Abstract
在本研究中，以製備Gd(acac)TPP-cremophor micelles作為核磁共振為目的，此藥中所含之釓(Gd)為一順磁性金屬，其外圍4f軌域具有7個未對電子，能夠形成區域性的小磁場而縮短其周圍氫質子的縱向弛緩時間 (T1)以及橫向弛緩時間(T2)，以達到增進核磁共振影像訊號強度的目的． Gd(acac)TPP為一高度脂溶性之化合物，假如不以界面活性劑：Cremophor EL將其修飾成為水溶性而直接將此藥由靜脈注射，將造成藥物阻塞在肺臟，而無法達到造影的效果．本研究將Cremophor EL與Gd(acac)TPP經過超音波振盪形成水溶性的膠粒(micelle)結構．實驗結果顯示：所合成的 Gd(acac)TPP-cremophor micelles具有水溶性,高弛緩效率,體積小以及低毒性等性質．此藥經由靜脈注射後，其主要靶器官為肝臟及脾臟，並且大部份由肝臟及腎臟所代謝．在藥物注入24 小時後，正常肝臟與肝腫瘤的藥物滯留量比值為2.1；而皮下腫瘤與藥物的滯留量比值為2.5．無論是在具有肝腫瘤的大白鼠或是皮下腫瘤的小白鼠，其於核磁共振造影兩者皆得腫瘤與其周圍正常組織清晰的對比影像．In this study, we synthesized Gd-acetylacetone-tetraphenyl-porphyrin(GdacacTPP)-cremophor micelles as the nuclearmagnetic resonance image(MRI) contrast agent. Gd can reduceT1 and T2 values of protons around it, and increase the signalintensity. Gd(acac)TPP is a highly hydrophobic compound,it would be accumulated in lung if directly injected through vein without the modification of the surfactant :Cremophor EL. The The Cremophor EL is sonicated with Gd(acac)TPP to form a hydrophilic "micelle" structure. Theresults show that Gd(acac)- TPP-cremophor micelles is water-soluble,high proton relaxivity,small particle size and lowtoxicity. The target organs are liver and spleen. This drug ismetabolizied mainly by liver and kidney. The drug retentionratio 24 hrs after injection in Normal liver and hepatoma is2.1 ; in sarcoma and muscle is 2.5 accordingly. Clearcontrast images of tumors are obtained in hepatoma-bearingrats and sarcoma-bearing mice.