Pascale Chevallier - Academia.edu (original) (raw)

Papers by Pascale Chevallier

Materials Today Communications

Journal of Biomedical Materials Research Part A, 2021

Intraosseous transcutaneous amputation prosthesis is a new approach in orthopedic implants that o... more Intraosseous transcutaneous amputation prosthesis is a new approach in orthopedic implants that overcomes socket prosthesis problems. Its long‐term performance requires a tight skin‐implant seal to prevent infections. In this study, fibronectin (Fn), a widely used adhesion protein, was adsorbed or grafted onto titanium alloy. Fn grafting was performed using two different linking arms, dopamine/glutaric anhydride or phosphonate. The characterization of Fn‐modified surfaces showed that Fn grating via phosphonate has led to the highest amount of Fn cell‐binding site (RGD, arginine, glycine, and aspartate) available on the surface. Interestingly, cell culture studies revealed a strong correlation between the amount of available RGD ligands and cellular behavior, since enhanced proliferation and spreading of fibroblasts were noticed on Fn‐grafted surfaces via phosphonate. In addition, an original in vitro mechanical test, inspired from the real situation, to better predict clinical outco...

Frontiers in Bioengineering and Biotechnology, 2022

Natural polymer-based films, due to their favorable biological and mechanical properties, have de... more Natural polymer-based films, due to their favorable biological and mechanical properties, have demonstrated great potential as coatings for biomedical applications. Among them, chitosan films have been widely studied both as coating materials and as controlled drug release systems. Crosslinkers are often used to tune chitosan’s crosslinking degree and thus to control the drug release kinetics. For this purpose, quercetin, a plant-derived natural polyphenol, has gained attention as a crosslinker, mainly for its intrinsic anti-inflammatory, antioxidant, and antibacterial features. In this study, chitosan films crosslinked with three different concentrations of quercetin (10, 20, and 30% w/w) have been used as controlled release systems for the delivery of the antibacterial drug trimethoprim (TMP, 10% w/w). Physicochemical and antimicrobial properties were investigated. Surface wettability and composition of the films were assessed by contact angle measurements, X-ray photoelectron spe...

Journal of Power Sources, 2019

In this work, we deposited a nanometric layer of platinum (40 nm thick) on a standard propylene/p... more In this work, we deposited a nanometric layer of platinum (40 nm thick) on a standard propylene/polypropylene Celgard separator 3501 by plasma sputtering, and studied the effect of this thin layer when in contact with a lithium metal anode in a Li-S battery. The platinum-coated Celgard slowed down the shuttle effect at low current density (C/10) compared to standard Celgard and led to an increase in capacity retention at higher current density (C/2). In addition, the polarization was reduced with a platinum separator in a Li-Li symmetric cell after 500 h.

Arabian Journal of Chemistry, 2016

The use of semiconductor oxides, such as chemical or biological sensors, requires their functiona... more The use of semiconductor oxides, such as chemical or biological sensors, requires their functionalization with appropriate molecules displaying specific interaction with the substance to be detected. Generally, the support materials used are TiO 2 or SiO 2. In the present work, zinc oxide nanoparticles (ZnO NPs), known for its reactivity and high specific area, were used. The synthesis of nanoscale ZnO was advantageously performed by precipitation at low temperature (60°C). To our knowledge, it was the first time that this material was synthesized at such a low temperature, therefore lowering production cost. Moreover, the surface functionalization of ZnO was performed with N-(trimethoxysilylpropyl) ethylenediamine triacetic acid (TMSEDTA) in ethanol. This allowed shortening the functionalization reaction duration as compared to previously published literature * Corresponding author. Peer review under responsibility of King Saud University.

Biopolymer Membranes and Films, 2020

Abstract Coatings with a polymeric membrane layer represent a recognized strategy to modulate int... more Abstract Coatings with a polymeric membrane layer represent a recognized strategy to modulate interactions between material surfaces and blood environments. The coating should be able to limit platelet adhesion and delay clot formation to the implant surface. Polysaccharide coatings have been used to prevent nonspecific adsorption of blood and enhance the hemocompatible properties of metallic devices. Different natural polymers have been used to coat metal surfaces, such as chitosan, alginate, hyaluronic acid, collagen, heparin, and other representative organic compounds. The introduction of sulfate groups on the chitosan chain has attracted much attention due to its potential to mimic the effects promoted by heparin. Sulfated chitosan membranes have been evaluated to reduce protein adsorption, decrease thrombogenic properties, and limit clot formation. In this chapter, we focus on two types of sulfated chitosan membranes, and it is established that biological responses depend on the sulfated chemical modification position: amino or hydroxyl groups. The coating of metal surfaces (stainless steel and titanium alloys) using sulfated polysaccharides is also described. These sulfated surfaces limit platelet activation and the clot formation process, confirming its high biological performance for blood-contact devices.

Frontiers in Cellular and Infection Microbiology, 2021

IntroductionThe use of spinal implants for the treatment of back disorders is largely affected by... more IntroductionThe use of spinal implants for the treatment of back disorders is largely affected by the insurgence of infections at the implantation site. Antibacterial coatings have been proposed as a viable solution to limit such infections. However, despite being effective at short-term, conventional coatings lack the ability to prevent infections at medium and long-term. Hydrogel-based drug delivery systems may represent a solution controlling the release of the loaded antibacterial agents while improving cell integration. Agarose, in particular, is a biocompatible natural polysaccharide known to improve cell growth and already used in drug delivery system formulations. In this study, an agarose hydrogel-based coating has been developed for the controlled release of gentamicin (GS).MethodsSand blasted Ti6Al4V discs were grafted with dopamine (DOPA) solution. After, GS loaded agarose hydrogels have been produced and additioned with tannic acid (TA) and calcium chloride (CaCl2) as c...

Polymer-Plastics Technology and Materials, 2021

ABSTRACT In biomedical application, the fabrication of biodegradable scaffolds using 3D printing ... more ABSTRACT In biomedical application, the fabrication of biodegradable scaffolds using 3D printing technology has vastly increased to accommodate the complex structure of substitutes. In this study, PLLA and PDLA were hot-melt extruded for the 3D printing of PLLA/PDLA scaffolds. The incorporation of PDLA into the PLLA has enhanced the hydrophobicity and mechanical properties of the scaffolds. The degraded PLLA/PDLA scaffolds were observed to retain its chemical functionalities. Less crack formation, less acidity of the degraded solution, higher percentages of remaining weight, greater average molecular weight, and higher crystallinity percentages were recorded on the higher PDLA composition after the degradation analysis. Graphical Abstract

Biomass Conversion and Biorefinery, 2021

With increasing demand for biobased materials, major importance was given to the extraction and a... more With increasing demand for biobased materials, major importance was given to the extraction and application of polysaccharides issued from renewable biomasses like algae. In this work, we investigate the feasibility of elaborating an active ulvan-based biomembrane prepared from stranded Ulva sp. biomass. Variations of extraction parameters showed that the optimal yield (13.8% w/w) was obtained using methanol under Soxhlet extraction for the defatting step and 5% (w/v) of ammonium oxalate as chelating reagent. The molecular weight (MW) was determined by gel permeation chromatography (GPC), which showed variability of MW from 201 to 1841 kDa depending on the extraction procedure. The monosaccharide composition of the obtained high MW ulvan showed the presence of rhamnose (17.61 ± 0.5%), xylose (9.22 ± 0.56%), and glucuronic acid (24.86 ± 1.29%). Purity and quality of ulvan were also assessed by FTIR and TGA analyses. The high MW ulvan fraction was thereafter used for the synthesis of ...

Corrosion, 2018

Localized corrosion constitutes a major concern in medical devices made of stainless steel. The c... more Localized corrosion constitutes a major concern in medical devices made of stainless steel. The conventional approach to circumvent such a problem is to convert the surface polycrystalline microstructure of the native oxide layer to an amorphous oxide layer, a few micrometers thick. This process cannot, however, be used for devices such as stents that undergo plastic deformation during their implantation, especially those used in vascular surgery for the treatment of cardiac, neurological, and peripheral vessels. This work explores the feasibility of producing a nano-thick plastic-deformation resistant amorphous oxide layer by plasma-based surface modifications. By varying the plasma process parameters, oxide layers with different features were produced and their properties were investigated before and after clinically-relevant plastic deformation. These properties and the related corrosion mechanisms were mainly evaluated using the electrochemical methods of open-circuit potential,...

Colloids and Surfaces B: Biointerfaces, 2020

Atmospheric pressure cold plasma versus classical chemical treatments for carboxyl functionalizat... more Atmospheric pressure cold plasma versus classical chemical treatments for carboxyl functionalization of PLA surfaces: A first step toward covalent grafting of bioactive molecules,

Cellulose, 2020

Bacterial cellulose (BC) membrane can be architected to covalently immobilize biomolecules, gener... more Bacterial cellulose (BC) membrane can be architected to covalently immobilize biomolecules, generating materials with new functionality. The processes of purification (via alkaline treatment) and chemical modification (via NaIO 4) to the wet BC membrane is the innovation of this work. This wet oxidized BC (OxBC) membrane could act as a support matrix for covalent immobilization of enzymes. BC produced over 5 days of static fermentation, followed by purification with K 2 CO 3 (BC-5d-K 2 CO 3) was selected for our study due to high porosity and surface area, which are properties that favor its chemical modification. This wet BC membrane proven suitable for NaIO 4 oxidation. Time and temperature conditions were evaluated in the oxidation reaction, with oxidation BC (OxBC) performed at 1% (w/v) NaIO 4 for 6 h at 55°C under most advantageous conditions, as it provided 50% oxidation degree and preserved its morphological structure. BC and OxBC were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, Scanning electron microscopy, mechanical test, and thermal analysis. The oxidation reaction decreased BC crystallinity, tensile strength, and thermal stability and compacted the cellulose layers. BC and OxBC showed non-cytotoxicity. Fourier transform infrared confirmed that OxBC can covalently immobilize papain and that after immobilization the enzyme showed a recovered enzymatic activity of 93.1%. In addition, the oxidized membrane presented greater amount of immobilized papain in its study than BC, proving to be a more efficient support for enzymatic immobilization.

RSC Advances, 2019

Optimization of the oxide layer of L605 alloys based on the desired properties for stent applicat... more Optimization of the oxide layer of L605 alloys based on the desired properties for stent applications: deformation, corrosion, plasma-amination and biocompatibility.

Plasma Processes and Polymers, 2018

Stents are cardiovascular devices used to treat atherosclerosis, and are deployed into narrowed a... more Stents are cardiovascular devices used to treat atherosclerosis, and are deployed into narrowed arteries and implanted by expansion to reopen the biological lumen. Nevertheless, complications after implantation are still observed in 10-14% of the implantations. Therefore, functionalizing these devices with active molecules to improve the interfacial effects with the surrounding tissue strongly impacts their success. A plasmabased procedure to directly graft biomolecules to the surface of cobalt chromium alloys, without any polymeric coating, has been recently reported. Assuring the stability of the coating during plastic deformation generated during the implantation whilst avoiding the corrosion of the surface is crucial. This study explores different surface treatments to be used as a pre-treatment for this novel procedure. The effects of (i) electropolishing, (ii) thermal treatments, and (iii) the plasma immersion ion implantation of oxygen on the chemical composition, roughness, wettability and efficiency during the plasmaamination procedure whilst avoiding cracks after deformation, thus maintaining corrosion resistant behaviour, were investigated by XPS, AFM, ToF-SIMS imaging and depth profile, and WCA. Furthermore, the hemocompatibility of the surface and cell viability assays were also performed. Results showed that all of the treatments created a different surface chemical composition: EP mainly of chromium oxide, PIII with a layer of cobalt oxide and TT with a mixture of oxides, as observed by XPS and ToF-SIMS. Moreover, EP was the process that generated a surface with the highest efficiency to amination and the most corrosion resistance among the treatments, and it appeared as the most suitable pre-treatment for stent functionalization.

ACS Biomaterials Science & Engineering, 2017

Within the native microenvironment, extracellular matrix (ECM) components are thought to display ... more Within the native microenvironment, extracellular matrix (ECM) components are thought to display a complex and heterogeneous distribution, spanning several length scales. Herein, the objective is to mimic, in vitro, the hierarchical organization of proteins and growth factors as well as their crosstalk. Photolithography technique was used to adjacently pattern geometrically-defined regions of RGD and BMP-2 mimetic peptides onto glass substrates. These ECM-derived ligands are known to jointly regulate mesenchymal stem cells (MSCs) osteogenic differentiation. By manipulating the spatial distribution of dually grafted peptides, the extent of human MSCs osteogenic differentiation was significantly affected, depending on the shape of peptide micropatterns. Our data highlight the existence of a strong interplay between geometric cues and biochemical signals. Such in vitro systems provide a valuable tool to investigate mechanisms by which multiple ECM cues overlap to regulate stem cell fate, thereby contributing to the design of bioinspired biomaterials for bone tissue engineering applications.

$Research paper thumbnail of Characterization of Amorphous Oxide Nano-Thick Layers on 316L Stainless Steel by Electron Channeling Contrast Imaging and Electron Backscatter Diffraction$

Microscopy and Microanalysis, 2016

Characterization of the topmost surface of biomaterials is crucial to understanding their propert... more Characterization of the topmost surface of biomaterials is crucial to understanding their properties and interactions with the local environment. In this study, the oxide layer microstructure of plasma-modified 316L stainless steel (SS316L) samples was analyzed by a combination of electron backscatter diffraction and electron channeling contrast imaging using low-energy incident electrons. Both techniques allowed clear identification of a nano-thick amorphous oxide layer, on top of the polycrystalline substrate, for the plasma-modified samples. A methodology was developed using Monte Carlo simulations combined with the experimental results to estimate thickness of the amorphous layer for different surface conditions. X-ray photoelectron spectroscopy depth profiles were used to validate these estimations.

Journal of Magnetism and Magnetic Materials, 2015

ABSTRACT Powders of magnetic iron oxide nanoparticles (Mg0.2Ca0.8Fe2O4) were prepared by a sol-ge... more ABSTRACT Powders of magnetic iron oxide nanoparticles (Mg0.2Ca0.8Fe2O4) were prepared by a sol-gel method using ethylene glycol and nitrates of Fe, Ca and Mg as starting materials. Those powders were heat treated at different temperatures (573, 673, 773 and 873 K). In order to evaluate the effect of the heat treatment temperature on the nanoferrites properties, X-ray diffraction (XRD), vibrating sample magnetometry (VSM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) techniques were used. It was found that the reaction products exhibit nanometric sizes and superparamagnetic behavior. It is also demonstrated that, as the heat treatment temperature increases, the particle size and the saturation magnetization of the nanoferrites are increased.

The Journal of Physical Chemistry B, 2001

A cylindrically configured plasma treatment system for Radio Frequency Glow discharges fed with a... more A cylindrically configured plasma treatment system for Radio Frequency Glow discharges fed with ammonia was used to modify the internal surface of ePTFE arterial prostheses to improve their biocompatibility. For a better understanding of the effects of this type of treatment on the surface, RF-plasmas were also performed on PTFE films. The surface chemical composition was then characterized by XPS. The initial analyses showed that 15% of the surface atoms were replaced by nitrogen (N/C ratio of 0.3), whereas the F/C ratio decreased from 2 to 0.7-0.5 which indicates that the treated surfaces presented different chemical species, such as amine, imine, amide, acid groups, and insaturations. As XPS analyses could not lead directly to the nature of the N-species grafted on the surface (the chemical shifts being not significantly different), chemical derivatization was thus performed. Vapor phase chemical derivatization was carried out on model polymers to evaluate the reactivity and the selectivity of each reagent toward each of the expected functional groups. The results indicate that benzaldehyde derivatives were good derivatizing reagents for amine groups, whereas bromine was the reagent of choice to quantify the insaturations. Using these methods, the amine and alkene concentrations on the surface were found to increase according to plasma treatment time rising from their initial value of 3% for a 50 s plasma treatment to 6% for a 250 s plasma treatment. AFM studies on oriented Teflon films also demonstrated that the occurrence of chain breaking increased with plasma treatment time. It therefore appears that determining the treatment parameters should require the best compromise between several effects such as nitrogen grafting, amine and alkene formation, and chain breaking.

Bioactive Materials, 2021

In this exploratory work, micrometric radiopaque W–Fe–Mn–C coatings were produced by magnetron sp... more In this exploratory work, micrometric radiopaque W–Fe–Mn–C coatings were produced by magnetron sputtering plasma deposition, for the first time, with the aim to make very thin Fe–Mn stents trackable by fluoroscopy. The power of Fe–13Mn-1.2C target was kept constant at 400 W while that of W target varied from 100 to 400 W producing three different coatings referred to as P100, P200, P400. The effect of the increased W power on coatings thickness, roughness, structure, corrosion behavior and radiopacity was investigated. The coatings showed a power-dependent thickness and W concentration, different roughness values while a similar and uniform columnar structure. An amorphous phase was detected for both P100 and P200 coatings while γ-Fe, bcc-W and W3C phases found for P400. Moreover, P200 and P400 showed a significantly higher corrosion rate (CR) compared to P100. The presence of W, W3C as well as the Fe amount variation determined two different micro-galvanic corrosion mechanisms significantly changing the CR of coatings, 0.26 ± 0.02, 59.68 ± 1.21 and 59.06 ± 1.16 μm/year for P100, P200 and P400, respectively. Sample P200 with its most uniform morphology, lowest roughness (RMS = 3.9 ± 0.4 nm) and good radiopacity (∼6%) appeared the most suitable radiopaque biodegradable coating investigated in this study.

Separation and Purification Technology, 2019

Ion-exchange membranes (IEM) used in electrodialysis (ED) possess an intrinsic resistance that co... more Ion-exchange membranes (IEM) used in electrodialysis (ED) possess an intrinsic resistance that contributes to the energy consumption of ED treatments. In this work, the performance of cation-coated filtration membranes (CCFM), which are more conductive and less expansive than conventional IEMs, was investigated for the first time on food applications. Four CCFMs (FF50-B3X, FF50-WPR00, FF30-S11 and FF60-S11) were tested for NaCl solution demineralization and two of them (FF50-B3X and FF30-S11) were further tested for whey demineralization in comparison with an AMX anionexchange membrane, commercially available and currently used in industrial stacks. During NaCl solution demineralization, no significant differences were observed between CCFMs and AMX membranes in terms of demineralization, global resistance and energy consumption. However, during whey demineralization, CCFMs were slightly less effective in terms of demineralization rate (15% less, FF30-S11 only) and energy consumption (both CCFMs): this was explained by the higher roughness and thickness of CCFMs. Furthermore, the overall resemblance in terms of electrochemical characteristics between CCFMs and AMX was in accordance with the results obtained for NaCl solution and whey demineralization. Considering the relatively low electrical energy needed by CCFMs in the overlimiting region, these membranes could also be of interest for ED treatments in overlimiting current conditions. Thus, CCFMs, which are low-cost membranes (40-60 €/m 2), could be used for ED at a larger scale.