References of "Grandfils, Christian"
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See detailOptimization of Synthesis Parameters for the Production of Biphasic Calcium Phosphate Ceramics via Wet Precipitation and Sol‐Gel Process
Tilkin, Rémi ULiege; Mahy, Julien ULiege; Regibeau, Nicolas ULiege et al

in ChemistrySelect (2019), 4(21), 6634-6641

During the past few years, bioceramics, like hydroxyapatite and β‐tricalcium phosphate have been widely developed for bone reconstruction. These materials have to meet strict criteria regarding ... [more ▼]

During the past few years, bioceramics, like hydroxyapatite and β‐tricalcium phosphate have been widely developed for bone reconstruction. These materials have to meet strict criteria regarding biocompatibility, degradability, and mechanical properties. This work has been focusing on the influence of synthesis parameters on the production of calcium phosphate mixes, called biphasic calcium phosphate. In this optic, powders obtained from two synthesis processes (i. e. wet precipitation and sol‐gel process) were produced. The influence of pH, Ca/P molar mixing ratio, and calcination temperature was studied. These new materials were characterized in terms of composition, thermal properties, and textural properties via X‐ray diffraction, infrared spectroscopy, scanning electronic microscopy, thermogravimetric analysis, and nitrogen adsorption‐desorption. Wet precipitation technique produces in situ mixes with different hydroxyapatite contents while the sol‐gel process ends up with ceramics contaminated by cytotoxic CaO. Wet precipitation has been demonstrated more successful to control in situ mixes with specific composition. [less ▲]

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See detailTailored-made biodegradable polymers for drug delivery and tissue engineering
Grandfils, Christian ULiege; Regibeau, Nicolas ULiege; Tilkin, Rémi ULiege et al

Scientific conference (2019, June 06)

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See detailTailored-made biodegradable polymers for drug delivery and tissue engineering
Grandfils, Christian ULiege; Vandeberg, Romain ULiege; Sevrin, Chantal ULiege et al

Scientific conference (2019, June 05)

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See detailPhosphodiester Hydrogels for Cell Scaffolding and Drug Release Applications
Dera, Raphael; Diliën, Hanne; Billen, Brecht et al

in Macromolecular Bioscience (2019), DOI: 10.1002/mabi.201900090

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See detailDevelopment of Nanovectors for the Targeted Delivery in Anopheles Mosquitoes of Drugs against Plasmodium Parasites
Siden-Kiamos, Inga; Deligianni, Elena; Spanos, Lefteris et al

Poster (2019, May 28)

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See detailDevelopment of Nanovectors for the Targeted Delivery in Anopheles Mosquitoes of Drugs against Plasmodium Parasites
Siden-Kiamos1, Inga; Deligianni, Elena; Spanos, Lefteris et al

Poster (2019, May)

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See detailDevelopment of Nanovectors for the Targeted Delivery in Anopheles Mosquitoes of Drugs against Plasmodium Parasites
Martí Coma-Cros, Elisabet; Grandfils, Christian ULiege; Sevrin, Chantal ULiege et al

in Proceeding conference of 4th World Congress on Recent Advances in Nanotechnology (RAN'19) (2019, April)

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See detailOccurrence of non-toxic bioemulsifiers during polyhydroxyalkanoate production by Pseudomonas strains valorizing crude glycerol by-product
Kourmentza, Constantina; Araujo, Diana; Sevrin, Chantal ULiege et al

in Bioresource Technology (2019), 281

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See detailDemonstration of the adhesive properties of the medium-chain-length polyhydroxyalkanoate produced by Pseudomonas chlororaphis subsp. aurantiaca from glycerol.
Pereira, Joao R.; Araujo, Diana; Marques, Ana C. et al

in International Journal of Biological Macromolecules (2019), 122

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See detailSurface modification of biodegradable microcarriers and their characterization by microscopy
Rocca, Coralie ULiege; Sevrin, Chantal ULiege; Grysan, Patrick et al

Poster (2018, December 10)

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See detailSurface analysis of new Microcarriers Tailored for Cell Therapy
Vandeberg, Romain ULiege; Grysan, Patrick; Sivashankar, krishnamoorthy et al

Poster (2018, December 10)

Several clinical studies have reported the benefit of the administration of Mesenchymal stromal cells (MSC) in various cell therapies. However, these studies have also highlighted that their routine ... [more ▼]

Several clinical studies have reported the benefit of the administration of Mesenchymal stromal cells (MSC) in various cell therapies. However, these studies have also highlighted that their routine application need urgently new cell substrates to multiply MSC in vitro in GMP conditions. Indeed, MSC are scarce in the human body. It is therefore necessary to amplify MSC in vitro to achieve clinically relevant cell doses. Microcarriers are attractive substrate. However, in practice, MSC cultivation on the microcarriers currently available on the market has been demonstrated unsuccessful. The main aim of our research relies upon the optimization of the surface properties of microcarriers promoting MSC culture in vitro. To achieve this purpose, the outer surface of microcarriers is functionalized by grafting a thin layer composed of a “smart polymer”, mostly poly N-isopropylacrylamide (pNIPAM), whose composition has been tailored to promote the adhesion and spreading of MSC with the ability to control their fast and efficient detachment following a small change in temperature. Due to particular shape of microcarriers, specific microscopy technique must be adapted to analyse the efficiency of grafting reaction. At this stage, we have demonstrated some reliable characterization methods based on Time-of-Flight and Nanoscale Secondary Ion Mass Spectrometry (ToF and NanoSIMS), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and Fluorescent Microscopy for two type of microcarriers: Dextran and Polystyrene based carriers [less ▲]

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See detailEncapsulation de protéines par procédé sol-gel pour l’application en reconstruction osseuse
Tilkin, Rémi ULiege; Regibeau, Nicolas ULiege; Grandfils, Christian ULiege et al

Conference (2018, November 21)

Ces dernières années, l’ingénierie tissulaire est devenue une des techniques les plus prometteuse pour le maintien et la reconstruction de tissus humains, voire même d’organes entiers. Cette solution est ... [more ▼]

Ces dernières années, l’ingénierie tissulaire est devenue une des techniques les plus prometteuse pour le maintien et la reconstruction de tissus humains, voire même d’organes entiers. Cette solution est fréquemment basée sur la réalisation de matrices poreuses, appelées « scaffolds ». De nombreux matériaux ont été proposés pour la conception de scaffolds, comme les biocéramiques (e.g. hydroxyapatite, β-tricalcium phosphate). Cependant, de nombreuses études ont montré que un manque de propriétés d'ostéoinduction, d’ostéogenèse et d’ostéointégrité. Cette étude vise à ajuster les propriétés de surface de biocéramiques par l’ajout d’un revêtement sol-gel de silice dans lequel seront encapsulées des protéines. Dans cette optique, l’étude de l’influence des paramètres d’encapsulation sur la cinétique de libération des protéines est une étape cruciale. L’encapsulation d’une protéine modèle (Soybean Trypsin Inhibitor) a été étudiée via deux méthodes : (1) l'imprégnation de gels de silice préalablement synthétisés, par une solution de protéine : méthode ex situ, (2) l'incorporation de la protéine lors de la synthèse du gel de silice : méthode in situ. Pour la méthode ex situ, le tétraéthylorthosilicate (TEOS) a été utilisé comme précurseur principal de la silice et le 3-(2-aminoéthylamino)propyltriméthoxysilane (EDAS) comme agent nucléant en milieu alcoolique et à pH basique. Les gels formés ont ensuite été séchés et/ou calcinés à différentes températures. Le type de traitement et la durée d'imprégnation ont été étudiés. Pour la méthode in situ, le tétraméthylorthosicilate (TMOS) a servi de précurseur au gel de silice après hydrolyse en pH acide. Les propriétés texturales des gels de silice ont été caractérisées par adsorption-désorption d'azote et porosimétrie au mercure. La cinétique de libération de la protéine a été analysée in vitro sur une durée de 4 semaines. Les résultats de porosimétrie au mercure et d’adsorption-désorption d’azote montrent que les gels ex situ présentent une structure poreuse en forme d'entonnoir (micro, méso et macropores) tandis que le gel in situ présente une structure microporeuse. Concernant la méthode ex-situ, les résultats montrent un « burst » après seulement 24 h suivi de l’établissement d’un plateau. Le pourcentage de protéine libérée après 7 jours d’incubation augmente lorsque la quantité de groupements aminés présents dans la silice diminue (i.e. augmentation de la température de calcination). L’effet du temps d’imprégnation ne se marque que dans le cas des gels contenant des fonctions amines avec une augmentation de la quantité de protéines absorbées avec le temps d’imprégnation. Pour la méthode in situ, un « burst » plus faible a été observé durant les premières 24 h, suivi par une libération continue de la protéine sur une période de 7 jours. Tilkin Rémi et Régibeau Nicolas bénéficie d’une bourse FRIA octroyée par le F.R.S.-FNRS. S. D. Lambert remercie également le FRS-FNRS pour sa position de Maître de Recherches. [less ▲]

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See detailOptimization of calcium phosphate ceramic
Tilkin, Rémi ULiege; Regibeau, Nicolas ULiege; Grandfils, Christian ULiege et al

Poster (2018, October 29)

During the past few years, tissue engineering has become one of the most promising techniques to maintain, improve, or reconstruct human tissue, even complete human organs. This solution is frequently ... [more ▼]

During the past few years, tissue engineering has become one of the most promising techniques to maintain, improve, or reconstruct human tissue, even complete human organs. This solution is frequently based on the realization of temporary porous matrices, also called "scaffolds". These materials are highly porous matrices designed to structure the development of cells, but also to guarantee the function of the implant during the regeneration process. Several materials have been proposed for the conception of scaffolds, including calcium phosphate ceramics. Among these materials, the bioceramic class is composed of hydroxyapatite (HA), Ca5(PO4)3(OH), and β-tricalcium phosphate (TCP), β-Ca3(PO4)2. These two products are frequently used, because of their chemical and structural similarity to human bones. These similarities explain good scores observed in vitro and in vivo in terms of biocompatibility and cell colonization. [less ▲]

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See detailControl of microcarrier feed time by quantitative determination of bead-to-bead transfer during hMSC cultures
Sion, Caroline; Loubière, Céline; Grandfils, Christian ULiege et al

Conference (2018, September)

Mesenchymal stem cells extracted from the Wharton’s jelly of human umbilical cords (hWJ-MSC) show increasing interest for cell therapies due to their reduced immunogenicity, high expansion capabilities ... [more ▼]

Mesenchymal stem cells extracted from the Wharton’s jelly of human umbilical cords (hWJ-MSC) show increasing interest for cell therapies due to their reduced immunogenicity, high expansion capabilities, fast growth kinetics and various growth factors synthesis capabilities. hWJ-MSC are adherent-dependent cells meaning their expansion requires colonization of available adherence surfaces. However, when confluence is almost reached, it was previously shown that MSC begin to form aggregates that can detach from the microcarriers leading to a negative impact on cell growth and functionality [1]. To solve this problem an already assessed strategy consists in the addition of fresh microcarriers during the expansion phase. Until now, no quantitative study describing this phenomenon have been reported in literature. Besides, addition of fresh new microcarriers should allow to maintain growing cell, allowing to reach a higher cell density than in a system without microcarriers feed. The aim of this study is to better control fresh microcarriers addition by quantitatively characterize bead-to-bead transfer process during MSC cultures. Aiming at this, MSC were cultivated on Cytodex-1 microcarrier in HPLsupplemented culture medium, in mixed Erlenmeyer flasks. To quantify bead-to-bead transfer homemade fluorescent Cytodex-1 were used as available adherence surfaces. DAPI nuclei and Live/Dead cell staining were performed to determine total viable cell number and number of cells per microcarrier. Cell counting was obtained from computerized analysis of fluorescent microscopy images. Using these methods, microcarrier addition time was established to maintain constant cell number per microcarrier, avoiding to reach the confluence state. Our results showed both qualitatively and quantitatively bead-to-bead transfer during microcarrier cultures. By controlling the addition of fresh microcarriers cell aggregation has been completely prevented. This procedure allowed an increase of the maximal total cell number by a factor 1.5 in comparison with a culture with only medium feed addition. [1]. Ferrari, C., et al., (2012). Limiting cell aggregation during mesenchymal stem cell expansion on microcarriers. Biotechnology progress, 28(3), 780-787 [less ▲]

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See detailEffect of mono- and dipotassium phosphate concentration on extracellular polysaccharide production by the bacterium Enterobacter A47
Reis, Patricia; Pereira, Joao; Torres, Cristiana et al

in Process Biochemistry (2018), 75

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See detailMain chain length polyhydroxyalkanoates production from fuit pulp waste by P. Chlororaphis
Pereira, Joao Ricardo; Araujo, Diana; Marques, Ana et al

Poster (2018, September)

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