A newly synthesized 18-membered hexaamine carrying an acetate moiety on each nitrogen, L2, has been demonstrated to be a more efficient dissolving agent that ethylenediaminetetraacetic acid for human urinary calculi whose major components are calcium phosphate and magnesium phosphate. L2 is a good chelating agent for Ca2+ and Mg2+, and this chelating action is presumably responsible for the dissolution of inorganic calculi.
Improved in Vivo Stability of Actinium-225 Macrocyclic Complexes
作者:Kim A. Deal、Ila A. Davis、Saed Mirzadeh、Stephen J. Kennel、Martin W. Brechbiel
DOI:10.1021/jm990141f
日期:1999.7.1
The favorable nuclear properties of actinium-225 (Ac-225) have led to proposal of this isotope for use in radioimmunotherapy. In an effort to reduce the toxicity of free Ac-225, a series of ligands were evaluated for stability in vivo. Loss of Ac-225 from acyclic chelating agents resulted in high liver uptake and poor whole body clearance. The macrocyclic ligands c-DOTA, PEPA, and HEHA were evaluated, and Ac-225-HEHA showed exceptional stability in vivo. Ac-225 chelated with EDTA, DTPA, DOTA, or PEPA permitted substantial accumulation of the radionuclide to the Liver, while the Ac-225-HEHA complex was essentially excreted within minutes of administration. The preparation of the ligands and radiolabeled complexes and the biodistribution results will be discussed.