A phosphorescent cyclometalated iridium(III) complex as mitochondria-targeted theranostic anticancer agent

In the present study, a cyclometalated iridium(III) complex, (Ir(ppy)(2)(HPIP))Cl (IrT, ppy = 2-phenylpyridine, HPIP = 2-(2-hydroxyphenypimidazo[4,5-f]1,10-phenanthroline), was synthesized and characterized. IrT exhibited more cytotoxicity than cisplatin did against several screened cancer cell lines. In particular, the cytotoxicity of IrT against the cisplatin-resistant cell line A549-CP/R is approximately 10 times higher than that of cisplatin. In addition, this complex could perform theranostic functions by simultaneously imaging and tracking mitochondrial morphological changes. Further-study suggested that IrT induced changes in the mitochondrial membrane potential and triggered apoptosis via an intrinsic mitochondria-mediated pathway. Thus, IrT exhibited both antitumor and imaging properties, indicating that IrT may be a viable drug candidate as a mitochondria-targeted theranostic anticancer agent.