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148 results on '"Tharaud, Mickaël"'

5. Single‐cell determination of iron content in magnetotactic bacteria: implications for the iron biogeochemical cycle

Author

Amor, Matthieu, Tharaud, Mickaël, Gélabert, Alexandre, and Komeili, Arash

Subjects
Microbiology, Biological Sciences, Life Below Water, Environmental Microbiology, Iron, Magnetics, Magnetosomes, Magnetospirillum, Single-Cell Analysis, Evolutionary Biology, Ecology
Abstract

Magnetotactic bacteria (MTB) are ubiquitous aquatic microorganisms that mineralize dissolved iron into intracellular magnetic crystals. After cell death, these crystals are trapped into sediments that remove iron from the soluble pool. MTB may significantly impact the iron biogeochemical cycle, especially in the ocean where dissolved iron limits nitrogen fixation and primary productivity. A thorough assessment of their impact has been hampered by a lack of methodology to measure the amount of, and variability in, their intracellular iron content. We quantified the iron mass contained in single MTB cells of Magnetospirillum magneticum strain AMB-1 using a time-resolved inductively coupled plasma-mass spectrometry methodology. Bacterial iron content depends on the external iron concentration, and reaches a maximum value of ~10-6 ng of iron per cell. From these results, we calculated the flux of dissolved iron incorporation into environmental MTB populations and conclude that MTB may mineralize a significant fraction of dissolved iron into crystals.

Published
2020

8. Collaborative determination of trace element mass fractions and isotope ratios in AQUA-1 drinking water certified reference material

Author

Yeghicheyan, Delphine, Grinberg, Patricia, Alleman, Laurent Y., Belhadj, Moustafa, Causse, Léa, Chmeleff, Jérôme, Cordier, Laure, Djouraev, Irina, Dumoulin, David, Dumont, Jean, Freydier, Rémi, Mariot, Hélène, Cloquet, Christophe, Kumkrong, Paramee, Malet, Bruno, Jeandel, Catherine, Marquet, Aurélie, Riotte, Jean, Tharaud, Mickaël, Billon, Gabriel, Trommetter, Guillaume, Séby, Fabienne, Guihou, Abel, Deschamps, Pierre, and Mester, Zoltan

Published
2021
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15. In Situ Bioconjugation of a Maleimide-Functionalized Ruthenium-Based Photosensitizer to Albumin for Photodynamic Therapy

Author

Vinck, Robin, primary, Dömötör, Orsolya, additional, Karges, Johannes, additional, Jakubaszek, Marta, additional, Seguin, Johanne, additional, Tharaud, Mickaël, additional, Guérineau, Vincent, additional, Cariou, Kevin, additional, Mignet, Nathalie, additional, Enyedy, Éva A., additional, and Gasser, Gilles, additional

Published
2023
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20. Chemical signature of magnetotactic bacteria

Author

Amor, Matthieu, Busigny, Vincent, Durand-Dubief, Mickaël, Tharaud, Mickaël, Ona-Nguema, Georges, Gélabert, Alexandre, Alphandéry, Edouard, Menguy, Nicolas, Benedetti, Marc F., Chebbi, Imène, and Guyot, François

Published
2015

23. In SituBioconjugation of a Maleimide-Functionalized Ruthenium-Based Photosensitizer to Albumin for Photodynamic Therapy

Author

Vinck, Robin, Dömötör, Orsolya, Karges, Johannes, Jakubaszek, Marta, Seguin, Johanne, Tharaud, Mickaël, Guérineau, Vincent, Cariou, Kevin, Mignet, Nathalie, Enyedy, Éva A., and Gasser, Gilles

Abstract

Maleimide-containing prodrugs can quickly and selectively react with circulating serum albumin following their injection in the bloodstream. The drug–albumin complex then benefits from longer blood circulation times and better tumor accumulation. Herein, we have applied this strategy to a previously reported highly phototoxic Ru polypyridyl complex-based photosensitizer to increase its accumulation at the tumor, reduce off-target cytotoxicity, and therefore improve its pharmacological profile. Specifically, two complexes were synthesized bearing a maleimide group: one complex with the maleimide directly incorporated into the bipyridyl ligand, and the other has a hydrophilic linker between the ligand and the maleimide group. Their interaction with albumin was studied in-depth, revealing their ability to efficiently bind both covalently and noncovalently to the plasma protein. A crucial finding is that the maleimide-functionalized complexes exhibited significantly lower cytotoxicity in noncancerous cells under dark conditions compared to the nonfunctionalized complex, which is a highly desirable property for a photosensitizer. The binding to albumin also led to a decrease in the phototoxicity of the Ru bioconjugates in comparison to the nonfunctionalized complex, probably due to a decreased cellular uptake. Unfortunately, this decrease in phototoxicity was not compensated by a dramatic increase in tumor accumulation, as was demonstrated in a tumor-bearing mouse model using inductively coupled plasma mass spectrometry (ICP-MS) studies. Consequently, this study provides valuable insight into the future design of in situalbumin-binding complexes for photodynamic therapy in order to maximize their effectiveness and realize their full potential.

Published
2023
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28. Speciation-Driven Bioavailability in Lagoon Sediments Downstream of Ultramafic Catchments: A Pilot Study on Chromium, Nickel, Iron and Manganese in New Caledonia

Author

Juillot, Farid, primary, Merrot, Pauline, additional, Flipo, Léonore, additional, Tharaud, Mickaël, additional, Viollier, Eric, additional, Noël, Vincent, additional, Le Pape, Pierre, additional, Fernandez, Jean-Michel, additional, Moreton, Benjamin, additional, and Morin, Guillaume, additional

Published
2021
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32. Ruthenium(II) Complex Containing a Redox-Active Semiquinonate Ligand as a Potential Chemotherapeutic Agent: From Synthesis toIn VivoStudies

Author

Notaro, Anna, primary, Frei, Angelo, additional, Rubbiani, Riccardo, additional, Jakubaszek, Marta, additional, Basu, Uttara, additional, Koch, Severin, additional, Mari, Cristina, additional, Dotou, Mazzarine, additional, Blacque, Olivier, additional, Gouyon, Jérémie, additional, Bedioui, Fethi, additional, Rotthowe, Nils, additional, Winter, Rainer F., additional, Goud, Bruno, additional, Ferrari, Stefano, additional, Tharaud, Mickaël, additional, Řezáčová, Martina, additional, Humajová, Jana, additional, Tomšík, Pavel, additional, and Gasser, Gilles, additional

Published
2020
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33. Rationally Designed Long-Wavelength Absorbing Ru(II) Polypyridyl Complexes as Photosensitizers for Photodynamic Therapy

Author

Karges, Johannes, Heinemann, Franz, Jakubaszek, Marta, Maschietto, Federica, Subecz, Chloé, Dotou, Mazzarine, Vinck, Robin, Blacque, Olivier; https://orcid.org/0000-0001-9857-4042, Tharaud, Mickaël, Goud, Bruno, Viñuelas Zahínos, Emilio; https://orcid.org/0000-0003-0634-1829, Spingler, Bernhard; https://orcid.org/0000-0003-3402-2016, Ciofini, Ilaria, Gasser, Gilles; https://orcid.org/0000-0002-4244-5097, Karges, Johannes, Heinemann, Franz, Jakubaszek, Marta, Maschietto, Federica, Subecz, Chloé, Dotou, Mazzarine, Vinck, Robin, Blacque, Olivier; https://orcid.org/0000-0001-9857-4042, Tharaud, Mickaël, Goud, Bruno, Viñuelas Zahínos, Emilio; https://orcid.org/0000-0003-0634-1829, Spingler, Bernhard; https://orcid.org/0000-0003-3402-2016, Ciofini, Ilaria, and Gasser, Gilles; https://orcid.org/0000-0002-4244-5097

Abstract

The utilization of photodynamic therapy (PDT) for the treatment of various types of cancer has gained increasing attention over the last decades. Despite the clinical success of approved photosensitizers (PSs), their application is sometimes limited due to poor water solubility, aggregation, photodegradation, and slow clearance from the body. To overcome these drawbacks, research efforts are devoted toward the development of metal complexes and especially Ru(II) polypyridine complexes based on their attractive photophysical and biological properties. Despite the recent research developments, the vast majority of complexes utilize blue or UV-A light to obtain a PDT effect, limiting the penetration depth inside tissues and, therefore, the possibility to treat deep-seated or large tumors. To circumvent these drawbacks, we present the first example of a DFT guided search for efficient PDT PSs with a substantial spectral red shift toward the biological spectral window. Thanks to this design, we have unveiled a Ru(II) polypyridine complex that causes phototoxicity in the very low micromolar to nanomolar range at clinically relevant 595 nm, in monolayer cells as well as in 3D multicellular tumor spheroids.

Published
2020

34. A Maltol‐Containing Ruthenium Polypyridyl Complex as a Potential Anticancer Agent

Author

Notaro, Anna, primary, Jakubaszek, Marta, additional, Koch, Severin, additional, Rubbiani, Riccardo, additional, Dömötör, Orsolya, additional, Enyedy, Éva A., additional, Dotou, Mazzarine, additional, Bedioui, Fethi, additional, Tharaud, Mickaël, additional, Goud, Bruno, additional, Ferrari, Stefano, additional, Alessio, Enzo, additional, and Gasser, Gilles, additional

Published
2020
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36. Rationally Designed Long-Wavelength Absorbing Ru(II) Polypyridyl Complexes as Photosensitizers for Photodynamic Therapy

Author

Karges, Johannes, primary, Heinemann, Franz, additional, Jakubaszek, Marta, additional, Maschietto, Federica, additional, Subecz, Chloé, additional, Dotou, Mazzarine, additional, Vinck, Robin, additional, Blacque, Olivier, additional, Tharaud, Mickaël, additional, Goud, Bruno, additional, Viñuelas Zahı́nos, Emilio, additional, Spingler, Bernhard, additional, Ciofini, Ilaria, additional, and Gasser, Gilles, additional

Published
2020
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38. Increasing the Cytotoxicity of Ru(II) Polypyridyl Complexes by Tuning the Electronic Structure of Dioxo Ligands

Author

Notaro, Anna, primary, Jakubaszek, Marta, additional, Rotthowe, Nils, additional, Maschietto, Federica, additional, Vinck, Robin, additional, Felder, Patrick S., additional, Goud, Bruno, additional, Tharaud, Mickaël, additional, Ciofini, Ilaria, additional, Bedioui, Fethi, additional, Winter, Rainer F., additional, and Gasser, Gilles, additional

Published
2020
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39. Ruthenium-initiated polymerization of lactide: a route to remarkable cellular uptake for photodynamic therapy of cancer

Author

Soliman, Nancy, primary, McKenzie, Luke K., additional, Karges, Johannes, additional, Bertrand, Emilie, additional, Tharaud, Mickaël, additional, Jakubaszek, Marta, additional, Guérineau, Vincent, additional, Goud, Bruno, additional, Hollenstein, Marcel, additional, Gasser, Gilles, additional, and Thomas, Christophe M., additional

Published
2020
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40. Rationally Designed Long-Wavelength Absorbing Ru(II) Polypyridyl Complexes as Photosensitizers for Photodynamic Therapy

Author

Karges, Johannes, primary, Heinemann, Franz, primary, Jakubaszek, Marta, primary, Maschietto, Federica, primary, Subecz, Chloé, primary, Dotou, Mazzarine, primary, Blacque, Olivier, primary, Tharaud, Mickaël, primary, Goud, Bruno, primary, Vinuelas Zahinos, Emilio, primary, Spingler, Bernhard, primary, Ciofini, Ilaria, primary, and Gasser, Gilles, primary

Published
2019
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43. Encapsulation of a Ruthenium(II) Complex in Polylactide Nanoparticles: A Route to Remarkable Cellular Uptake for Photodynamic Therapy of Cancer

Author

Soliman, Nancy, primary, McKenzie, Luke K., primary, Karges, Johannes, primary, Bertrand, Emilie, primary, Tharaud, Mickaël, primary, Jakubaszek, Marta, primary, Guérineau, Vincent, primary, Goud, Bruno, primary, Hollenstein, Marcel, primary, Gasser, Gilles, primary, and Thomas, Christophe M., primary

Published
2019
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44. A Ruthenium(II) Complex Containing a Redox-Active Semiquinonate Ligand as Potential Chemotherapeutic Agent: From Synthesis to In Vivo Studies

Author

Notaro, Anna, primary, Frei, Angelo, additional, Rubbiani, Riccardo, additional, Jakubaszek, Marta, additional, Basu, Uttara, additional, Koch, Severin, additional, Mari, Cristina, additional, Dotou, Mazzarine, additional, Blacque, Olivier, additional, Gouyon, Jérémie, additional, Bedioui, Fethi, additional, Rotthowe, Nils, additional, Winter, Rainer F., additional, Goud, Bruno, additional, Ferrari, Stefano, additional, Tharaud, Mickaël, additional, Řezáčová, Martina, additional, Humajová, Jana, additional, Tomšík, Pavel, additional, and Gasser, Gilles, additional

Published
2019
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47. A Multi‐action and Multi‐target RuII–PtIV Conjugate Combining Cancer‐Activated Chemotherapy and Photodynamic Therapy to Overcome Drug Resistant Cancers.

Author

Karges, Johannes, Yempala, Thirumal, Tharaud, Mickaël, Gibson, Dan, and Gasser, Gilles

Subjects
PHOTODYNAMIC therapy, PLATINUM, DRUG therapy, PRODRUGS, CANCER chemotherapy, CANCER, CANCER cells
Abstract

PtII complexes are commonly used to treat cancer. To reduce their side effects and improve their pharmacological properties, PtIV complexes are being developed as prodrug candidates that are activated by reduction in cancer cells. Concomitantly, RuII polypyridine complexes have gained much attention as photosensitizers for use in photodynamic therapy due to their attractive characteristics. In this article, a novel PtIV–RuII conjugate, which combines cancer activated chemotherapy with PDT, is presented. Upon entering the cancer cell, the PtIV centre is reduced to PtII and the axial ligands including the RuII complex and phenylbutyrate are released. As each component has its individual targets, the conjugate exerts a multi‐target and multi‐action effect with (photo‐)cytotoxicity values upon irradiation up to 595 nm in the low nanomolar range in various (drug resistant) 2D monolayer cancer cells and 3D multicellular tumour spheroids. [ABSTRACT FROM AUTHOR]

Published
2020
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48. Interlaboratory comparison study on Au NPs -final report

Author

Meermann, Björn, Kaegi, Ralf, Cornelis, Geert, Philippe, Allan, Domingos, Rute, Sivry, Yann, Cohen-Ofri, Ilit, Tharaud, Mickaël, Troester, Martin, v.d. Kammer, Frank, Wagner, Stephan, Bucheli, Thomas, Gogos, Alexander, Ciglenečki, Irena, Marguš, Marija, Serchi, Tommaso, and Cambier, Sebastien

Subjects
nanoparticles, Au NPs, interlaboratory comparison study
Abstract

An interlaboratory comparison study on the analysis of gold nanoparticles (AuNPs) among members of the working group 4 (engineered nanomaterials) (http://www.norman-network.net/?q=node/54) within the NORMAN network and members of the COST Action ES1205 ENTER (www.es1205.eu) was conducted. The nanomaterials under investigation were gold nanoparticle suspensions (Au NP) with Au NP sizes of 10, 50 and 250 nm. Three monomodal samples and two mixtures (bi- and trimodal) out of the single sized Au NP standards were prepared as (artificial) samples and sent to the attendees for analysis. The aim of the interlaboratory test was to investigate, if comparable data in terms of “easy to handle nanomaterials” and different analytical techniques can be obtained and, if the current EU definition recommendation for the term “nanomaterial” is implementable. Each attendee was free to decide which sample preparation protocol and technique to apply - no strict rules were defined. Upon a previous survey by means of a questionnaire the available lab equipment of the attendees was assessed. Also based on accessible lab equipment it was asked for following parameters to be analyzed: i) total concentration of gold in each sample, ii) size distribution of Au NPs in the monomodal samples and in the mixtures, iii) based on the data obtained, decision whether the mixture can be allocated to nanomaterial or not according to the EU definition recommendation [1]. This report compiles the obtained results and findings are discussed in a comparative manner. Pros and cons of the applied techniques are highlighted.

Published
2016

50. Ruthenium(II) Complex Containing a Redox-Active Semiquinonate Ligand as a Potential Chemotherapeutic Agent: From Synthesis to In VivoStudies

Author

Notaro, Anna, Frei, Angelo, Rubbiani, Riccardo, Jakubaszek, Marta, Basu, Uttara, Koch, Severin, Mari, Cristina, Dotou, Mazzarine, Blacque, Olivier, Gouyon, Jérémie, Bedioui, Fethi, Rotthowe, Nils, Winter, Rainer F., Goud, Bruno, Ferrari, Stefano, Tharaud, Mickaël, Řezáčová, Martina, Humajová, Jana, Tomšík, Pavel, and Gasser, Gilles

Abstract

Chemotherapy remains one of the dominant treatments to cure cancer. However, due to the many inherent drawbacks, there is a search for new chemotherapeutic drugs. Many classes of compounds have been investigated over the years to discover new targets and synergistic mechanisms of action including multicellular targets. In this work, we designed a new chemotherapeutic drug candidate against cancer, namely, [Ru(DIP)2(sq)](PF6)(Ru-sq) (DIP = 4,7-diphenyl-1,10-phenanthroline; sq = semiquinonate ligand). The aim was to combine the great potential expressed by Ru(II) polypyridyl complexes and the singular redox and biological properties associated with the catecholate moiety. Experimental evidence (e.g., X-ray crystallography, electron paramagnetic resonance, electrochemistry) demonstrates that the semiquinonate is the preferred oxidation state of the dioxo ligand in this complex. The biological activity of Ru-sqwas then scrutinized in vitroand in vivo, and the results highlight the promising potential of this complex as a chemotherapeutic agent against cancer.

Published
2020
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