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The photoreactive [Ru(TAP)2(phen)]2+ (TAP = 1,4,5,8-tetraazaphenanthrene; phen = 1,10-phenanthroline) complex tethered to the cell-penetrating peptide (CPP) TAT was studied in vitro and in cellulo. The tethering of the complex does not affect its behavior under blue-light irradiation in the presence of guanine-containing oligodeoxyribonucleotides (ODNG). Thus, the luminescence is quenched in the presence of ODNG, and gel electrophoresis experiments showed the appearance of products corresponding to the irreversible attachment of the conjugate to ODNG upon illumination. The cellular uptake of the conjugate was examined by flow cytometry, inductively coupled plasma mass spectrometry (ICP-MS), and confocal imaging microscopy. These experiments showed that the [Ru(TAP)2(phen-TAT)] conjugate is readily taken up by HeLa cells and, despite these favorable factors, the cellular survival was 100 %, as measured by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. A possible origin of the inactivity of [Ru(TAP)2(phen-TAT)] under irradiation is proposed on the basis of the fluorescence-activated cell sorting (FACS), ICP-MS, and confocal microscopy results.

The photoreactive [Ru(TAP)2(phen)]2+(TAP = 1,4,5,8-tetraazaphenanthrene; phen = 1,10-phenanthroline) complex tethered to the cell-penetrating peptide (CPP) TAT was studied in vitro and in cellulo. The tethering of the complex does not affect its behavior under blue-light irradiation in the presence of guanine-containing oligodeoxyribonucleotides (ODNG). Thus, the luminescence is quenched in the presence of ODNG, and gel electrophoresis experiments showed the appearance of products corresponding to the irreversible attachment of the conjugate to ODNGupon illumination. The cellular uptake of the conjugate was examined by flow cytometry, inductively coupled plasma mass spectrometry (ICP-MS), and confocal imaging microscopy. These experiments showed that the [Ru(TAP)2(phen-TAT)] conjugate is readily taken up by HeLa cells and, despite these favorable factors, the cellular survival was 100 %, as measured by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. A possible origin of the inactivity of [Ru(TAP)2(phen-TAT)] under irradiation is proposed on the basis of the fluorescence-activated cell sorting (FACS), ICP-MS, and confocal microscopy results., SCOPUS: ar.j, FLWIN, info:eu-repo/semantics/published

RuII-TAP complexes have been shown to be very attractive compounds in the frame of developments of new anticancer drugs targeting the genetic material. This increasing interest originates from observations of covalent bond formations, triggered by photo-induced electron transfer (PET) between RuII-TAP complexes and guanine bases of DNA. This photoreaction has recently been extended to the tryptophan (Trp) amino acid for future applications involving peptides. Thus, a double photo-addition of Trp residues of peptides on RuII complexes is demonstrated by mass spectrometry with some structural issues. Such bi-adduct formations offer the possibility of photocrosslinking two Trp-containing biomolecules, which is investigated in this study. Thus, photocrosslinking between two complementary oligonucleotides (ODNs) derivatized by Trp-containing tripeptides is demonstrated by polyacrylamide gel electrophoresis (PAGE) in the presence of RuII-TAP complexes. Both PAGE and MS indicate that such photocrosslinkings arise from two reaction pathways: either via the double addition of Trp residues on the Ru complex or from dimerization of Trp radicals. The competition between these two pathways depends on the experimental conditions. Heterobridgings between guanine bases and tryptophan residues mediated by RuII-TAP complexes is also examined, opening the way to ODN-peptide photocrosslinkings. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim., SCOPUS: ar.j, FLWIN, info:eu-repo/semantics/published

Since the discovery of cisplatin, the search for diagnostic or therapeutic agents based on other metals, has expanded intensively owing to the numerous possibilities offered by coordination chemistry. This mini-review focuses on recent advances in the search for RuII polyazaaromatic complexes of potential interest as molecular tools applied to cellular diagnostics or as specific cellular photo-reagents for future biomedical applications. The interaction of RuII polyazaaromatic complexes with living cells is reported, as well as the photo-reaction mechanisms of photo-oxidizing RuII complexes with nucleic acids. The novel strategies currently developed to improve their reactivity and specificity towards DNA, more particularly in the gene-silencing framework, are also discussed. © 2012 Bentham Science Publishers., info:eu-repo/semantics/published

Les complexes polyazaaromatiques de RuII sont conçus et étudiés pour être exploités dansde nombreux domaines. Dans, le présent travail, nous avons combiné l’utilisation conjointe de cescomplexes et de biomolécules en vue de leur utilisation dans différents domaines liés à la biologie.Les trois premiers chapitres sont consacrés à l’étude de la photoréaction entre les complexes[Ru(TAP)3]2+ et [Ru(TAP)2(phen)]2+ en présence des acides aminés tryptophane et tyrosine. Cesétudes ont permis d’améliorer la compréhension des processus photo-induits entre le complexede RuII et le tryptophane, menant notamment à la mise en évidence d’une réaction de fuite autransfert d’électron en retour entre les deux espèce radicalaires photo-produites. Cette réaction apu être identifiée comme étant le processus de dimérisation de deux unités tryptophanes. Cettedimérisation ainsi que la formation de double photo-adduit impliquant deux tryptophanes et uncomplexe de RuII ont été mises en évidence et étudiées en utilisant un support oligonucléotidiquedouble brin sur lequel sont attachées les espèces réactives.Le quatrième chapitre concerne l’étude d’un conjugué formé entre le complexe de RuII ,[Ru(TAP)2(phen)]2+, et le peptide de transfection TAT. La photoréactivité de cette entité aété examinée et confirmée en présence de l’acide aminé tryptophane et de la base guanine. Pourcette dernière, une étude plus poussée a été réalisée afin de caratériser au mieux l’interactionexistant entre le conjugué Ru-TAT et un oligonucléotide comportant une guanine. Cette étuderassemble des observations expérimentales et une approche théorique par modélisation moléculaire.Le cinquième chapitre consiste en l’étude du comportement photophysique du complexe[Ru(TAP)2(pytz)]2+ sous illumination en présence de la base guanine. Cette étude vise à déterminersi ce complexe possède les qualités d’agent photo-oxydant satisfaisantes pour envisagerson ancrage sur, Doctorat en Sciences, info:eu-repo/semantics/nonPublished

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The photoreaction mechanism of [Ru(TAP)(2)(phen)](2+) and [Ru(TAP)(3)](2+) (TAP = 1,4,5,8-tetraazaphenanthrene) with tryptophan (Trp), N-acetyl-Trp, and Lys-Trp-Lys is examined. The existence of a photoelectron-transfer process from the amino acid unit is demonstrated by laser flash photolysis experiments. The back electron transfer (BET) from the reduced complex to the oxidized amino acid, occurring at the microsecond time scale, corresponds approximately to an equimolecular-bimolecular process; however, it is disturbed by another reaction, originating from the oxidized Trp. Moreover, in competition with the BET, the reduced and oxidized intermediates give rise to an adduct. The latter is clearly detected by gel electrophoresis experiments in denaturing conditions, with a system composed of an oligonucleotide derivatized at the 3' end by the Ru(II)TAP complex and hybridized with the complementary sequence functionalized at the 5' end by the tripeptide Lys-Trp-Lys. Thus, upon illumination, a cross-linking between the two strands is observed, which originates from the presence of a Trp residue., Journal Article, Research Support, Non-U.S. Gov't, SCOPUS: ar.j, info:eu-repo/semantics/published

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