CHS-828 (N-(6-(4-chlorophenoxy)hexyl)-N′-cyano-N″-4-pyridyl guanidine) is an anticancer agent with low bioavailability and high systemic toxicity. Here we present an approach to improve the therapeutic profile of the drug using photolabile ruthenium complexes to generate light-activated prodrugs of CHS-828. Both prodrug complexes are stable in the dark but release CHS-828 when irradiated with visible light. The complexes are water-soluble and accumulate in tumour cells in very high concentrations, predominantly in the mitochondria. Both prodrug complexes are significantly less cyototoxic than free CHS-828 in the dark but their toxicity increases up to 10-fold in combination with visible light. The cellular responses to light treatment are consistent with release of the cytotoxic CHS-828 ligand.

CHS-828（N-（6-（4-氯苯氧基）己基）-N'-氰基-N ''-4-吡啶基胍）是一种生物利用度低，全身毒性高的抗癌药。在这里，我们提出一种使用光不稳定的钌配合物来产生CHS-828的光活化前药来改善药物治疗效果的方法。两种前药复合物在黑暗中都是稳定的，但是在可见光照射下会释放CHS-828。该复合物是水溶性的，并且以非常高的浓度积累在肿瘤细胞中，主要集中在线粒体中。在黑暗中，两种前药复合物的细胞毒性均明显低于游离CHS-828，但与可见光结合，其毒性最高可增加10倍。细胞对光处理的反应与细胞毒性CHS-828配体的释放一致。