Developing photo-activable ruthenium (II) complexes for PDT: Synthesis, characterization, photophysical and biological studies
dc.contributor.author
dc.date.accessioned
2024-02-15T07:36:16Z
dc.date.available
2024-02-15T07:36:16Z
dc.date.issued
2024-05-01
dc.identifier.issn
0143-7208
dc.identifier.uri
dc.description.abstract
The easy tunable photophysical properties of Ru(II) polypyridyl complexes, together with their water solubility, photochemical stability and high biocompatibility make them suitable as agents for photodynamic therapy (PDT). The development of complexes containing new ligands is a step forward in the improvement and application of these compounds as photosensitizer and photocytotoxic agents. We report the synthesis of a set of Ru(II)-polypyridyl complexes with different electronic properties and delocalized π systems: one homoleptic complex [RuII(dpbpy)3](PF6)2 (1), and three heteroleptic complexes [RuII(dpbpy)2(phen)](PF6)2 (2), [RuII(dpbpy)(phen)2](PF6)2 (3) and [RuII(dpbpy)2(CN–Me)](PF6)2 (4). All of them contain 4,4′-diphenyl-2,2′-bipyridine (dpbpy) and 1,10-phenantroline (phen) or N-methyl-N′-2-pyridilimidazolium (CN–Me) ligands. The complexes have been characterized by spectroscopic, structural and electrochemical methods. UV–vis absorption in solution show the red shift for the metal to ligand charge transfer (MLCT) transitions after changing phen by dpbpy and carbene ligands. The photoluminescence emission spectra of 1–4 supported by theoretical calculations using time-dependent density-functional theory (TDDFT) suggest that the lowest energy excited state is mainly 3MLCT. Complex 2 exhibits the highest phosphorescence emission with a quantum yield (ΦP) in CH2Cl2 of 44.1 %, followed by complex 1 (ΦP = 40.0 %), whereas complex 4 shows the lowest quantum efficiency (ΦP = 16.0 %), what suggest that the introduction of the CN–Me carbene ligand produces a significant quenching of the phosphorescence. Phosphorescence triplet state lifetimes between 0.96 and 1.74 μs were shown for 1–4 in degassed CH2Cl2. All complexes are proven to be efficient singlet oxygen photosensitizers. The trend in the redox potentials becomes more positive by increasing the number of phen ligands in the complexes, in full agreement with the HOMO's energy level and the blue shift of the MLCT transitions in the absorption spectra. Complexes internalization was analysed in tumorigenic mammary epithelial SKBR-3 cells, being complexes 1 and 2 the most well internalized. The effect of the photodynamic treatment using light-activated complexes 1 and 2 for 10 min demonstrated to increase cell death, being the homoleptic complex 1 an outstanding candidate as potential theranostic agent for bioimaging and PDT
dc.description.sponsorship
This work was financially supported by AGAUR (Generalitat de Catalunya, projects 2021-SGR-00442, 2021-SGR-00064 and 2021-SGR-00122), UdG (Universitat de Girona, PONT2020/05), MICINN (Ministerio de Ciencia e Innovación, projects PID2019-106832RB-I00, PID2019-105622RB-I00, PID2020-116844RB-C21, PID2022-136892NB-I00) and the Severo Ochoa Program for Centers of Excellence for the FUNFUTURE CEX2019-000917-S project). S. S. acknowledges financial support from DOC-FAM, European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 754397. Z. K. is grateful for the general support of János Bolyai Research Scholarship, Project UNKP-22-5-BME-298 and TKP2021-EGA-02 provided by the Ministry of Innovation and Technology of Hungary
dc.format.mimetype
application/pdf
dc.language.iso
eng
dc.publisher
Elsevier
dc.relation.isformatof
Versió postprint del document publicat a: https://doi.org/10.1016/j.dyepig.2024.111985
dc.relation.ispartof
© Dyes and Pigments, 2024, vol. 224, art.núm. 111985
dc.relation.ispartofseries
Articles publicats (D-Q)
dc.rights
Attribution-NonCommercial-NoDerivatives 4.0 International
dc.rights.uri
dc.subject
dc.title
Developing photo-activable ruthenium (II) complexes for PDT: Synthesis, characterization, photophysical and biological studies
dc.type
info:eu-repo/semantics/article
dc.rights.accessRights
info:eu-repo/semantics/embargoedAccess
dc.date.embargoEndDate
info:eu-repo/date/embargoEnd/2026-05-01
dc.type.version
info:eu-repo/semantics/acceptedVersion
dc.identifier.doi
dc.identifier.idgrec
038164
dc.type.peerreviewed
peer-reviewed
dc.identifier.eissn
1873-3743