131Ⅰ标记的血管靶向分子中,131I-RGD10在肿瘤部位的浓聚效果更为明显。结论静脉注射131I-RGD10在肿瘤部位聚集,可望成为肿瘤早期核素显像诊断靶向分子。

Objective To investigate the biological activity of tumor vascular targeting agents（RGD10,F56 and K237） labelled with ^131Ⅰ and their specific localization in tumor. Methods Tumor vascular targeting agents were labelled with Iodogen method and subsequently separated with Sep-Pak C18 column. Then, their immunoreactive fraction and affinity constancc were determined after HUVECs trials. Their specific localization in nude mice bearing human A549 lung adenocarcinoma were observed and compared by eZscope. Results The immunoreactive fraction of ^131Ⅰ-RGD10 ^131Ⅰ-F56 and ^131Ⅰ-K237 was 42. 7%,55. 1% and 44. 5 %, respectively. Their affinity constant with HUVEC was 9. 41 ~ 107 L/mol,3. 87 ~ 107 L/mol and 5.98 ~ 107 L/mol, respectively. ^131Ⅰ- RGD10 located in tumor more densely than ^131Ⅰ-F56 and ^131Ⅰ- K237 after they were injected into the tail vein of nude mice. Conclusion ^131Ⅰ-RGD10 may be a targeting agent in radionuclide imaging of tumor early diagnosis.