Publications by authors named "Yves C Guillaume"

Poly(butyl methacrylate-co-ethylene dimethacrylate) monolith was in situ prepared in a liquid chromatography capillary column with a 75 μm internal diameter. This monolith offered high permeability (5.3 ± 10 m) and good peak capacity (140 for a 15 cm column length at 300 nl/min with a 20 min gradient time).

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Humic acid was the main compound in soil and reduced the availability of some organic compounds in soils. In this work, humic acid was immobilized for the first time on a homemade neutravidin poly(glycidyl methacrylate-co-ethylene dimethacrylate) capillary column with a 20 μm i.d.

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Heparan sulfate proteoglycan (HSPG) expressed on immune cell surface participate in antitumor T-cell responses generated in the acidic lymph node (LN) microenvironment. In this work, HSPG was immobilized for the first time on a HPLC chromolith support for studying the effect of extra cellular acidosis in LNs on the binding to HSPG of two peptide vaccines (universal cancer peptide UCP2 and UCP4). This home-made HSPG column enabling to work at high flow-rates, was resistance to change in pH, had a long - life time, an excellent repeatability and negligible non-specific binding sites.

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In this paper, each of the two following proteins, the angiotensin-converting enzyme 2 (ACE2) and the Main protease (Main pro) of the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) were grafted for the first time on homemade neutravidin poly(GMA-co-EDMA) capillary columns for the research of their ligands. The effect of the column diameter on the quantity of immobilized biotinylated protein was studied. For a capillary length of 40 mm, when its internal diameter varied from 75 to 25 μm, the grafted quantity of ACE2 decreased by 85% (from 1.

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A novel acetylcholinesterase Nano liquid chromatography capillary column (75 μm i.d. × 50 mm length) was developed for the fast screening of acetylcholinesterase inhibitors and the evaluation of their molecular recognition mechanism.

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For the design of novel potent molecules against therapeutic protein targets produced in a low quantity or that are very expensive, the development of miniaturized analytical techniques is of crucial importance. One challenging target is the receptor binding domain (RBD) of the SARS-CoV-2-spike protein (S), which mediates the binding of the virus to host cells. In the present study, the RBD protein was thus immobilized on polymethacrylate monoliths prepared in a miniaturized capillary column (25 μm internal diameter; 70 mm length) by polymerization, which could offer low backpressure in Nano LC at 30 nL min.

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The interactions of heparan sulfate proteoglycans (HSPGs) present on the cell surface with target proteins lead to cell signaling and they are considered as viral receptors. The analysis of the recognition mechanism between HSPG and its potential ligands and high-throughput screening in drug discovery thus remain important challenges. Glycidyl methacrylate-based monoliths were thus prepared in situ in miniaturized capillary columns (internal diameter 75 μm) and HSPG was grafted onto them by the use of the Schiff base method.

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A simple and rapid Nano LC method has been developed for the screening of arginase inhibitors. The method is based on the immobilization of biotinylated arginase on a neutravidin functionalized nano HPLC capillary column. The arginase immobilization step performed by frontal analysis is very fast and only takes a few minutes.

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TRAIL is a member of the tumor necrosis factor family of cytokines, which induces apoptosis of cancer cells, thanks to its binding to its cognate receptors DR5 and DR4. We have recently demonstrated that nanovectorization of TRAIL with single-walled carbon nanotubes enhanced TRAIL affinity to DR5. In this paper, 1-pyrenebutyric acid N-hydroxysuccinimide ester functionalized boron nitride nanotubes (BNNTs) were used to anchor the TRAIL protein.

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In this paper, a novel and very simple homogeneous coating of a monolithic silica HPLC support using pristine boron nitride nanotubes (BNNTs) was d0.escribed. The chromatographic support was coated with BNNTs in a non covalent way to preserve the nanotube structure.

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TRAIL is a member of the TNF family of cytokines which induces apoptosis of cancer cells via its binding to its cognate receptors, DR5 a high affinity site and DR4 a site of low affinity. Our working group has recently demonstrated that nanovectorization of TRAIL with single wall carbon nanotubes (abbreviated NPT) enhanced TRAIL affinity to the high affinity site DR5 and increased pro apoptotic potential in different human tumor cell lines. In this paper, the DR4 low affinity site was immobilized on a chromatographic support and the effect of temperature on a wide temperature range 1°C-50°C was studied to calculate the thermodynamic parameters of the binding of TRAIL and NPT to DR4 and DR5 receptors.

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Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces apoptosis of cancer cells when bound to its cognate receptors, TRAIL-R1 and TRAIL-R2 (DR4 and DR5), without being toxic to healthy cells. Nanovectorized TRAIL (abbreviated as NPT) is 10 to 20 times more efficient than one of the most potent soluble TRAIL used in preclinical studies (His-TRAIL). To determine whether differences in affinity may account for NPT superiority, a thermodynamic study was undertaken to evaluate NPT versus TRAIL binding affinity to DR5.

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A carbon nanotube (CNT) stationary phase was used for the first time to study the β-cyclodextrin (β-CD) solute complexation mechanism using high performance liquid chromatography (HPLC). For this, the β-CD was added at various concentrations in the mobile phase and the effect of column temperature was studied on both the retention of a series of aniline and benzoic acid derivatives with the CNT stationary phase and their complexation mechanism with β-CD. A decrease in the solute retention factor was observed for all the studied molecules without change in the retention order.

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In a previous paper Guillaume's group demonstrated that magnesium (Mg(2+) concentration range 0.00-2.60 mm) increased the passive diffusion of statins and thus played a role in their potential toxicity.

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The tetramer destabilization of transthyretin into monomers and its fibrillation are phenomena leading to amyloid deposition. Heparan sulfate proteoglycan (HSPG) has been found in all amyloid deposits. A chromatographic approach was developed to compare binding parameters between wild-type transthyretin (wtTTR) and an amyloidogenic transthyretin (sTTR).

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Patients suffering of Alzheimer's disease (AD) are characterized by a low transthyretin (TTR) level in the brain. The effect of pH and TTR concentration in the medium on the β-amyloid protein (Aβ)/heparan sulfate proteoglycan (HSPG) association mechanism were studied using a biochromatographic approach. For this purpose, HSPG was immobilized via amino groups onto the amino propyl silica pre-packed column, activated with glutaraldehyde, by using the Schiff base method.

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A new carbon nanotube porous silica poroshell stationary phase was developed. The chromatographic support was coated with ultrashort single-wall carbon nanotubes (SWCNTs) in a noncovalent way. It was demonstrated that the porous amino silica surface of the 300 NH2 poroshell column stabilized with 1-methyl-2-pyrrolidinone efficiently and stably adsorbed SWCNTs onto the chromatographic support.

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This work deals with the development of a carbon nanotube (CNT) monolithic column coated with a pyrenyl derivative as chiral selector. For this, a solution of pyrenyl neomycine A was pumping through a monolithic CNT column previously developed by our group. This coating was stable against the desorption for months when aqueous mobile phases were used.

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A biochromatographic system was used to study the direct effect of carbon nanoparticles (CNPs) on the acetylcholinesterase (AChE) activity. The AChE enzyme was covalently immobilized on a monolithic CIM-disk via its NH2 residues. Our results showed an increase in the AChE activity in presence of CNPs.

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In this paper, an effective and simple method was used for the immobilization of single wall carbon nanotubes (SWCNTs) on a monolithic HPLC material containing 2 μm macropore sizes and 13 nm mesopore sizes. The chromatographic support was coated with ultra short SWCNTs in a noncovalent way to preserve the sp(2) nanotube structure and thus their physico-chemical properties. It was demonstrated that the amino-surface of the monolith stabilized with 1-methyl-2-pyrrolidinone efficiently and stably adsorbed SWCNTs onto the chromatographic support.

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In this paper, a new and effective method was described for attaching gold nanoparticles (Au-NPs) on to the surface of thiol-terminated Boron Nitride Nanotubes (BNNT) functionalized with quinuclidine-3-thiol, acting as a bridging agent. The quinuclidine-3-thiol was first grafted onto the surface of the BNNTs via strong interactions between the electron pair from the nitrogen atom of the quinuclidine structure and the electronic gap from the boron atom of the BNNT. The bare surface of Au-NPs facilitates to attach on the thiol group of the thiol-terminated BNNTs.

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Multiwalled carbon nanotubes have been entrapped in a porous monolithic chromatographic support. This support was used for the covalent immobilization of the arginase enzyme a novel target in hypertension. The effect of the nanotube (NT) amount into the monolith was analyzed.

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The retention mechanism of a series of peptides on a single-wall carbon nanotube (SWCNT) stationary phase inside an HPLC column was investigated over a wide range of mobile phase compositions. While the similar size C18 column exhibited an efficiency of 11.5 μm, the SWCNT column increased the efficiency, i.

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This work was dedicated to the development of a new micro immobilized enzyme reactor (IMER) by using an in situ procedure. Arginase was covalently immobilized on an ethylenediamine (EDA) monolithic convective interaction media (CIM) disk (12mm × 3mm i.d.

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Arginase is an enzyme which plays a role in pathophysiology such as hypertension. Here we demonstrated for the first time the direct implication of pressure and OH° radical formation on the arginase activity via a novel analytical procedure. Pressure increased arginase activity in the range 12-52bars.

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