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

Abstract

In the present study, a cyclometalated iridium(III) complex, [Ir(ppy)2(HPIP)]Cl (IrT, ppy = 2-phenylpyridine, HPIP = 2-(2-hydroxyphenyl)imidazo[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.