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Retracted: Synthesis, Characterization, and Preclinical Evaluation of 99m Tc‐Labeled Macrobicyclic and Tricyclic Chelators as Single Photon Emission Computed Tomography Tracer
Author(s) -
Yadav Neelam,
Chuttani Krishna,
Mishra Anil K.,
Singh Bachcha
Publication year - 2016
Publication title -
chemical biology and drug design
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.59
H-Index - 77
eISSN - 1747-0285
pISSN - 1747-0277
DOI - 10.1111/cbdd.12707
Subject(s) - tricyclic , emission computed tomography , single photon emission computed tomography , tracer , chemistry , characterization (materials science) , technetium , radiochemistry , positron emission tomography , nuclear medicine , stereochemistry , physics , materials science , nanotechnology , nuclear chemistry , nuclear physics , medicine
The novel tetraaza macrobicyclic chelator 3,6,9,15‐tetraazabicyclo[9.3.1]pentadeca‐1(15),11,13‐triene‐2,10‐dione ( TBPD ) and pentaaza macrotricyclic chelator 9‐oxa‐3,6,12,15,21‐pentaazatricyclo[15,3,2,1]trieicos‐1(21),17,19‐triene‐2,7,11,16‐tetradione ( OPTT ) were synthesized, characterized, and radiolabeled with 99m Tc to produce 99m Tc‐ TBPD and 99m Tc‐ OPTT . These radiolabeled complexes were prepared with high radiolabeling yield, radiochemical purity, and good in vitro stability up to 24 h. The labeling efficiency of 99m Tc‐ TBPD and 99m Tc‐ OPTT was found 98% and 97%. In vitro serum stability of 99m Tc‐ TBPD was found to be 95.2%, while that of 99m Tc‐ OPTT 94.2% up to 24 h. Blood kinetics experiments of 99m Tc‐labeled complexes showed biphasic pattern of blood clearance. About 99.57 ± 0.89% activity of 99m Tc‐ TBPD and 99.42 ± 0.88% activity of 9m Tc‐ OPTT were cleared off blood stream at 24 h postadministration. The biological half‐life of 99m Tc‐ TBPD was observed: t 1/2 (F) 1 h 5 min and t 1/2 (S) 12 h and biological half‐life of 99m Tc‐ OPTT was observed: t 1/2 (F) 1 h 10 min and t 1/2 (S) 9 h 50 min, respectively. The biodistribution studies revealed that maximum uptake of 99m Tc‐ TBPD was found in liver, concluded that excretory pathway is hepatobiliary, while that of 99m Tc‐ OPTT was renal as well as hepatobiliary. The negligible activity observed in stomach confirming the stability of radiolabeled complex in biological milieu. In vitro cytotoxicity study of TBPD and OPTT did not show any considerable antiproliferative activity against cancer cells of human cervical SW 756, HeLa, and glioblastoma U‐87, U373 cell lines.