normoxia. The photosensitizer exhibited an unprecedented PI > 90 (EC50 = 0.651 μM) in hypoxia (1% O2) with visible and green light, and a PI > 70 with red light. Os-4T was also active with 733 nm near-infrared light (EC50 = 0.803 μM, PI = 77) under normoxia. Both computation and spectroscopic studies confirmed a switch in the nature of the lowest-lying triplet excited state from triplet metal-to-ligand
低氧对癌症的治疗提出了两方面的挑战,因为低氧条件会诱发
生物学变化,使恶性组织同时更具侵略性,并且对标准
化学疗法的敏感性降低。本文报道了第一种接近光疗剂理想性能的
金属基光敏剂。基于Os(phen)2的支架与一系列IP- n T
配体结合,其中phen = 1,10-
菲咯啉,IP- n T =
咪唑并[4,5- f ] [1,10]
菲咯啉至n = 0–4
噻吩环。Os-4T(n= 4)成为该系列中最有前途的复合物,在常氧状态下具有皮摩尔活性和光疗指数(
PI)超过10 6。该光敏剂在可见光和绿光下的缺氧(1%O 2)表现出前所未有的
PI> 90(
EC 50 = 0.651μM),
PI在70以上的红光。在常氧下,Os-4T在733 nm近红外光下(
EC 50 = 0.803μM,
PI = 77)也具有活性。两个计算和光谱研究证实在最低地势三重激发态的性质的开关从三重态的
金属-
配体电荷转移(3 MLCT)