靶向核磁造影剂Gd-DOTA-E-[c(RGDfK)]_2的制备及性能研究

Preparation and Performance Research of Target NMR Contrast Agent Gd-DOTA-E-[c( RGDfK)]_2

目的制备Gd-DOTA-E-[c(RGDfK)]_2靶向造影剂,并对其弛豫性能、细胞毒性以及靶向性进行评价。方法采用F-moc固相法合成靶向双环肽E-[c(RGDfK)]_2,与螯合剂1,4,7,10-四氮环十二烷基-1,4,7,10-四乙酸(DOTA)共价连接,利用配位键螯合Gd^(3+),制备核磁共振成像(MRI)造影剂Gd-DOTA-E-[c(RGDfK)]_2。并用质谱仪(ESI-MS)、核磁共振仪(NMR)对其结构进行表征,通过弛豫性能、四甲基偶氮唑蓝法(MTT)、小鼠MRI造影实验对其性能进行评价。结果ESI-MS、NMR结果表明,Gd-DOTA-E-[c(RGDfK)]_2合成成功,弛豫效率(k=9.551 mmol^(-1)·L·s^(-1))是商用造影剂钆特酸葡胺注射液(GdDOTA)的1.84倍;MTT实验结果显示,Gd-DOTA-E-[c(RGDfK)]_2的细胞毒性低于Gd-DOTA;小鼠MRI造影实验结果显示,Gd-DOTA-E-[c(RGDfK)]_2具有靶向性并成像清晰。结论Gd-DOTA-E-[c(RGDfK)]_2是一种在生物体内稳定性好,细胞毒性低,并有靶向性能的MRI造影剂,具有研究和应用价值。

OBJECTIVE To prepare Gd-DOTA-E-[ c （RGDfK） ] 2 targeted contrast agent and evaluate its relaxation properties, cytotoxicity and targeting. METHODS E-[ c （RGDfK） ] 2 was synthesized by F-moc solid phase method, covalently bonded with che- lating agent DOTA, meanwhile ultilizing chelating ligand Gd3＋ to prepare MRI contrast agent Gd-DOTA-E-[ c （RGDfK） ] 2- The struc- ture was characterized by ESI-MS and NMR, and the properties were evaluated by relaxation properties, MTT and mouse MRI contrast assay. RESULTS ESI-MS and NMR results showed that Gd-DOTA-E-[ c（RGDfK） ] 2 was synthesized successfully, and its relaxation efficiency（k =9. 551 mmol^-1·L·s^-1 ） is 1.84 times more efficient than a commercially available contrast agent of Gd-DOTA; MTT results showed that the toxicity of Gd-DOTA-E-[ c （RGDfK） ] 2 cell is lower than that of Gd-DOTA; the experimental results in MRI angiography showed that Gd-DOTA-E-[ c（RGDfK） ] 2 is possessing of targeting and can image clearly. CONCLUSION Gd-DOTA-E- [ c （RGDfK） ] 2 is a kind of MRI contrast agent with good stability, low cytotoxicity and targeted properties in vivo,which is valuable in research and application.