^(99)Tc^m标记多肽VEGF125-136及其生物学分布

Radiolabelling VEGF125-136 with ^(99)Tc^m and their biodistribution in mice

目的探讨一种理想的99Tcm标记小分子多肽VEGF125-136的方法,并研究标记物的生物学分布。方法在合成多肽的过程中直接完成多肽VEGF125-136与双功能螯合剂MAG3的偶联,然后采用正交设计探讨99Tcm的最佳标记条件,并研究标记物稳定性和小鼠体内分布。结果①简化了偶联步骤,提高了偶联产率;②最佳标记条件下标记率约78%,经HPLC纯化后放化纯度>95%,且在室温条件下稳定性好;③99mTc-VEGF125-136-MAG3在正常小鼠的血液中清除较快,在肾、肝中摄取较高。结论以MAG3为螯合剂用99Tcm标记VEGF125-136有良好的标记率。

Objective To explore a better method for radiolabelling VEGF125-136 with 99Tcm and investigate the biodistribution of radiolabeled VEGF125-136 in mice. Methods Chelant MAG3 was directly conjugated with VEGF125-136 during the synthesis of VEGF125-136. The best labelling conditions of^99Tc^m, stability in vitro and biodistribution in normal mice of ^99Tc^m-VEGF125-136-MAG3 were investigated. Results The couple method between MAG3 and VEGF125-136 was simplified and couple efficiency was raised. VEGF125-136 was successfully radiolabeled by ^99Tc^m, and the average labelling efficiency reached 78%. Being purified by HPLC, the radiochemical purity of ^99Tc^m-VEGF125-136-MAG3 was higher than 95% , and ^99Tc^m-VEGF125- 136-MAG3 was stable in vitro at room temperature. The biodistribution study of^99Tc^m-VEGF125-136-MAG3 in normal mice showed that there was a high uptake in kidney and liver, and can be cleared quickly from blood. Conclusion These strategies for coupling and labelling VEGF125-136 and MAG3 are simple and efficient. ^99Tc^m-VEGF125-136-MAG3 is stable in vitro and appears to be suitable for further experiments and clinic applications in future.