Photodynamic therapy (PDT) is a noninvasive medical technique that has received increasing attention over the last years and been applied for the treatment of certain types of cancer. However, the currently clinically used PDT agents have several limitations, such as low water solubility, poor photostability, and limited selectivity towards cancer cells, aside from having very low two-photon cross-sections around 800 nm, which limits their potential use in TP-PDT. To tackle these drawbacks, three highly positively charged ruthenium(II) polypyridyl complexes were synthesized. These complexes selectively localize in the lysosomes, an ideal localization for PDT purposes. One of these complexes showed an impressive phototoxicity index upon irradiation at 800 nm in 3D HeLa multicellular tumor spheroids and thus holds great promise for applications in two-photon photodynamic therapy.

Recently, coordinatively saturated and substitutionally inert Ru(II) complexes have been investigated as anticancer agents. Herein a cyclometalated Ru(II) complex, [Ru(bpy)(phpy)(dppz)](+), was found to be rapidly taken up by cancer cells, and nearly 90% of the complex accumulated in the nuclei of cancer cells after a 2 h incubation. The anticancer activity of this complex was screened against a panel of cancer cell lines. Remarkably, it exhibited IC50 values that were an order of magnitude lower than those of cisplatin. This complex also displayed potencies superior to those of cisplatin against 3D tumor spheroids. Further studies revealed that the high DNA binding affinity of [Ru(bpy)(phpy)(dppz)](+) resulted in effective disruption of the binding of transcription factor NF-κB to DNA sequences, thereby inhibiting cellular transcription and leading to irreversible cancer cell apoptosis. Our work provides new insights into understanding the biological interactions and anticancer molecular mechanisms of DNA-specific Ru(II) polypyridyl complexes.

Photodynamic therapy( PDT) is an oninvasive medical technique that has received increasing attention over the last years and been applied for the treatment of certain types of cancer.H owever,t he currently clinically used PDT agents have several limitations,s uch as low water solubility,p oor photostability,and limited selectivity towards cancer cells,aside from having very lowt wo-photon cross-sections around 800 nm, whichl imits their potential use in TP-PDT.T o tackle these drawbacks,t hree highly positively charged ruthenium(II) polypyridyl complexes were synthesized. These complexes selectively localizei nt he lysosomes,a ni deal localization for PDT purposes.O ne of these complexes showed an impressive phototoxicity index upon irradiation at 800 nm in 3D HeLa multicellular tumor spheroids and thus holds great promise for applications in two-photon photodynamic therapy.

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An AIPE-active iridium(III) complex was found to possess high specificity for mitochondria, superior photostability, low cytotoxicity, and high resistance to the loss of mitochondrial membrane potential. Thus, this complex can be used for mitochondrial imaging and tracking in living cells.