Publications by authors named "Granjon T"

Nanocarriers have found their interests in many fields including drug delivery and labeling of cells with the aim to target and eradicate tumor cells. One of the approaches to specifically address nanocarriers, such as liposomes, to their target is to attach antibodies of interest to their surface. To date, the development of immunoliposomes has been widely explored but has mainly involved chemical and unspecific reactions that could impair antibody stability, integrity, and orientation, thus reducing optimized immunoliposomes generation.

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The history of joint replacement can be framed as a battle to reduce wear. Pyrocarbon has been shown to be a low wear material, but can low wear against an ultra high molecular weight polyethylene (UHMWPE) counterface be achieved? To investigate this research question, a 50-station, clinically validated wear screening machine was used. Half the stations tested UHMWPE pins against pyrocarbon discs, and half the stations tested UHMWPE pins against cobalt chromium (CoCr) discs.

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To ensure selective targeting based on membrane fluidity and physico-chemical compatibility between the biological membrane of the target cell and the lipid membrane of the liposomes carriers. Lipid-based carriers as liposomes with varying membrane fluidities were designed for delivering vincristine, an anti-tumor compound derived from Madagascar's periwinkle. Liposomes, loaded with vincristine, were tested on prostate, colon, and breast cancer cell lines alongside non-tumor controls.

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Nanomedicines engineered to deliver molecules with therapeutic potentials, overcoming drawbacks such as poor solubility, toxicity or a short half-life, are targeted towards their cellular destination either passively or through various elements of cell membranes. The differences in the physicochemical properties of the cell membrane between tumor and nontumor cells have been reported, but they are not systematically used for drug delivery purposes. Thus, in this study, a new approach based on a match between the liposome compositions, i.

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mRNA based infectious disease vaccines have opened the venue for development of novel nucleic acids-based therapeutics. For all mRNA therapeutics dedicated delivery systems are required, where different functionalities and targeting abilities need to be optimized for the respective applications. One option for advanced formulations with tailored properties are lipid-polymer hybrid nanoparticles with complex nanostructure, which allow to combine features of several already well described nucleic acid delivery systems.

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Two florescent xanthene-cyanamide lysosomal trackers emitting strongly at ∼525 nm were prepared from fluorescein and rhodol methyl esters in microwave-assisted reactions. Both forms named "off" (nonfluorescent lactam) and "on" (strongly fluorescent ring-opened amide) have been comprehensively characterized out by using a combination of NMR spectroscopy, X-ray analysis, fluorimetry and confocal microscopy. Known rhodamines bearing electron-withdrawing groups (EWGs) exhibit an equilibrium between non-fluorescent (off) and fluorescent (on) depending on the dielectric constant of the medium.

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The morphology of fibroblast-like synoviocytes (FLS) issued from the synovial fluid (SF) of patients suffering from osteoarthritis (OA), rheumatoid arthritis (RA), or from healthy subjects (H), as well as the ultrastructure and mechanical properties of the FLS-secreted extracellular vesicles (EV), were analyzed by confocal microscopy, transmission electron microscopy, atomic force microscopy, and tribological tests. EV released under healthy conditions were constituted of several lipid bilayers surrounding a viscous inner core. This "gel-in" vesicular structure ensured high mechanical resistance of single vesicles and good tribological properties of the lubricant.

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The quality of the lubricant between cartilaginous joint surfaces impacts the joint's mechanistic properties. In this study, we define the biochemical, ultrastructural, and tribological signatures of synovial fluids (SF) from patients with degenerative (osteoarthritis-OA) or inflammatory (rheumatoid arthritis-RA) joint pathologies in comparison with SF from healthy subjects. Phospholipid (PL) concentration in SF increased in pathological contexts, but the proportion PL relative to the overall lipids decreased.

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Article Synopsis
  • The biochemical process of bone mineralization via matrix vesicles relies on specific lipids, enzymes, and proteins, particularly annexins, which aid in forming the nucleational core of these vesicles.
  • In a study, AnxA6 was tested for its role in mineralization with and without type-I collagen while using different nucleators such as amorphous calcium phosphate and a phosphatidylserine-calcium phosphate complex.
  • Results showed that AnxA6 did not effectively propagate mineralization with liposomes in the presence of type-I collagen, suggesting its interaction might be more about forming a nucleation center rather than promoting mineral growth directly.
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Matrix vesicles (MVs) are 100-300 nm spherical structures released by mineralization competent cells to initiate formation of apatite, the mineral component in bones. Among proteins present in MVs, annexin A6 (AnxA6) is thought to be ubiquitously distributed in the MVs' lumen, on the surface of the internal and external leaflets of the membrane and also inserted in the lipid bilayer. To determine the molecular mechanism(s) that lead to the different locations of AnxA6, we hypothesized the occurrence of a pH drop during the mineralization.

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Novel nanomedicines have been engineered to deliver molecules with therapeutic potentials, overcoming drawbacks such as poor solubility, toxicity or short half-life. Lipid-based carriers such as liposomes represent one of the most advanced classes of drug delivery systems. A Monomethyl Auristatin E (MMAE) warhead was grafted on a lipid derivative and integrated in fusogenic liposomes, following the model of antibody drug conjugates.

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Background: Aryl phosphate esters (APEs) are widely used and commonly present in the environment. Health hazards associated with these compounds remain largely unknown and the effects of diphenyl phosphate (DPhP), one of their most frequent derivatives, are poorly characterized.

Objective: Our aim was to investigate whether DPhP per se may represent a more relevant marker of exposure to APEs than direct assessment of their concentration and determine its potential deleterious biological effects in chronically exposed mice.

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Lipid-based carriers such as liposomes represent one of the most advanced classes of drug delivery systems. Their clinical success relies on their composition, similar to that of the cell membrane. Their cellular specificity often relies on a ligand-receptor interaction.

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Article Synopsis
  • Annexin A6 (AnxA6) is a key protein found in matrix vesicles which are crucial for mineralization in cartilage and bone.
  • The study identifies three distinct localizations of AnxA6 within the MV membrane: bound to the inner leaflet with calcium, on the outer leaflet, and embedded within the bilayer alongside cholesterol.
  • AnxA6 interactions with the membrane are influenced by calcium and lipid composition, as shown by biochemical and thermodynamic analyses, which indicate that cholesterol enhances the recruitment of AnxA6.
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Background: Considering the importance of cellular mechanics in the birth and evolution of cancer towards increasingly aggressive stages, we compared nano-mechanical properties of non-tumoral (WPMY-1) and highly aggressive metastatic (PC-3) prostate cell lines both on cell aggregates, single cells, and membrane lipids.

Methods: Cell aggregate rheological properties were analyzed during dynamic compression stress performed on a homemade rheometer. Single cell visco-elasticity measurements were performed by Atomic Force Microscopy using a cantilever with round tip on surface-attached cells.

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Background: Mitochondrial creatine kinase (mtCK) is highly abundant in mitochondria; its quantity is equimolecular to the Adenylic Nucleotide Translocator and represents 1% of the mitochondrial proteins. It is a multitask protein localized in the mitochondria intermembrane space where it binds to the specific cardiolipin (CL) phospholipid. If mtCK was initially thought to be exclusively implicated in energy transfer between mitochondria and cytosol through a mechanism referred to as the phosphocreatine shuttle, several recent studies suggested an additional role in maintaining mitochondria membrane structure.

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Nucleoside diphosphate kinases (NDPKs) are crucial elements in a wide array of cellular physiological or pathophysiological processes such as apoptosis, proliferation, or metastasis formation. Among the NDPK isoenzymes, NDPK-B, a cytoplasmic protein, was reported to be associated with several biological membranes such as plasma or endoplasmic reticulum membranes. Using several membrane models (liposomes, lipid monolayers, and supported lipid bilayers) associated with biophysical approaches, we show that lipid membrane binding occurs in a two-step process: first, initiation by a strong electrostatic adsorption process and followed by shallow penetration of the protein within the membrane.

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4-Hydroxy-2-nonenal (4-HNE) is a reactive aldehyde and a lipid peroxidation product formed in biological tissues under physiological and pathological conditions. Its concentration increases with oxidative stress and induces deleterious modifications of proteins and membranes. Mitochondrial and cytosolic isoforms of creatine kinase were previously shown to be affected by 4-HNE.

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Conventional liposomes have a short life-time in blood, unless they are protected by a polymer envelope, most often polyethylene glycol. However, these stabilizing polymers frequently interfere with cellular uptake, impede liposome-membrane fusion and inhibit escape of liposome content from endosomes. To overcome such drawbacks, polymer-based systems as carriers for liposomes are currently developed.

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NDPK-A, NDPK-B and NDPK-D are three enzymes which belong to the NDPK group I isoforms and are not only involved in metabolism process but also in transcriptional regulation, DNA cleavage, histidine protein kinase activity and metastasis development. Those enzymes were reported to bind to membranes either in mitochondria where NDPK-D influences cardiolipin lateral organization and is thought to be involved in apoptotic pathway or in cytosol where NDPK-A and NDPK-B membrane association was shown to influence several cellular processes like endocytosis, cellular adhesion, ion transport, etc. However, despite numerous studies, the role of NDPK-membrane association and the molecular details of the binding process are still elusive.

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Caspase-8 is involved in death receptor-mediated apoptosis in type II cells, the proapoptotic programme of which is triggered by truncated Bid. Indeed, caspase-8 and Bid are the known intermediates of this signalling pathway. Cardiolipin has been shown to provide an anchor and an essential activating platform for caspase-8 at the mitochondrial membrane surface.

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Nucleoside Diphosphate Kinases (NDPKs) have long been considered merely as housekeeping enzymes. The discovery of the NME1 gene, an anti-metastatic gene coding for NDPK-A, led the scientific community to re-evaluate their role in the cell. It is now well established that the NDPK family is more complex than what was first thought, and despite the increasing amount of evidence suggesting the multifunctional role of nm23/NDPKs, the specific functions of each family member are still elusive.

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It has been recently shown that mitochondrial creatine kinase (mtCK) organizes mitochondrial model membrane by modulating the state and fluidity of lipids and by promoting the formation of protein-cardiolipin clusters. This report shows, using Brewster angle microscopy, that such clustering is largely dependent on the acyl chain composition of phospholipids. Indeed, mtCK-cardiolipin domains were observed not only with unsaturated cardiolipins, but also with the cardiolipin precursor phosphatidylglycerol.

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Background: Oxaloacetate decarboxylase (OAD) is a member of the Na(+) transport decarboxylase enzyme family found exclusively in anaerobic bacteria. OAD of Vibrio cholerae catalyses a key step in citrate fermentation, converting the chemical energy of the decarboxylation reaction into an electrochemical gradient of Na(+) ions across the membrane, which drives endergonic membrane reactions such as ATP synthesis, transport and motility. OAD is a membrane-bound enzyme composed of alpha, beta and gamma subunits.

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Mitochondrial creatine kinase (mtCK) binding to the mitochondrial inner membrane largely determines its biological functions in cellular energy homeostasis, mitochondrial physiology, and dynamics. The membrane binding mechanism is, however, not completely understood. Recent data suggest that a hydrophobic component is involved in mtCK binding to cardiolipin at the outer face of the inner mitochondrial membrane, in addition to the well known electrostatically driven process.

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