title: Radiolabeling of MAG3-morpholino oligomers with 188Re at high labeling efficiency and specific radioactivity for tumor pretargeting.
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.
authors.affiliation: Division of Nuclear Medicine, Department of Radiology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA. guozheng.liu@umassmed.edu
authors.forename: Guozheng
authors.initials: G
authors.lastname: Liu
authors.forename: Shuping
authors.initials: S
authors.lastname: Dou
authors.forename: Jiang
authors.initials: J
authors.lastname: He
authors.forename: Dongguang
authors.initials: D
authors.lastname: Yin
authors.forename: Suresh
authors.initials: S
authors.lastname: Gupta
authors.forename: Surong
authors.initials: S
authors.lastname: Zhang
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
authors.forename: Mary
authors.initials: M
authors.lastname: Rusckowski
authors.forename: Donald J
authors.initials: DJ
authors.lastname: Hnatowich
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid; D007553:Isotope Labeling / Q000379:methods*; D051379:Mice; D009025:Morpholines / Q000737:chemistry*; D060172:Morpholinos; D009842:Oligopeptides / Q000302:isolation & purification*; D009942:Organometallic Compounds / Q000302:isolation & purification*; D011868:Radioisotopes / Q000302:isolation & purification*; D019275:Radiopharmaceuticals / Q000737:chemistry* / Q000493:pharmacokinetics; D012211:Rhenium / Q000302:isolation & purification*
chemical_list: D009025:Morpholines; D060172:Morpholinos; D009842:Oligopeptides; D009942:Organometallic Compounds; D011868:Radioisotopes; D019275:Radiopharmaceuticals; C114893:rhenium-mercaptoacetyltriglycine; D012211:Rhenium