title: Preparation of liposomes entrapping a high specific activity of 111In3+-bound inulin.
abstract: 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.
authors.affiliation: School of Pharmacy, University of Southern California, Los Angeles 90033.
authors.forename: H
authors.initials: H
authors.lastname: Essien
authors.forename: K J
authors.initials: KJ
authors.lastname: Hwang
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine; D055598:Chemical Phenomena; D002621:Chemistry; D002784:Cholesterol; D004705:Endocytosis; D007204:Indium; D007444:Inulin; D008081:Liposomes; D013109:Sphingomyelins; D014334:Tropolone
chemical_list: D008081:Liposomes; D013109:Sphingomyelins; D007204:Indium; D015060:1,2-Dipalmitoylphosphatidylcholine; D014334:Tropolone; D007444:Inulin; D002784:Cholesterol