‘3+1' Mixed-Ligand Oxotechnetium(V) Complexes with Affinity for Melanoma: Synthesis and Evaluation in Vitro and in Vivo
作者:Matthias Friebe、Ashfaq Mahmood、Hartmut Spies、Ralf Berger、Bernd Johannsen、Ashour Mohammed、Michael Eisenhut、Cristina Bolzati、Alan Davison、Alun G. Jones
DOI:10.1021/jm000050e
日期:2000.7.1
'3+1' Mixed-ligand [Tc-99m]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, Et2N(CH2)(2)] and N-(2-dialkylamino)ethanethiol [alkyl = X = Et, Bu, morpholinyl] using Sn2+ as the reducing agent resulted in the formation of '3+1' mixed-ligand technetium-99m complexes [TcO(SN(R)S)(SNX2)] 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 C57B16/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.
**'3+1'型杂配位体[Tc-99m]氧肟technetium复合物的合成及其对黑色素瘤的靶向性研究**
在一步锅法反应中,成功合成了一种对黑色素瘤具有亲和力的'3+1'型杂配位体 [Tc-99m]oxotechnetium 复合物。通过将 technetium-99m 与 N-R(3-氮杂戊烷-1,5-二硫醇)[R = Me, Pr, Bn, Et2N(CH2)2] 和 N-(2-双烷基氨基)乙烷硫醇 [烷基 = X = Et, Bu, 吗啉基] 的混合物中的 technetium-99m 复合,并使用 Sn²+ 作为还原剂,最终形成了'3+1'型杂配位体 technetium-99m 复合物 [TcO(SN(R)S)(SNX2)],其放射化学产率高达 60-98% 。
体外实验中,利用 B16 小鼠黑色素瘤细胞进行的摄取研究表明,化合物 1 [R = Me, X = Et] 在60 分钟孵育后的肿瘤细胞积聚量为 40%,而化合物 2 [R = Me, X = Bu] 则达到了 69% 的较高积聚量。在 C57B16/B16 小鼠黑色素瘤模型中,对化合物 1-6 进行的体内评估显示,这些化合物均表现出肿瘤定位能力。其中,化合物 2 在注射后60 分钟内达到最高的积聚量,为 5% ID/g 。
进一步的体内研究表明,化合物 2 在1 小时时表现出较低的血液活性,并且其黑色素瘤/脾脏(4.3)和黑色素瘤/肺(1.9)比值显著升高。这些结果表明,小巧的 technetium-99m 复合物有望成为潜在的黑色素瘤成像剂。