Essien H, Hwang K J
School of Pharmacy, University of Southern California, Los Angeles 90033.
Biochim Biophys Acta. 1988 Oct 20;944(3):329-36. doi: 10.1016/0005-2736(88)90502-0.
Targeting liposomes to specific tissues or cells require the unequivocal determination of the uptake of liposomes at the cellular level. The present report describes the preparation of liposomes entrapping a high specific activity of 111In3+-bound inulin, and the potential applications of a multiple labeling technique for characterizing the extent of uptake of liposomes by tissues or different cells in a given tissue in vivo. The labeling method involves the application of the technique of acetylacetone-mediated, ionophoric loading of 111In3+ into liposomes entrapping an inulin derivative to which a strong chelating agent, diethylenetriamine-pentaacetic acid (DTPA), is bound. Subsequent ionophoric removal of the weakly bound 111In3+ by incubating the previously 111In3+-loaded liposomes with 10 mM nitrilotriacetic acid and 100 microM tropolone at room temperature for 20 min results in the preparation of liposomes entrapping 111In3+-DTPA-inulin. Our method of preparation yields net efficiencies of converting 63-78% of the externally added 111In3+ to liposome-entrapped 111In3+-DTPA-inulin.
将脂质体靶向特定组织或细胞需要在细胞水平上明确测定脂质体的摄取情况。本报告描述了包裹高比活度的¹¹¹In³⁺结合菊粉的脂质体的制备方法，以及一种多重标记技术在体内表征组织或给定组织中不同细胞对脂质体摄取程度的潜在应用。标记方法包括应用乙酰丙酮介导的离子载体将¹¹¹In³⁺负载到包裹有菊粉衍生物的脂质体中，该菊粉衍生物与强螯合剂二乙烯三胺五乙酸（DTPA）结合。随后，通过在室温下将先前负载有¹¹¹In³⁺的脂质体与10 mM次氮基三乙酸和100 μM托酚酮孵育20分钟，离子载体去除弱结合的¹¹¹In³⁺，从而制备出包裹¹¹¹In³⁺-DTPA-菊粉的脂质体。我们的制备方法将外部添加的¹¹¹In³⁺转化为脂质体包裹的¹¹¹In³⁺-DTPA-菊粉的净效率为63-78%。
