Tilcock C P, Ahkong Q F, Parr M
Department of Radiology, University of British Columbia, Vancouver, Canada.
Invest Radiol. 1991 Mar;26(3):242-7. doi: 10.1097/00004424-199103000-00008.
We have developed an improved method for the production of liposomal gadolinium-DTPA (Gd-DTPA). The ionophore A23187 facilitates the uptake of externally added Gd into the interior aqueous space of a unilamellar lipid vesicle, where it is chelated by passively entrapped DTPA to form the Gd-DTPA chelate in situ. The presence of a pH gradient across the vesicle membrane is not essential for Gd uptake, the extent of which apparently is limited only by the interior concentration of the chelator. Once formed internally, the Gd-DTPA complex is retained within the vesicles for at least several days at room temperature. Biodistribution studies in mice indicate that liposomal Gd-DTPA prepared by this ionophoretic loading procedure exhibits biodistribution and clearance characteristics similar to 153Gd-DTPA-labeled liposomes prepared by means of passive entrapment of the preformed chelate.
我们已经开发出一种改进的生产脂质体钆-二乙三胺五乙酸（Gd-DTPA）的方法。离子载体A23187有助于将外部添加的钆摄取到单层脂质囊泡的内部水相中，在那里它被被动包封的二乙三胺五乙酸螯合，从而原位形成Gd-DTPA螯合物。囊泡膜上pH梯度的存在对于钆的摄取不是必需的，其摄取程度显然仅受螯合剂内部浓度的限制。一旦在内部形成，Gd-DTPA复合物在室温下可在囊泡内保留至少几天。在小鼠体内的生物分布研究表明，通过这种离子载体加载程序制备的脂质体Gd-DTPA表现出与通过预先形成的螯合物被动包封制备的153Gd-DTPA标记脂质体相似的生物分布和清除特征。
