References of "Maquet, Véronique"
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See detailBioresorbable and bioactive composite materials based on polylactide foams filled with and coated by Bioglass (R) particles for tissue engineering applications
Boccaccini, Aldo R.; Notingher, I.; Maquet, Véronique et al

in Journal of Materials Science: Materials in Medicine (2003), 14(5), 443-450

Poly(DL-lactide) (PDLLA) foams and bioactive glass (Bioglass®) particles were used to form bioresorbable and bioactive composite scaffolds for applications in bone tissue engineering. A thermally induced ... [more ▼]

Poly(DL-lactide) (PDLLA) foams and bioactive glass (Bioglass®) particles were used to form bioresorbable and bioactive composite scaffolds for applications in bone tissue engineering. A thermally induced phase separation process was applied to prepare highly porous PDLLA foams filled with 10wt% Bioglass® particles. Stable and homogeneous layers of Bioglass® particles on the surface of the PDLLA/Bioglass® composite foams as well as infiltration of Bioglass® particles throughout the porous network were achieved using a slurry-dipping technique. The quality of the bioactive glass coatings was reproducible in terms of thickness and microstructure. In vitro studies in simulated body fluid (SBF) were performed to study the formation of hydroxyapatite (HA) on the surface of the PDLLA/Bioglass® composites, as an indication of the bioactivity of the materials. Formation of the HA layer after immersion in SBF was confirmed by X-ray diffraction and Raman spectroscopy measurements. The rate of HA formation in Bioglass®-coated samples was higher than that observed in non-coated samples. SEM analysis showed that the HA layer thickness rapidly increased with increasing time in SBF in the Bioglass®-coated samples. The high bioactivity of the developed composites suggests that the materials are attractive for use as bioactive, resorbable scaffolds in bone tissue engineering. [less ▲]

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See detailImage analysis of the axonal ingrowth into poly(D,L-lactide) porous scaffolds in relation to the 3-D porous structure
Blacher, Silvia ULg; Maquet, Véronique; Luyckx, Françoise ULg et al

in Biomaterials (2003), 24(6), 1033-1040

Porous polymer scaffolds are promising materials for neural tissue engineering because they offer valuable three-dimensional (3D) supports for the in vitro and in vivo axonal growth and tissue expansion ... [more ▼]

Porous polymer scaffolds are promising materials for neural tissue engineering because they offer valuable three-dimensional (3D) supports for the in vitro and in vivo axonal growth and tissue expansion. At the time being, how the in vivo neuronal cell development depends on the scaffold 3-D architecture is unknown. Therefore, scanning electron micrographs of longitudinal sections of porous polylactide scaffolds and immunohistological sections of these scaffolds after implantation and neurofilament staining have been studied by image analysis. Pore orientation and axonal ingrowth have been investigated by spectral analysis on gray level SEM images. Binary image processing has been carried out and the binary images have been studied by spectral analysis in order to estimate the possible effect of the image noise on the real pattern. In addition to axonal orientation, density and length distribution of the regenerated axons into the polymer scaffold have been measured. Dependence of the axonal ingrowth on the 3D-polymer scaffold has been discussed on the basis of the collected data. (C) 2002 Elsevier Science Ltd. All rights reserved. [less ▲]

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See detailProcess for depositing strong adherend polymer coating onto an electrically conductive surface
Detrembleur, Christophe ULg; Lou, Xudong; Voccia, Samuel et al

Patent (2002)

Process for depositing by electrografting a strong adherent polymer coating onto an electrically conductive surface comprising an electrochemical grafting at the surface of an active monomer for forming a ... [more ▼]

Process for depositing by electrografting a strong adherent polymer coating onto an electrically conductive surface comprising an electrochemical grafting at the surface of an active monomer for forming a primer coating P onto said surface and having as general formula: X0 (meth)acrylate wherein X is either part of a preformed polymer or is an intermediate agent for polyaddition reaction or is an anchoring group for attachment of a molecule having at least one complementary reactive group. Such process allows formation of new primer by one-step electro-grafting of a reactive polymer called macromonomer.; Such process also allows further modification of an initial electrografted polymer (called primer coating) to increase the coating thickness by the so-called grafting-from technique i.e. polymerization of a second monomer or to introduce other types of polymers(also called top coating) via covalent attachment between the primer and the top coating through the X ester group by the so called grafting onto technique. Such process also allows to graft onto the primer coating compounds like functional polymer, peptide, protein, oligonucleotide, dyes, drugs, anti-bacterian compounds. [less ▲]

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See detailProcess for depositing strong adherend polymer coating onto an electrically conductive surface
Bertrand, Olivier; Jérôme, Robert ULg; Gautier, Sandrine et al

Patent (2002)

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See detailNovel bioresorbable and bioactive composites based on bioactive glass and polylactide foams for bone tissue engineering
Roether, J. A.; Gough, J. E.; Boccaccini, Aldo R. et al

in Journal of Materials Science: Materials in Medicine (2002), 13(12), 1207-1214

Bioresorbable and bioactive tissue engineering scaffolds based on bioactive glass (45S5 Bioglass®) particles and macroporous poly(DL-lactide) (PDLLA) foams were fabricated. A slurry dipping technique in ... [more ▼]

Bioresorbable and bioactive tissue engineering scaffolds based on bioactive glass (45S5 Bioglass®) particles and macroporous poly(DL-lactide) (PDLLA) foams were fabricated. A slurry dipping technique in conjunction with pretreatment in ethanol was used to achieve reproducible and well adhering bioactive glass coatings of uniform thickness on the internal and external surfaces of the foams. In vitro studies in simulated body fluid (SBF) demonstrated rapid hydroxyapatite (HA) formation on the surface of the composites, indicating their bioactivity. For comparison, composite foams containing Bioglass® particles as filler for the polymer matrix (in concentration of up to 40 wt%) were prepared by freeze-drying, enabling homogenous glass particle distribution in the polymer matrix. The formation of HA on the composite surfaces after immersion in phosphate buffer saline (PBS) was investigated to confirm the bioactivity of the composites. Human osteoblasts (HOBs) were seeded onto as-fabricated PDLLA foams and onto PDLLA foams coated with Bioglass® particles to determine early cell attachment and spreading. Cells were observed to attach and spread on all surfaces after the first 90 min in culture. The results of this study indicate that the fabricated composite materials have potential as scaffolds for guided bone regeneration. (C) 2002 Kluwer Academic Publishers. [less ▲]

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See detailDevelopment and in vitro characterisation of novel bioresorbable and bioactive composite materials based on polylactide foams and Bioglass (R) for tissue engineering applications
Roether, J. A.; Boccaccini, Aldo R.; Hench, L. L. et al

in Biomaterials (2002), 23(18), 3871-3878

Bioactive and bioresorbable composite materials were fabricated using macroporous poly(DL-lactide) (PDLLA) foams coated with and impregnated by bioactive glass (Bioglass®) particles. Stable and ... [more ▼]

Bioactive and bioresorbable composite materials were fabricated using macroporous poly(DL-lactide) (PDLLA) foams coated with and impregnated by bioactive glass (Bioglass®) particles. Stable and homogeneous Bioglasss coatings on the surface of PDLLA foams as well as infiltration of Bioglass® particles throughout the porous network were achieved using a slurry-dipping technique in conjunction with pre-treatment of the foams in ethanol. The quality of the bioactive glass coatings was reproducible in terms of thickness and microstructure. Additionally, electrophoretic deposition was investigated as an alternative method for the fabrication of PDLLA foam/Bioglass® composite materials. In vitro studies in simulated body fluid (SBF) were performed to study the formation of hydroxyapatite (HA) on the surface of PDLLA/Bioglass® composites. SEM analysis showed that the HA layer thickness rapidly increased with increasing time in SBF. The high bioactivity of the PDLLA foam/Bioglasss composites indicates the potential of the materials for use as bioactive, resorbable scaffolds in bone tissue engineering. [less ▲]

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See detailTexture characterisation of ultramacroporous materials using non-destructive methods
Blacher, Silvia ULg; Maquet, Véronique; Léonard, Angélique ULg et al

Conference (2002, May)

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See detailImage analysis characterization of highly oriented freeze-drying porous materials
Blacher, Silvia ULg; Maquet, Véronique; Jérôme, Robert ULg et al

in Image Analysis and Stereology (2002), 21

Image analysis has been used as a potential tool for the characterization of the texture of ultramacroporous foams prepared by freeze-drying. It has been shown that this technique actually provides ... [more ▼]

Image analysis has been used as a potential tool for the characterization of the texture of ultramacroporous foams prepared by freeze-drying. It has been shown that this technique actually provides valuable information on the structure of this kind of material. Image analysis of SEM micrographs of transverse sections at two different magnifications gave information on both the macroporosity (10 μm < width < 100 μm) and ultramacroporosity (width > 100 μm). Moreover, the foam anisotropy has been determined by image analysis of longitudinal sections. [less ▲]

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See detailTexture characterization of ultramacroporous materials using non-destructive methods
Blacher, Silvia ULg; Maquet, Véronique; Léonard, Angélique ULg et al

in Studies in Surface Science and Catalysis (2002), 158

Image analysis, impedance spectroscopy and X-ray microtomography have been used as non-destructive methods in order to characterize ultramacroporous materials (pore width > 1 mum). These methods are used ... [more ▼]

Image analysis, impedance spectroscopy and X-ray microtomography have been used as non-destructive methods in order to characterize ultramacroporous materials (pore width > 1 mum). These methods are used to investigate the texture of different kinds of materials, i.e., highly oriented polylactide (PLA) foams prepared by freeze-drying, isotropic polyolefin foams prepared by thermal degradation of a chemical foaming agent and convective heat dried wastewater sludges. The image analysis of SEM micrographs recorded at different magnifications gave information on the pore size distribution and pore morphology. Impedance spectroscopy was used to investigate the transport properties of the three-dimensional porous matrices by measurement of the water ionic conduction. Finally, 3D image reconstruction from 2D cross-sections obtained by X-ray microtomography allowed visualizing the pore structure. [less ▲]

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See detailPoly(D,L-lactide) foams modified by poly(ethylene oxide)-block-poly(D,L-lactide) copolymers and a-FGF: in vitro and in vivo evaluation for spinal cord regeneration
Maquet, Véronique; Martin, Didier ULg; Scholtes, Félix ULg et al

in Biomaterials (2001), 22(10), 1137-1146

The first goal of this study was to examine the influence that poly(ethylene oxide)-block-poly(D,L-lactide) (PELA) copolymer can have on the wettability, the in vitro controlled delivery capability, and ... [more ▼]

The first goal of this study was to examine the influence that poly(ethylene oxide)-block-poly(D,L-lactide) (PELA) copolymer can have on the wettability, the in vitro controlled delivery capability, and the degradation of poly(D,L-lactide) (PDLLA) foams. These foams were prepared by freeze-drying and contain micropores (10 μm) in addition of macropores (100 μm) organized longitudinally. Weight loss, water absorption, changes in molecular weight, polymolecularity (Mw/Mn) and glass transition temperature ( Tg) of PDLLA foams mixed with various amounts of PELA were followed with time. It was found that 10 wt% of PELA increased the wettability and the degradation rate of the polymer foams. The release of sulforhodamine (SR) was compared for PDLLA and PDLLA-PELA foams in relation with the foam porosity. An initial burst release was observed only in the case of the 90:10 PDLLA/PELA foam. The ability of the foam of this composition to be integrated and to promote tissue repair and axonal regeneration in the transected rat spinal cord was investigated. After implantation of ca. 20 polymer rods assembled with fibrin-glue, the polymer construct was able to bridge the cord stumps by forming a permissive support for cellular migration, angiogenesis and axonal regrowth. [less ▲]

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See detailPolylactide implants and bacterial contamination: an animal study
Mainil-Varlet, Pierre; Hauke, Christian; Maquet, Véronique et al

in Journal of Biomedical Materials Research, Part A (2001), 54(3), 335-343

Although bioresorbable aliphatic polyesters derived from lactic acid are now used clinically as sutures, bone-fracture fixation devices and sustained-release drug-delivery systems, very little is known ... [more ▼]

Although bioresorbable aliphatic polyesters derived from lactic acid are now used clinically as sutures, bone-fracture fixation devices and sustained-release drug-delivery systems, very little is known about their behavior in the infected environment. The aim of the present study was to compare the resistance to infection of two polylactide implants with different degradation characteristics, and to evaluate the influence of a bacterial challenge on their mechanical and physicochemical properties. Various quantities of a beta-haemolyzing strain of Staphylococus aureus (V 8189-94) were inoculated into the medullary cavity of rabbit tibiae, and an extruded polylactide rod composed of either P(L)LA (Poly(L-Lactide)) or P(L/DL)LA (Poly(L/DL-Lactide)) was then inserted. Animals were sacrificed four weeks after surgery. The tibiae and implants were removed under sterile conditions and evaluated microbiologically by culturing. The severity of infection was graded according to positive colony-forming units in the bone. The mechanical properties of the retrieved implants were assessed by 4-point bending and shear tests, performed in compliance with the ASTM D790 standard and their physicochemical characteristics also were characterized. P(L)LA and P(L/DL)LA implants were equally resistant to local infection, their mechanical and physicochemical properties being unaffected by bacterial challenge. Hence, once an infection has become established, the release of bactericidal/bacteriostatic by-products during implant degradation does not appear to affect its natural course. The release of bactericidal/bacteriostatic degradation products at the implantation site is unlikely to affect the natural course of an established infection. [less ▲]

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See detailImage analysis, impedance spectroscopy and mercury porosimetry characterisation of freeze-drying porous materials
Blacher, Silvia ULg; Maquet, Véronique; Pirard, René ULg et al

in Colloids and Surfaces A : Physicochemical and Engineering Aspects (2001), 187-188

Image analysis and impedance spectroscopy have been used as potential tools for the characterization of the texture of ultramacroporous PLA foams prepared by freeze-drying. It has been shown that these ... [more ▼]

Image analysis and impedance spectroscopy have been used as potential tools for the characterization of the texture of ultramacroporous PLA foams prepared by freeze-drying. It has been shown that these two techniques actually provide valuable information on the structure of this material. They are complementary to mercury porosimetry, which does not allow morphological details to be distinguished. Image analysis of SEM micrographs of transverse cross-sections at two different magnifications gave information on both the macroporosity (1 μm < width < 10 μm) and ultramacroporosity (width > 10 μm). Impedance spectroscopy was used to investigate the transport properties of the three-dimensional porous matrices by measurement of ionic conduction [less ▲]

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See detailCharacterization of porous polylactide foams by image analysis and impedance spectroscopy
Maquet, Véronique; Blacher, Silvia ULg; Pirard, René ULg et al

in Langmuir (2000), 16(26), 10463-10470

The texture of highly porous polylactide foams prepared by freeze-drying of poly-L-lactide (L-PLA) and poly-DL-lactide (DL-PLA) solutions of various concentrations was investigated by two novel ... [more ▼]

The texture of highly porous polylactide foams prepared by freeze-drying of poly-L-lactide (L-PLA) and poly-DL-lactide (DL-PLA) solutions of various concentrations was investigated by two novel methodologies, image analysis and impedance spectroscopy. Image analysis of scanning electron micrographs of transverse cross-sections at two different magnifications gave information on both the macroporosity (1 mum < width 10 <mu>m) and ultramacroporosity (width > 10 mum). Impedance spectroscopy was used to investigate the transport properties of the three-dimensional porous matrices by measurement of ionic conduction. Image analysis showed that: (a) the macroporosity, which mainly contributes to porosity, is independent of the sample composition; (b) when the concentration of the polymer solution is increased, the density of the ultramacropores decreases and their average diameter increases; (c) the distribution of the ultramacropores is more homogeneous in the semicrystalline L-PLA. foams than in the amorphous DL-PLA counterparts, in which the ultramacropores tend to make clusters. The dielectric properties changed at low frequency, in relation to modifications in the ultramacroporosity. Ultramacropores of the L-PLA foams were found to be more open and more sensitive to the concentration of the polymer solutions compared with DL-PLA. Expectedly, the mechanical properties of the PLA foams changed with the structure of the ultramacroporous network. These results encourage further investigations on the texture of porous supports, to collect pertinent information on the physical macro- and ultramacroenvironment in which cells will reside. [less ▲]

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See detailPeripheral Nerve Regeneration Using Bioresorbable Macroporous Polylactide Scaffolds
Maquet, Véronique; Martin, Didier ULg; Malgrange, Brigitte ULg et al

in Journal of Biomedical Materials Research, Part A (2000), 52(4), 639-51

The ability of DRG-derived neurons to survive and attach onto macroporous polylactide (PLA) foams was assessed in vitro. The foams were fabricated using a thermally induced polymer-solvent phase ... [more ▼]

The ability of DRG-derived neurons to survive and attach onto macroporous polylactide (PLA) foams was assessed in vitro. The foams were fabricated using a thermally induced polymer-solvent phase separation. Two types of pore structures, namely oriented or interconnected pores, can be produced, depending on the mechanism of phase separation, which in turn can be predicted by the thermodynamics of the polymer-solvent pair. Coating of the porous foams with polyvinylalcohol (PVA) considerably improved the wettability of the foams and allowed for cell culture. The in vitro biocompatibility of the PVA-coated supports was demonstrated by measuring cell viability and neuritogenesis. Microscopic observations of the cells seeded onto the polymer foams showed that the interconnected pore networks were more favorable to cell attachment than the anisotropic ones. The capacity of highly oriented foams to support in vivo peripheral nerve regeneration was studied in rats. A sciatic nerve gap of 5-mm length was bridged with a polymer implant showing macrotubes of 100 microm diameter. At 4 weeks postoperatively, the polymer implant was still present. It was well integrated and had restored an anatomic continuity. An abundant cell migration was observed at the outer surface of the polymer implant, but not within the macrotubes. This dense cellular microenvironment was found to be favorable for axogenesis. [less ▲]

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See detailPolylactide Macroporous Biodegradable Implants for Cell Transplantation. Ii. Preparation of Polylactide Foams by Liquid-Liquid Phase Separation
Schugens, C.; Maquet, Véronique; Grandfils, Christian ULg et al

in Journal of Biomedical Materials Research (1996), 30(4), 449-61

Potential of thermally induced phase separation as a porogen technique has been studied in an effort to produce a surgical implant suitable for cell transplantation. Emphasis has been placed on the liquid ... [more ▼]

Potential of thermally induced phase separation as a porogen technique has been studied in an effort to produce a surgical implant suitable for cell transplantation. Emphasis has been placed on the liquid-liquid phase separation of solutions of amorphous poly DL-lactide and semicrystalline poly L-lactide in an 87/13 dioxane/water mixture. The related temperature/composition phase diagrams have been set up by turbidimetry, and the possible occurrence of a gel has been discussed. Freeze-drying of some phase-separated polylactide solutions can produce flexible and tough foams with an isotropic morphology. Interconnected pores of 1-10 microns in diameter are expected to result from the spinodal decomposition of the polylactide solutions with formation of co-continuous phases. Thermodynamics of the polymer/solvent pair has a decisive effect on the final macroporous foams, as shown by the dependence of their porosity, density, porous morphology, and mechanical behavior on molecular weight and crystallinity of polylactide and concentration of the original solutions. On the basis of the foam characteristics, potential of the liquid-liquid phase separation (spinodal decomposition) has been compared with the solid/liquid phase separation (solvent crystallization) as a porogen technique. [less ▲]

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See detailBiodegradable and macroporous polylactide implants for cell transplantation : 1. Preparation of macroporous polylactide supports by solid-liquid phase separation
Schugens, Ch; Maquet, Véronique; Grandfils, Christian ULg et al

in Polymer (1996), 37(6), 1027-1038

Freeze-drying of polylactide solutions in 1,4-dioxane has been studied as a way to produce microcellular foams. The thermally induced phase separation has been studied in relation to several processing ... [more ▼]

Freeze-drying of polylactide solutions in 1,4-dioxane has been studied as a way to produce microcellular foams. The thermally induced phase separation has been studied in relation to several processing and formulation parameters. The effects of polymer concentration, chain stereoregularity, polymer molecular weight and cooling rate have been investigated in connection with the porous morphology and the physico-mechanical characteristics of the final foams. As a rule, bundles of channels are formed with a diameter of ~100 μ.m. They have a preferential orientation that fits the cooling direction. A porous substructure (~10 μm) is observed in the internal walls of the tubular macropores. Variations in this general porous morphology-and particularly in the porosity, density, solvent residue, mechanical resistance and degree of regularity in the spatial organization of pores-have been observed when polymer concentration in 1,4-dioxane and polylactide stereoregularity are changed. As expected, cooling rate has a strong effect on the foam morphology, which is essentially controlled by the solvent crystallization. Pores are nothing but the fingerprints of 1,4-dioxane crystallites. [less ▲]

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