Radiolabeling of MAG3-morpholino oligomers with 188Re at high labeling efficiency and specific radioactivity for tumor pretargeting

Appl Radiat Isot. 2006 Sep;64(9):971-8. doi: 10.1016/j.apradiso.2006.04.005. Epub 2006 May 30.

Abstract

We are investigating a novel pretargeting approach involving an initial IV injection of antitumor antibody conjugated with a phosphorodiamidate morpholino oligomer (MORF, a DNA analog) and the subsequent IV injection of the radiolabeled complement oligomer (cMORF). In this paper, the cMORF was labeled with (188)Re using MAG(3) as chelator for therapeutic applications. Since (c)MORFs are unstable in acidic condition, an optimal labeling pH was first selected and the other labeling factors were then examined. A labeling efficiency of greater than 90% can be achieved even at a concentration of MAG(3)-cMORF as low as 0.8 microM. The labeled cMORF is stable and capable of hybridizing to its complement.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Chromatography, High Pressure Liquid
  • Isotope Labeling / methods*
  • Mice
  • Morpholines / chemistry*
  • Morpholinos
  • Oligopeptides / isolation & purification*
  • Organometallic Compounds / isolation & purification*
  • Radioisotopes / isolation & purification*
  • Radiopharmaceuticals / chemistry*
  • Radiopharmaceuticals / pharmacokinetics
  • Rhenium / isolation & purification*

Substances

  • Morpholines
  • Morpholinos
  • Oligopeptides
  • Organometallic Compounds
  • Radioisotopes
  • Radiopharmaceuticals
  • rhenium-mercaptoacetyltriglycine
  • Rhenium