Lightening up Ruthenium Complexes to Fight Cancer?

Abstract

In medicine, light is used in a medical treatment called photodynamic therapy (PDT) to treat some types of cancer and skin diseases. This technique generally allows for reduced side effects compared to traditional chemotherapy. However, PDT is not fully effective on hypoxic tumors (i.e. lacking oxygen). To overcome this important drawback, photoactivated chemotherapy (PACT) agents have been designed to obtain light-mediated cancer cell death via an oxygen-independent mechanism. Ruthenium complexes have already been and are currently deeply explored as traditional anticancer agents. However, as reported in this short review article, such compounds can also bring novel opportunities in the field of light-mediated cancer treatment. Herein, we report on our findings in the optimization of Ru(ii) polypyridyl complexes as PDT and PACT agents for the potential treatment of cancer and, interestingly, also of bacterial infections.

Enhanced cellular uptake and photochemotherapeutic potential of a lipophilic strained Ru(ii) polypyridyl complex

“…40 This is commonly assessed by measuring the difference in cytotoxicity in vitro between dark and light conditions, known as the photoindex or PI (PI ¼ IC 50 dark/IC 50 light). 41 Cellular uptake plateaued aer 12 h for complexes 1 and 2 (Fig. 7), thus cell survival assays were performed aer a 12 h incubation period with the complexes.…”

Functional Dimming of Pincer‐Shaped Bibenzimidazole‐Ruthenium(II) Complexes with Improved Anion‐Sensitive Luminescence

“…[5,6] A potent approach to detect anions through hydrogen bonds is to connect one or more acidic H-donor functions with a luminophore in a way that the absorption and emission properties of the latter are visibly influenced by the appearance and strength of the Hbond interaction. [7,8] On the one hand, polypyridyl-ruthenium(II) complexes are widely applicable molecular tools for the introduction of light in technological and biological applications [9][10][11][12] because of their well-known photophysical properties and generally long-lived excited states, in which light energy is absorbed and provided for chemical conversions. [13,14] On the other hand, the vast synthetic variability of the general tris(diimine) framework allows the adjustment of a chromophore for a distinct application.…”

Evaluation of Perylene Bisimide‐Based RuII and IrIII Complexes as Photosensitizers for Photodynamic Therapy

“…[13][14][15] In the last years, our groups focused attention in the development of new Ru II -based PSs for PDT, antibacterial PDT (aPDT) and photoactivated chemotherapy (PACT). [16][17][18][19][20][21][22][23][24][25][26] Besides ruthenium, [27][28][29][30][31][32] other metals, such as iridium(III), rhenium(I), [33][34][35][36][37][38] Fe III , [39] Co III , [40] and Gd III [41] have been investigated by us and other groups in regard to traditional chemotherapy and PDT applications. [42][43][44][45] Compared with the Ru complexes, less effective PDT agents based on Ir compounds have been reported so far, probably because of the difficulties in suppressing the competing electron-transfer processes.…”