'3+1' mixed-ligand oxotechnetium(V) complexes with affinity for melanoma: synthesis and evaluation in vitro and in vivo.
'3+1' Mixed-ligand [(99m)Tc]oxotechnetium complexes with affinity for melanoma were synthesized in a one-pot reaction. Complexation of technetium-99m with a mixture of N-R(3-azapentane-1,5-dithiol) [R = Me, Pr, Bn, Et(2)N(CH(2))(2)] and N-(2-dialkylamino)ethanethiol [alkyl = X = Et, Bu, morpholinyl] using Sn(2+) as the reducing agent resulted in the formation of '3+1' mixed-ligand technetium-99m complexes [TcO(SN(R)S)(SNX(2))] in high radiochemical yield (60-98%). In vitro uptake studies in B16 murine melanoma cells indicated a moderate tumor-cell accumulation (40%) of compound 1 [R = Me, X = Et] and a higher accumulation (69%) of compound 2 [R = Me, X = Bu] after a 60-min incubation. In vivo evaluation of compounds 1-6 in the C57Bl6/B16 mouse melanoma model demonstrated tumor localization. Compound 2 displayed the highest accumulation with up to 5% ID/g at 60 min after injection. In vivo, 2 also showed a low blood-pool activity and high melanoma/spleen (4.3) and melanoma/lung (1.9) ratios at 1 h. These results suggest that small technetium-99m complexes could be useful as potential melanoma-imaging agents.
Friebe
M
M
Department of Radiology, Harvard Medical School and Brigham and Women's Hospital, Boston, Massachusetts 02115, USA.
Mahmood
A
A
Spies
H
H
Berger
R
R
Johannsen
B
B
Mohammed
A
A
Eisenhut
M
M
Bolzati
C
C
Davison
A
A
Jones
A G
AG
D000818:Animals; D008545:Melanoma / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008815:Mice, Inbred Strains; D009025:Morpholines / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D009368:Neoplasm Transplantation; D015609:Organotechnetium Compounds / Q000138:chemical synthesis* / Q000737:chemistry / Q000493:pharmacokinetics; D019275:Radiopharmaceuticals / Q000138:chemical synthesis* / Q000737:chemistry / Q000493:pharmacokinetics; D013329:Structure-Activity Relationship; D013438:Sulfhydryl Compounds / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D009025:Morpholines; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D013438:Sulfhydryl Compounds