This invention is related to the synthetic method of a 99mTc-labeled trimeric cyclic RGD peptide (99mTc-4P-RGD3) tumor imaging tracer. This tracer functions as a ligand to be combined with integrin αvβ3 receptor in tumor for the purpose of tumor imaging. The synthetic process includes a step of linking HYNIC-Osu with 4P-RGD3 to form HYNIC-4P-RGD3 and then chelate HYNIC with 99mTc isotope to create 99mTc-4P-RGD3. Animal biodistribution and imaging experiments reveal higher uptake in tumor (target) and lower uptake (background) in normal organs, therefore capable of improving image quality as the advantage. Through the animal metabolic experiment, the original form of 99mTc-4P-RGD3 can be still excreted without the evidence of further metabolites in urine and feces. The invention of 99mTc-4P-RGD3 as an integrin αvβ3 tumor imaging tracer solves the issue of high background uptake in normal organs to make the type of Tc99m-labeled imaging tracers more suitable for animal whole-body tumor evaluation.本發明是關於一種腫瘤顯像藥劑的化學結構及製備方法,特別是關於一項SPECT鎝(99mTc)標記RGD環肽三聚體藥物:99mTc-4P-RGD3,此腫瘤顯像藥物以配體方式與整合素αvβ3受體結合,而達到腫瘤部位顯像的用途。實施步驟包括:將HYNIC-Osu與4P-RGD3進行連接步驟以獲得配體HYNIC-4P-RGD3、利用配體中的HYNIC和99mTc螯合作用步驟製成99mTc-4P-RGD3腫瘤顯像藥物、通過動物體內分布研究及腫瘤顯像步驟證實較高的腫瘤攝取及更低的全身正常臟器本底攝取,可提高全身腫瘤圖像的清晰度、通過藥物代謝實驗步驟顯示99mTc-4P-RGD3經過動物體內代謝後仍可由原型方式排出體外。經本發明所采用的技術手段所製備的鎝標記整合素αvβ3腫瘤顯像藥劑(99mTc-4P-RGD3),解決了其他鎝標記RGD藥物在動物體內所產生的高本底攝取問題,使鎝標記RGD藥物更適用於全身腫瘤的評估。
