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Using an Untargeted Metabolomics Approach to Identify Salivary Metabolites in Women with Breast Cancer
Laboratoire Sciences Analytiques Bioanalytiques et Miniaturisation - Daniele Xavier Assad ,Ana Carolina Acevedo, Elisa Cançado Porto Mascarenhas, Ana Gabriela Costa Normando,Valérie Pichon,Helene Chardin,Eliete Neves Silva Guerra and Audrey Combes
Metabolites - 10(12) 1727-1751 - - 2020
Metabolic alterations are a hallmark of the malignant transformation in cancer cells, which is characterized by multiple changes in metabolic pathways that are linked to macromolecule synthesis. This study aimed to explore whether salivary metabolites could help discriminate between breast cancer patients and healthy controls. Saliva samples from 23 breast cancer patients and 35 healthy controls were subjected to untargeted metabolomics using liquid chromatography-quadrupole time-of-flight mass spectrometry and a bioinformatics tool (XCMS Online), which revealed 534 compounds, characterized by their retention time in reverse-phase liquid chromatography and by the m/z ratio detected, that were shared by the two groups. Using the METLIN database, 31 compounds that were upregulated in the breast cancer group (p < 0.05) were identified, including seven oligopeptides and six glycerophospholipids (PG14:2, PA32:1, PS28:0, PS40:6, PI31:1, and PI38:7). In addition, pre-treatment and post-treatment saliva samples were analyzed for 10 patients who experienced at least a partial response to their treatment. In these patients, three peptides and PG14:2 were upregulated before but not after treatment. The area under the curve, sensitivity, and specificity for PG14:2 was 0.7329, 65.22%, and 77.14%, respectively. These results provide new information regarding the salivary metabolite profiles of breast cancer patients, which may be useful biomarkers. View Full-Text

Synthesis and characterization of molecularly imprinted polymers for the selective extraction of oxazepam from complex environmental and biological samples
Laboratoire Sciences Analytiques Bioanalytiques et Miniaturisation - Daniele Xavier Assad Elisa Cançado Porto Mascarenhas Ana Gabriela Costa Normando Hélène Chardin Gustavo Barcelos Barra Riccardo Pratesi Yanna Karla De Medeiros Nóbrega Ana Carolina Acevedo Eliete Neves Silva Guerra
Molecular and Clinical Oncology - 155-161 - - 2020
The early detection of breast cancer enables the use of less aggressive treatment and increases patient survival. The transmembrane glycoprotein mucin 1, which is also known as cancer antigen 15‑3 (CA15‑3), is aberrantly glycosylated and overexpressed in a variety of epithelial cancers, and serves a crucial role in the progression of the disease. CA15‑3 is currently used as a marker of breast cancer. In the present study, CA15‑3 concentrations in saliva and blood of patients with breast cancer were evaluated to test new assays to detect salivary CA15‑3 in addition to ELISA and its diagnostic value. To the best of our knowledge, there are no previous reports of the use of chemiluminescence assay (CLIA) and electrochemiluminescence assay (ECLIA) in saliva. Saliva and blood were collected on the same day from patients with breast cancer (n=26) and healthy controls (n=28). For each subject, the level of serum CA15‑3 was measured using ECLIA, and the level of salivary CA15‑3 was measured using ECLIA, CLIA and enzyme‑linked immunosorbent assay (ELISA). ELISA and CLIA were able to detect CA15‑3 in saliva; however, ECLIA could not detect salivary CA15‑3. There was no significant difference between the mean serum and salivary CA15‑3 levels in patients with breast cancer or healthy controls. The levels of CA15‑3 were highest for luminal breast cancer subtypes and stage IV cases. A moderate correlation was observed between salivary and serum CA15‑3 levels as measured by ELISA in breast cancer patients (r=0.56; P=0.0047). The results demonstrated that ECLIA was not a good method to detect salivary CA15‑3, although it is the gold standard for detecting serum CA15‑3. The presence of CA15‑3 in saliva was confirmed, and this will be useful in future research. Further investigations are necessary to confirm the ability to detect salivary CA15‑3 and its correlation with serum CA15‑3.
How high resolution mass spectrometry can help for the accurate quantification of difficult fragrance allergens
Laboratoire Sciences Analytiques Bioanalytiques et Miniaturisation - Pierre‐Alain Remy, C. Pérès, J. Dugay, E. Corbi, Nathalie David, J. Vial
Flavour and Fragrance Journal - 36(1) - DOI:10.1002/ffj.3639 - 2020
Two high‐resolution mass spectrometers (HRMS) with different analyzer technology, Orbitrap and hybrid quadrupole time‐of‐flight (QTOF), were compared with a low‐resolution mass spectrometer, quadrupole, to analyse a set of 35 difficult allergens. These difficult allergens are commonly coeluted fragrance allergens with matrix compounds, using standard gas chromatography‐mass spectrometer conditions, from the extended list of the Scientific Committee on Consumer Safety (SCCS). Although the fundamental role of chromatographic separation has been demonstrated many times, the aim of this work is to demonstrate the benefits of high‐resolution. The added value of high‐resolution was illustrated in both a qualitative and a quantitative way. For qualitative aspect, the high resolution extracted ion signals of these two detectors were compared with the low‐resolution extracted ion signals. About 50% of the coeluted cases observed with the low‐resolution detector are easily resolved by the two high‐resolution detectors. For the quantitative aspect, an accuracy profile methodology and a performance metric were used to propose an overall evaluation. The Orbitrap mass spectrometer demonstrated a better overall performance, while the QTOF presented similar or even lower quantification performances than the quadrupole on the set of analysed fragrance
Impact of the Oil Matrix on Anionic and Nonionic Surfactant Separation Using Ultra-High-Performance Liquid Chromatography Hyphenated to High-Resolution Mass Spectrometry
Laboratoire Sciences Analytiques Bioanalytiques et Miniaturisation - Alizée Dufour, Didier Thiébaut, Matthieu Loriau, Leticia Ligiero, and Jérôme Vial
American Chemical Society - 34(11) 13943–13953 - - 2020
For the first time, to our knowledge, anionic and nonionic surfactants were analyzed in an oil matrix by ultra-high-performance liquid chromatography hyphenated to high-resolution mass spectrometry (UHPLC-HRMS). The feasibility of this analysis was studied using synthetic mixtures of surfactants prepared in water (quality controls), binary THF/toluene 50/50 v/v (surfactant + THF/toluene), and binary THF/toluene containing 1 and 10% crude oil (Crude1% and Crude10%). These compositions were chosen in order to be as close as possible to petroleum related samples to be investigated in the future. Analyses were carried out by UHPLC methods using both reverse phase and anion-exchange mechanisms with a mixed mode column. Despite the complexity of the oil matrix and the presence of organic solvents used for dilution, the retention times of the surfactants were not affected whatever the concentration of crude oil present in the sample. Nevertheless, a significant matrix effect caused a loss of signal when the concentration of oil reached 10% in mass. For the analysis of samples with this crude oil concentration range, it would be advisable to dilute the sample.

Performance evaluation of a MIP for the MISPE-LC determination of p-[18F]MPPF and a potential metabolite in human plasma
Laboratoire Spectrométrie de masse biologique et protéomique - F.Lecomte J.Aerts Plenevaux .Defraiteur. Chapuis-Hugonc. Rozetd. Chiape. Luxen. Pichon, Ph.Huberta C.Huberta
J Pharm Biomed Anal - 180 113015 - - 2020
Within the family of serotonin (5-HT) receptors, the 5-HT1A subtype is particularly interesting as it may be involved in various physiological processes or psychological disorders. The p-[18F]MPPF, a highly selective 5-HT1A antagonist, is used for in vivo studies in human or animal by means of positron emission tomography (PET) [1].
In order to selectively extract p-[18F]MPPF and its main metabolites from plasma, molecularly imprinted polymer (MIP) was prepared against these compounds by using the p-MPPF as template. For the control of the selectivity, non-imprinted polymer (NIP) was also synthesized without template. The MIP sorbent, packed in disposable extraction cartridges (DECs), was then evaluated as molecularly imprinted solid-phase extraction (MISPE) prior to the LC determination. The conditions of extraction were evaluated in order to obtain the highest selective retention of the p-[18F]MPPF and its metabolites on this MIP. The MIP selectivity was exploited in the loading and washing steps by adjusting the pH of plasma samples at a suitable value and by selecting mixtures for the washing step to limit the contribution of non-specific interactions. Other important parameters involved in the conditioning and elution steps were also studied. Finally, a pre-validation was carried out with optimal extraction conditions to demonstrate the performance of this MISPE-LC method as a generic method in the context of evaluation of new MISPE for p-[18F]MPPF and its potential for metabolites extraction from human plasma.
S-nitrosylation affects TRAP1 structure and ATPase activity and modulates cell response to apoptotic stimuli
Laboratoire Spectrométrie de masse biologique et protéomique - Fiorella Faienza, Matteo Lambrughi, Salvatore Rizza, Chiara Pecorari, Paola Giglio, Juan Salamanca Viloria, Maria Francesca Allega, Giovanni Chiappetta, Joëlle Vinh, Francesca Pacello, Andrea Battistoni, Andrea Rasola, Elena Papaleo, Giuseppe Filomeni
bioRxiv - - doi: 10.1016/j.bcp.2020.113869 - 2020
The mitochondrial chaperone TRAP1 has been involved in several mitochondrial functions, and modulation of its expression/activity has been suggested to play a role in the metabolic reprogramming distinctive of cancer cells. TRAP1 posttranslational modifications, i.e. phosphorylation, can modify its capability to bind to different client proteins and modulate its oncogenic activity. Recently, it has been also demonstrated that TRAP1 is S-nitrosylated at Cys501, a redox modification associated with its degradation via the proteasome. Here we report molecular dynamics simulations of TRAP1, together with analysis of long-range structural communication, providing a model according to which Cys501 S-nitrosylation induces conformational changes to distal sites in the structure of the protein. The modification is also predicted to alter open and closing motions for the chaperone function. By means of colorimetric assays and site directed mutagenesis aimed at generating C501S variant, we also experimentally confirmed that selective S-nitrosylation of Cys501 decreases ATPase activity of recombinant TRAP1. Coherently, C501S mutant was more active and conferred protection to cell death induced by staurosporine. Overall, our results provide the first in silico, in vitro and cellular evidence of the relevance of Cys501 S-nitrosylation in TRAP1 biology.
The zoonotic pathogen Leptospira interrogans mitigates environmental stress through cyclic-di-GMP-controlled biofilm production
Laboratoire Spectrométrie de masse biologique et protéomique - Thibeaux R, Soupé-Gilbert ME, Kainiu M, Girault D, Bierque E, Fernandes J, Bähre H, Douyère A, Eskenazi N, Vinh J, Picardeau M, Goarant C
NPJ Biofilms Microbiomes - 6(1) 24 - DOI [DOI] – 10.1038/s41522-020-0134-1 - 2020
The zoonotic bacterium Leptospira interrogans is the aetiological agent of leptospirosis, a re-emerging infectious disease that is a growing public health concern. Most human cases of leptospirosis result from environmental infection. Biofilm formation and its contribution to the persistence of virulent leptospires in the environment or in the host have scarcely been addressed. Here, we examined spatial and time-domain changes in biofilm production by L. interrogans. Our observations showed that biofilm formation in L. interrogans is a highly dynamic process and leads to a polarized architecture. We notably found that the biofilm matrix is composed of extracellular DNA, which enhances the biofilm’s cohesiveness. By studying L. interrogans mutants with defective diguanylate cyclase and phosphodiesterase genes, we show that biofilm production is regulated by intracellular levels of bis-(3′-5′)-cyclic dimeric guanosine monophosphate (c-di-GMP) and underpins the bacterium’s ability to withstand a wide variety of simulated environmental stresses. Our present results show how the c-di-GMP pathway regulates biofilm formation by L. interrogans, provide insights into the environmental persistence of L. interrogans and, more generally, highlight leptospirosis as an environment-borne threat to human health.
On-Chip Sample Preparation Using a ChipFilter Coupled to NanoLC-MS/MS for Bottom-Up Proteomics
Laboratoire Spectrométrie de masse biologique et protéomique - Massamba M Ndiaye, Ha Phuong Ta, Giovanni Chiappetta, Joëlle Vinh
J Proteome Res - 19(7) 2654-2663 - DOI: 10.1021/acs.jproteome.9b00832 - 2020
Sample preparation is a crucial step in bottom-up proteomics. Analytical performances of bottom-up proteomics can be improved by the miniaturization of sample preparation. Many microfluidic devices have been designed in the field of proteomics, but many of them are not capable of handling complex samples and do not integrate the processing and digestion steps. We propose a ChipFilter Proteolysis (CFP) microfluidic device as a proteomics reactor for the miniaturization of protein sample processing and digestion steps, whose design is closely related to the experimental setup of filter-aided sample processing, even if no denaturing surfactant is required. The microchip has two reaction chambers of 0.6 μL volume separated by a protein filtration membrane in regenerated cellulose (10kD cutoff) that will concentrate or retain large polypeptides and will release small molecules. Cell lysis, protein concentration, and rapid chemical or enzymatic treatment can be performed in the ChipFilter. Complex proteomic samples like yeast protein extract or whole human cells proteome have been successfully analyzed with our microchip. Compared with the membrane-based commercial ultracentrifugation cartridge, our microfluidic device offered a better proteome coverage with 10 times less starting material and 8 times faster protocol duration.
Peptides Derived From Insulin Granule Proteins Are Targeted by CD8+ T Cells Across MHC Class I Restrictions in Humans and NOD Mice
Laboratoire Spectrométrie de masse biologique et protéomique - Marie Eliane Azoury, Mahmoud Tarayrah, Georgia Afonso, Aurore Pais, Maikel L. Colli, Claire Maillard, Cassandra Lavaud, Laure Alexandre-Heymann, Sergio Gonzalez-Duque, Yann Verdier4, Joelle Vinh, Sheena Pinto, Soren Buus, Danièle Dubois-L
Diabetes - 69(12) 2678-2690 - - 2020
The antigenic peptides processed by β-cells and presented through surface HLA class I molecules are poorly characterized. Each HLA variant (e.g., the most common being HLA-A2 and HLA-A3) carries some peptide-binding specificity. Hence, features that, despite these specificities, remain shared across variants may reveal factors favoring β-cell immunogenicity. Building on our previous description of the HLA-A2/A3 peptidome of β-cells, we analyzed the HLA-A3–restricted peptides targeted by circulating CD8+ T cells. Several peptides were recognized by CD8+ T cells within a narrow frequency (1–50/106), which was similar in donors with and without type 1 diabetes and harbored variable effector/memory fractions. These epitopes could be classified as conventional peptides or neoepitopes, generated either via peptide cis-splicing or mRNA splicing (e.g., secretogranin-5 [SCG5]–009). As reported for HLA-A2–restricted peptides, several epitopes originated from β-cell granule proteins (e.g., SCG3, SCG5, and urocortin-3). Similarly, H-2Kd–restricted CD8+ T cells recognizing the murine orthologs of SCG5, urocortin-3, and proconvertase-2 infiltrated the islets of NOD mice and transferred diabetes into NOD/scid recipients. The finding of granule proteins targeted in both humans and NOD mice supports their disease relevance and identifies the insulin granule as a rich source of epitopes, possibly reflecting its impaired processing in type 1 diabetes
Deciphering shell proteome within different Baltic populations of mytilid mussels illustrates important local variability and potential consequences in the context of changing marine conditions
Laboratoire Spectrométrie de masse biologique et protéomique - JaisonArivalagan, Benjamin Marie, Giovanni Chiappetta, Joëlle Vinh, Xavier Gallet, Matthieu Lebon Saloua M'Zoudi Philippe Dubois Sophie Berland Arul Marie
ELSEVIER - 745 140878 - - 2020
Molluscs defend themselves against predation and environmental stressors through the possession of mineralized shells. Mussels are widely used to predict the effects of abiotic factors such as salinity and pH on marine calcifiers in the context of changing ocean conditions. Shell matrix proteins are part of the molecular control regulating the biomineralization processes underpinning shell production. Under changing environmental conditions, differential expression of these proteins leads to the phenotypic plasticity of shells seen in many mollusc species. Low salinity decreases the availability of calcium and inorganic carbon in seawater and consequently energetic constraints often lead to thin, small and fragile shells in Mytilid mussels inhabiting Baltic Sea. To understand how the modulation of shell matrix proteins alters biomineralization, we compared the shell proteomes of mussels living under full marine conditions in the North Sea to those living in the low saline Baltic Sea. Modulation of proteins comprising the Mytilus biomineralization tool kit is observed. These data showed a relative increase in chitin related proteins, decrease in SD-rich, GA-rich shell matrix proteins indicating that altered protein scaffolding and mineral nucleation lead to impaired shell microstructures influencing shell resistance in Baltic Mytilid mussels. Interestingly, proteins with immunity domains in the shell matrix are also found to be modulated. Shell traits such as periostracum thickness, organic content and fracture resistance qualitatively correlates with the modulation of SMPs in Mytilid mussels providing key insights into control of biomineralization at molecular level in the context of changing marine conditions.
Development of Immobilized Enzyme Reactors for the characterization of the glycosylation heterogeneity of a protein
Laboratoire Spectrométrie de masse biologique et protéomique - Stan Perchepied, Nicolas Eskenazi, Chiara Giangrande, Julien Camperi, Thierry Fournier, Joëlle Vinh, Nathalie Delaunay, Valérie Pichon
Talanta - 209 120568 - - 2020
The mapping of post-translational modifications (PTMs) of proteins can be addressed by bottom-up proteomics strategy using proteases to achieve the enzymatic digestion of the biomolecule. Glycosylation is one of the most challenging PTM to characterize due to its large structural heterogeneity. In this work, two Immobilized Enzyme Reactors (IMERs) based on trypsin and pepsin protease were used for the first time to fasten and improve the reliability of the specific mapping of the N-glycosylation heterogeneity of glycoproteins. The performance of the supports was evaluated with the digestion of human Chorionic Gonadotropin hormone (hCG), a glycoprotein characterized by four N- and four O-glycosylation sites, prior to the analysis of the digests by nanoliquid chromatography coupled to tandem mass spectrometry (nanoLC-MS/MS). Firstly, the repeatability of the nanoLC-MS/MS was evaluated and a method to control the identification of the identified glycans was developed to validate them regarding the retention time of glycopeptides in reversed phase nanoLC separation. The repeatability of the digestion with trypsin-based IMER was evaluated on the same hCG batch and on three independent batches with common located glycans up to 75%. Then, the performance of the IMER digestions was compared to in-solution digestions to evaluate the qualitative mapping of the glycosylation. It has given rise to 42 out of 45 common glycans between both digestions modes. For the first time, the complementarity of trypsin and pepsin was illustrated for the glycosylation mapping as trypsin led to identifications on 2 out of 4 glycosylation site while pepsin was informative on the 4 glycosylation site. The potential of IMERs for the study of the glycosylation of a protein was illustrated with the comparison of two hCG-based drugs, Ovitrelle® and Pregnyl
Characterization of home-made graphite/PDMS microband electrodes for amperometric detection in an original reusable glass-NOA®-PDMS electrophoretic microdevice
Laboratoire Synthèse Electrochimie Imagerie et Systèmes Analytiques - J.Gouyon F.d’Orlyé S.Griveau F.Bedioui A.Varenne
Electrochimica Acta - 329 135164 - - 2020
A new dismountable and reusable microchip for electrophoretic separation coupled to amperometric detection was developed. For this purpose, a new home made three-microbands electrode system was developed and microfabricated based on screen-printing for the inclusion of graphite/polydimethylsiloxane (C-PDMS) composite in microchannels down to 30 μm width. The composition of the composite as well as the fabrication methodology were optimized for an easy handling and an optimized electrochemical behavior. The electrochemical characterization of this composite material was first performed in bulk format (disc-shaped electrode, 6 mm diameter). It was then transposed to the micrometric scale for its integration in an original glass-NOA81®-PDMS microfluidic device allowing for reversible sealing. The microband electrodes were characterized by scanning electron microcopy and cyclic voltammetry, illustrating a good control of the microelectrode width. Then, the analytical performances of the C-PDMS composite microelectrodes were evaluated using Ru(NH3)63+ and FcMeOH as model electroactive molecules. The electrophoretic separation and quantitation of Ru(NH3)63+ were then performed in a background electrolyte made of hydrochloric acid and sodium chloride, leading to a LOD and a LOQ of 3.4 μmol L−1 and 11.3 μmol L−1, respectively. The re-openable NOA-based microdevice permits to regenerate the electrode surface by simply repositioning the microband on a new spot, allowing for robust analysis in a reusable system.
Hydrogel Matrix-Grafted Impedimetric Aptasensors for the Detection of Diclofenac
Laboratoire Synthèse Electrochimie Imagerie et Systèmes Analytiques - G. S. Kassahun, S. Griveau, S. Juillard, J. Champavert, A. Ringuedé, B. Bresson, Y. Tran*, F. Bedioui, and C. Slim
Langmuir - 36(4) 827–836 - - 2020
Driven by the growing concern about the release of untreated emerging pollutants and the need for determining small amounts of these pollutants present in the environment, novel biosensors dedicated to molecular recognition are developed. We have designed biosensors using a novel class of grafted polymers, surface-attached hydrogel thin films, on conductive transducers as a biocompatible matrix for biomolecule immobilization. We showed that they can be dedicated to the molecular recognition of diclofenac (DCL). The immobilization of the aptamer onto surface-attached hydrogel thin films by covalent attachment provides a biodegradable shelter, providing the aptamer with excellent environments to preserve its active and functional structure while allowing the detection of DCL. The grafting of the aptamer is obtained using the formation of amide bonds via the activation of carboxylic acid groups of the poly(acrylic acid) hydrogel thin film. For improved sensitivity and higher stability of the sensor, a high density of the immobilized aptamer is enabled. The aptamer-modified electrode was then incubated with DCL solutions at different concentrations. The performances of the aptasensor were investigated by electrochemical impedance spectroscopy. The change in charge-transfer resistance was found to be linear with DCL concentration in the 30 pM to 1 μM range. The detection limit was calculated to be 0.02 nM. The improvement of the limit of detection can be mainly attributed to the three-dimensional environment of the hydrogel matrix which improves the grafting density of the aptamer and the affinity of the aptamer to DCL.
Speciation and quantitation of precious metals in model acidic leach liquors, theoretical and practical aspects of recycling
Laboratoire Synthèse Electrochimie Imagerie et Systèmes Analytiques - Jérémie Gouyon, Fanny d’Orlyé, Julia Zimmerman, Sophie Griveau, Fethi Bedioui & Anne Varenne
Analytical and Bioanalytical Chemistry volume - 412 4595–4608 - - 2020
Waste printed circuit boards are a major source of strategic materials such as platinum group metals since they are used for the fabrication of technological devices, such as hard drive discs, capacitors, and diodes. Because of the high cost of platinum, palladium, and gold (> 25 k€/kg), an economic and environmental challenge is their recycling from printed circuit boards that represent around 2% weight of electronic equipment. Hydrometallurgical treatments allow the recovery of these metals in solution, with a high recovery rate for a leaching liquor made of thiourea in hydrochloric acid. So as to develop an efficient recycling process from this leach liquor, one requires the speciation of these strategic metals, as well as their extraction and quantitation in the mixture. For this purpose, platinum, palladium, and gold were dissolved in model leach liquors made of hydrochloric acid and thiourea at low concentration. The identification of metal complexes was determined as a function of thiourea concentration (between 10 μmol/L and 10 mmol/L) by the combination of UV-visible spectrometry, cyclic voltammetry, and for the first time capillary electrophoresis. The electrokinetic method was then applied for the quantitation of trace metal analyses in leach samples from waste printed circuit boards reprocessing, demonstrating its applicability for industrializable recycling applications.

Reversible microfluidics device for precious metal electrodeposition and depletion yield studies
Laboratoire Synthèse Electrochimie Imagerie et Systèmes Analytiques - Jérémie Gouyon Fanny d’Orlyé Craig Simon Sophie Griveau Catherine Sella Laurent Thouin Fethi Bediouia Anne Varenne
Electrochimica Acta - 352 136474 - - 2020
A new low-cost reversible Glass-NOA®-PDMS microfluidic device was designed for the study of recovery yield of precious metals present in acid media mimicking leach liquors for long-term recycling objectives. It offers the unique advantage of allowing easy washing of the microchannel and renewal of the electrode surface by simply repositioning the microband electrodes which allows this type of device to have a relatively much longer lifespan than irreversibly closed ones. It consists in a re-useable microchip with four graphite microbands electrodes, prepared by screen printing, to set-up an original amperometric device for both depletion and yield quantification. One upstream working electrode is devoted to the depletion of the metallic ions through their electrolysis by electrodeposition while the second downstream working microelectrode is used as real-time detection electrode to evaluate the depletion efficiency. The dimensions of the depletion electrode and of the channel were optimized thanks to numerical simulations for a given range of flow velocities. First, the performances of the device were assessed experimentally according to flow rate and applied potential under continuous flow, and then compared to theoretical predictions using an electrochemical probe, ferrocenemethanol. The proof of concept was then demonstrated for precious metal, by electroreduction of Pd(II) and Au(III) from acidic leach liquors under continuous flow, with a depletion yield of up to 89% and 71% respectively.
Multiple Zones Modification of Open Off-Stoichiometry Thiol-Ene Microchannel by Aptamers: A Methodological Study & A Proof of Concept
Laboratoire Synthèse Electrochimie Imagerie et Systèmes Analytiques - Samantha Bourg, Fanny d’Orlyé, Sophie Griveau, Fethi Bedioui, Jose Alberto Fracassi da Silva, andAnne Varenne.
Electrochimica Acta - 8(2) 24 - - 2020
Off-stoichiometry thiol-ene polymer (OSTE) is an emerging thermoset with interesting properties for the development of lab-on-a-chip (LOAC), such as easy microfabrication process, suitable surface chemistry for modification and UV-transparency. One of the challenges for LOAC development is the integration of all the analytical steps in one microchannel, and particularly, trace level analytes extraction/preconcentration steps. In this study, two strategies for the immobilization of efficient tools for this purpose, thiol-modified (C3-SH) aptamers, on OSTE polymer surfaces were developed and compared. The first approach relies on a direct UV-initiated click chemistry reaction to graft thiol-terminated aptamers on ene-terminated OSTE surfaces. The second strategy consists of the immobilization of thiol-terminated aptamers onto OSTE substrates covered by gold nanoparticles. The presence of an intermediate gold nanoparticle layer on OSTE has shown great interest in the efficient immobilization of aptamers, preserving their interaction with the target, and preventing non-specific adsorption. With this second innovative strategy, we proved, for the first time the concept of creating multiple functional zones for sample treatment in an open OSTE-microchannel thanks to the immobilization of aptamers in consecutive areas by the simple droplet deposition methodology. This methodological development allows further consideration of OSTE material for lab-on-a-chip designs, integrating multiple zones for sample pretreatment, based on molecular recognition by ligands, such as aptamers, in a specific zone of the microchannel and is adaptable to a large range of analytical applications for LOAC industrialization. View Full-Text
Label-free graphene oxide–based SPR genosensor for the quantification of microRNA21
Laboratoire Synthèse Electrochimie Imagerie et Systèmes Analytiques - Michael López Mujica, Yuanyuan Zhang, Féthi Bédioui, Fabiana Gutiérrez & Gustavo Rivas
Analytical and Bioanalytical Chemistry - 412 3539–3546 - - 2020
This work is focused on the development of a genosensor for microRNA-21 quantification using surface plasmon resonance (SPR) to transduce the hybridization event. The biosensing platform was built by self-assembling two bilayers of poly(diallyldimethylammonium chloride) (PDDA) and graphene oxide (GO) at a gold surface modified with 3-mercaptopropane sulfonate (MPS), followed by the covalent attachment of the DNA probe. GO was used in two directions, to allow the anchoring of the probe DNA and to increase the sensitivity of the biosensing event due to its field enhancer effect. The new bioanalytical platform represents an interesting alternative for the label-free biosensing of microRNA-21, with a linear range between 1.0 fM and 10 nM, a sensitivity of 5.1 ± 0.1 moM−1 and a detection limit of 0.3fM. The proposed sensing strategy was successfully used for the quantification of microRNA-21 in enriched urine samples.

A maltol-containing Ruthenium Polypyridyl Complex as a Potential Anticancer Agent
Laboratoire Synthèse Electrochimie Imagerie et Systèmes Analytiques - Anna Notaro, Angelo Frei, Riccardo Rubbiani, Marta Jakubaszek, Uttara Basu, Severin Koch, Cristina Mari, Mazzarine Dotou, Olivier Blacque, Jérémie GouyonJérémie Gouyon Chimie ParisTech, PSL University, CNRS, Institute of Chemistry for Life and Health Sci
J. Med. Chem - 63(10) 5568–5584 - - 2020
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-sq was then scrutinized in vitro and in vivo, and the results highlight the promising potential of this complex as a chemotherapeutic agent against cancer.

Ruthenium(II) Complex Containing a Redox-Active Semiquinonate Ligand as a Potential Chemotherapeutic Agent: From Synthesis to In Vivo Studies
Laboratoire Synthèse Electrochimie Imagerie et Systèmes Analytiques - Dr. Anna Notaro Marta Jakubaszek Severin Koch Dr. Riccardo Rubbiani Dr. Orsolya Dömötör Dr. Éva A. Enyedy Mazzarine Dotou Dr. Fethi Bedioui
J. Med. Chem - 26 22 - - 2020
Cancer is one of the main causes of death worldwide. Chemotherapy, despite its severe side effects, is to date one of the leading strategies against cancer. Metal‐based drugs present several potential advantages when compared to organic compounds and they have gained trust from the scientific community after the approval on the market of the drug cisplatin. Recently, we reported the ruthenium complex ([Ru(DIP)2(sq)](PF6) (where DIP is 4,7‐diphenyl‐1,10‐phenantroline and sq is semiquinonate) with a remarkable potential as chemotherapeutic agent against cancer, both in vitro and in vivo. In this work, we analyse a structurally similar compound, namely [Ru(DIP)2(mal)](PF6), carrying the flavour‐enhancing agent approved by the FDA, maltol (mal). To possess an FDA approved ligand is crucial for a complex, whose mechanism of action might include ligand exchange. Herein, we describe the synthesis and characterisation of [Ru(DIP)2(mal)](PF6), its stability in solutions and under conditions that resemble the physiological ones, and its in‐depth biological investigation. Cytotoxicity tests on different cell lines in 2D model and on HeLa MultiCellular Tumour Spheroids (MCTS) demonstrated that our compound has higher activity than cisplatin, inspiring further tests. [Ru(DIP)2(mal)](PF6) was efficiently internalised by HeLa cells through a passive transport mechanism and severely affected the mitochondrial metabolism.

Increasing the Cytotoxicity of Ru(II) Polypyridyl Complexes by Tuning the Electronic Structure of Dioxo Ligands
Laboratoire Synthèse Electrochimie Imagerie et Systèmes Analytiques - Anna Notaro, Marta Jakubaszek, Nils Rotthowe, Federica Maschietto, Robin Vinck, Patrick S. Felder, Bruno Goud, Mickaël Tharaud, Ilaria Ciofini, Fethi Bedioui, Rainer F. Winter, and Gilles Gasser
J. Am. Chem. Soc. - 142(13) 6066–6084 - - 2020
Due to the great potential expressed by an anticancer drug candidate previously reported by our group, namely, Ru-sq ([Ru(DIP)2(sq)](PF6) (DIP, 4,7-diphenyl-1,10-phenanthroline; sq, semiquinonate ligand), we describe in this work a structure–activity relationship (SAR) study that involves a broader range of derivatives resulting from the coordination of different catecholate-type dioxo ligands to the same Ru(DIP)2 core. In more detail, we chose catechols carrying either an electron-donating group (EDG) or an electron-withdrawing group (EWG) and investigated the physicochemical and biological properties of their complexes. Several pieces of experimental evidences demonstrated that the coordination of catechols bearing EDGs led to deep-red positively charged complexes 1–4 in which the preferred oxidation state of the dioxo ligand is the uninegatively charged semiquinonate. Complexes 5 and 6, on the other hand, are blue/violet neutral complexes, which carry an EWG-substituted dinegatively charged catecholate ligand. The biological investigation of complexes 1–6 led to the conclusion that the difference in their physicochemical properties has a strong impact on their biological activity. Thus, complexes 1–4 expressed much higher cytotoxicities than complexes 5 and 6. Complex 1 constitutes the most promising compound in the series and was selected for a more in depth biological investigation. Apart from its remarkably high cytotoxicity (IC50 = 0.07–0.7 μM in different cancerous cell lines), complex 1 was taken up by HeLa cells very efficiently by a passive transportation mechanism. Moreover, its moderate accumulation in several cellular compartments (i.e., nucleus, lysosomes, mitochondria, and cytoplasm) is extremely advantageous in the search for a potential drug with multiple modes of action. Further DNA metalation and metabolic studies pointed to the direct interaction of complex 1 with DNA and to the severe impairment of the mitochondrial function. Multiple targets, together with its outstanding cytotoxicity, make complex 1 a valuable candidate in the field of chemotherapy research. It is noteworthy that a preliminary biodistribution study on healthy mice demonstrated the suitability of complex 1 for further in vivo studies.


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