Two novel BODIPY–Ru(ii) arene dyads enabling effective photo-inactivation against cancer cells

Abstract

BODIPY (boron dipyrromethene) derivatives and Ru(ii) complexes are two types of functional compounds that have found wide applications in the fields of biology and medicine. We herein synthesized two new Ru(ii) arene complexes based on an iodized BODIPY-containing pyridine (py-I-BODIPY) ligand, [(p-cym)Ru(bpy)(py-I-BODIPY)](2+) (2) and [(p-cym)Ru(2-pydaT)(py-I-BODIPY)](2+) (3), where p-cym = para-cymene, bpy = 2,2'-bipyridine, and 2-pydaT = 2,4-diamino-6-(2-pyridyl)-1,3,5-triazine. The photophysical, photochemical and photobiological properties of 2 and 3 were compared with that of [(p-cym)Ru(bpy)(py-BODIPY)](2+) (1). While 1 undergoes efficient monodentate ligand dissociation upon visible light irradiation and therefore may photobind DNA as a potential photoactivated chemotherapy (PACT) agent, 2 and 3 can generate (1)O2 effectively and thus may serve as photosensitizers in photodynamic therapy (PDT). In electrophoresis experiments, 2 and 3 are even able to retard the mobility of plasmid DNA in the dark at high concentrations. More importantly, the cytotoxicities of 2 and 3 against human ovarian adenocarcinoma SKOV3 cells are enhanced about ten times under irradiation, leading to cytotoxicities more than one order of magnitude higher than that of cisplatin, demonstrating an efficient hybridization of the iodized BODIPY chromophore and the Ru(ii) arene complex.

Mitochondria‐Targeted Anticancer Activity of BODIPY‐Appended Iron(III) Catecholates in Red Light

“…To enhance the PDT activity of the ternary iron(III) catecholates, we have designed new ternary complexes of formulation [Fe III (L)(cat)Cl], where L is BODIPY‐based photosensitizers that are capable of generating singlet oxygen on visible light irradiation for PDT or can be used for cellular imaging based on their spectral properties. The BODIPY (boron‐dipyrromethene) derivatives have been extensively used as photosensitizers generating singlet oxygen on light activation . Many BODIPY compounds have been studied as in vitro fluorescent probes to study their subcellular localization.…”

Understanding the Synergistic Effects Observed When Using Tethered Dual Catalysts for Heat and Light Activated Catalysis

“…As such, a variety of tethered photocatalyst-metal complexes have been developed and used in applications that require singlet oxygen generation, such as photocatalysis [24][25][26][27][28] and photodynamic therapy. [26,[29][30] Despite the increasing use of tethered catalysts that feature both a photocatalyst and a transition metal catalyst, [23,25,28,[31][32][33][34] there have been limited mechanistic investigations into the origins of the synergistic effects between the catalytic centres. For example, our group recently developed a series of complexes that feature an organic photocatalyst (1,3,5,7tetramethyl-8-phenyl-4,4-difluoroboradiazaindacene, BDP 1) tethered to an Ir complex ligated with a bis(pyrazolemethane) (bpm) ligand, Ir(I) 2 ( Figure 2).…”

Photoinduced Electron Transfer‐based Halogen‐free Photosensitizers: Covalent meso‐Aryl (Phenyl, Naphthyl, Anthryl, and Pyrenyl) as Electron Donors to Effectively Induce the Formation of the Excited Triplet State and Singlet Oxygen for BODIPY Compounds

“…We show now that BODIPYs( Scheme1)a re able to generate the T 1 state based on ad ifferent mechanism.B ODIPY and its derivatives are well-known highlyf luorescent materials for various applications, [13][14][15][16][17] but these dyes lack the ability to produce the T 1 state upon photo excitation. [12,18,19] Unsubstituted BODIPY,f or example, shows fluorescencee fficiency near unity (0.97 AE 0.03) and al ong fluorescence lifetime of 6.89 ns in methanol, [20] which leaves it little space to form the T 1 state.…”