基于具有四个铁 (III) 中心的自组装配位笼的 T1 MRI 探针充当金 (I) 抗癌药物 Au(PEt3)Cl 水解产物的宿主。封装在配位笼的抗磁性 Ga(III) 类似物内的金配合物的 1H NMR 表征与氯离子损失一致，得到水合金配合物，很可能是笼内的 [Au(PEt3)(OH2)]。金络合物在 Ga(III) 笼中经历 pH 依赖性形态变化，并在弱酸性 pH 条件下从 Ga(III) 和 Fe(III) 笼中释放。在人血清白蛋白 (HSA) 存在下对封装的金复合物进行 NMR 光谱研究表明，金复合物在 Ga(III) 笼内保留数小时，阻止释放并与 HSA 的半胱氨酸残基结合。 MRI 显示，封装有金复合物的 Fe(III) 笼显示 BALB/c 小鼠的脉管系统对比度增强，并且对 CT26 肿瘤的摄取也增强。金络合物被铁(III)笼溶解以进行静脉注射，而游离络合物必须腹膜内注射。通过离体分析测量，金复合物在 1-48 小时内在肿瘤中积累，无论是笼状复合物还是游离复合物。与游离复合物相比，封装在 Fe(III) 笼中可调节小鼠体内金络合物的生物分布，这与笼作为载体的功能一致。

A T1 MRI probe based on a self-assembled coordination cage with four iron(III) centers acts as a host for the hydrolysis product of the gold(I) anticancer drug, Au(PEt3)Cl. 1H NMR characterization of the gold complex encapsulated within the diamagnetic Ga(III) analog of the coordination cage is consistent with loss of chloride to give aquated gold complex, most likely [Au(PEt3)(OH2)]+ within the cage. The gold complex undergoes pH-dependent speciation changes in the Ga(III) cage and is released at mildly acidic pH from both the Ga(III) and Fe(III) cages. NMR spectroscopy studies of the encapsulated gold complex in the presence of human serum albumin (HSA) show that the gold complex remains inside of the Ga(III) cage for several hours, resisting release and binding to cysteine residues of HSA. The Fe(III) cage with encapsulated gold complex shows enhanced contrast of the vasculature and uptake into CT26 tumors in BALB/c mice as shown by MRI. The gold complex is solubilized by the iron(III) cage for intravenous injection, whereas the free complex must be injected intraperitoneally. Gold complex accumulates in the tumor for both caged and free complex over 1-48 h as measured by ex-vivo analysis. Encapsulation in the Fe(III) cage modulates the biodistribution of the gold complex in mice in comparison to the free complex, consistent with the function of the cage as a carrier.