References of "Colige, Alain"
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See detailChitosan-based biomimetic scaffolds and methods for preparing the same
Filée, Patrice; Freichels, Astrid ULg; Jérôme, Christine ULg et al

Patent (2011)

The invention concerns chitosan biomimetic scaffolds and methods for modulating their intrinsic properties such as rigidity, elasticity, resistance to mechanical stress, porosity, biodegradation and ... [more ▼]

The invention concerns chitosan biomimetic scaffolds and methods for modulating their intrinsic properties such as rigidity, elasticity, resistance to mechanical stress, porosity, biodegradation and absorbance of exudates. Therefore, the present invention relates to a layered chitosan scaffold wherein said layered scaffold comprises at least two fused layers, wherein at least one of the fused layers comprises a chitosan nanofiber membrane and the other fused layer comprises a porous chitosan support layer. Moreover, the present invention provides a layered chitosan scaffold characterized by (i) a good adhesion between the porous and nanofiber layers, (ii) a tuneable porosity of the nanofiber layer by tuning the distance between the nanofibers, (iii) a stable nanofibers and porous morphology even when immersed in water or other solvents and a process for the preparation of such layered chitosan scaffold. Finally, the present invention provides the use of the layered electrospun chitosan scaffold of the invention or the layered electrospun chitosan scaffold produced by the process of the invention as a wound dressing, in tissue engineering or for biomedical applications. [less ▲]

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See detailDevelopment of electrospun chitosan scaffold for wound dressing application
Aqil, Abdelhafid ULg; Tchemtchoua, Victor; Colige, Alain ULg et al

Poster (2011, November 28)

Wound dressing is one of the most promising medical applications for chitosan, due to its adhesive nature, together with some biological properties including bacteriostatic and fungistatic properties that ... [more ▼]

Wound dressing is one of the most promising medical applications for chitosan, due to its adhesive nature, together with some biological properties including bacteriostatic and fungistatic properties that help in faster wound healing. In this work we propose a chitosan biomimetic scaffolds and methods for modulating their intrinsic properties such as rigidity, elasticity, resistance to mechanical stress, porosity, biodegradation and absorbance of exudates. Therefore, the chitosan scaffold comprising at least two fused layers, wherein the advantage of a first fused layer composed of a chitosan electrospun nanofiber membrane are oxygen-permeability, high porosity, variable pore-size distribution, high surface to volume ratio, and most importantly, morphological similarity to natural extracellular matrix in skin, which promote cell adhesion migration and proliferation. The advantages of a second fused layer comprising a porous chitosan support layer are improving mechanical property, good absorption capacities to remove excess exudates and good water and gas exchange. Moreover, the scaffold was characterized by (i) a good adhesion between the porous and nanofiber layers, (ii) a tuneable porosity of the nanofiber layer by tuning the distance between the nanofibers, (iii) a stable nanofibers and porous morphology even when immersed in water. Finally, the scaffolds have shown tremendous promise as a wound dressing, in tissue engineering. The three main human cell types fibroblasts, endothelial cells and keratinocytes was cultured in vitro on electrospun nanofibers scaffold. Properties of electrospun chitosan scaffold and chitosan sponges obtained by lyophilization were also compared in vivo, in order to evaluate importance of the 3D-architecture of the biomaterial. [less ▲]

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See detailHuman papillomavirus entry into NK cells requires CD16 expression and triggers cytotoxic activity and cytokine secretion.
Renoux, Virginie ULg; Bisig, Bettina ULg; Langers, Inge ULg et al

in European journal of immunology (2011), 41(11), 3240-3252

Human papillomavirus (HPV) infections account for more than 50% of infection-linked cancers in women worldwide. The immune system controls, at least partially, viral infection and around 90% of HPV ... [more ▼]

Human papillomavirus (HPV) infections account for more than 50% of infection-linked cancers in women worldwide. The immune system controls, at least partially, viral infection and around 90% of HPV-infected women clear the virus within two years. However, it remains unclear which immune cells are implicated in this process and no study has evaluated the direct interaction between HPVs and NK cells, a key player in host resistance to viruses and tumors. We demonstrated an NK cell infiltration in HPV-associated pre-neoplastic cervical lesions. Since HPVs cannot grow in vitro, virus-like particles (VLPs) were used as a model for studying the NK cell response against the virus. Interestingly, NK cells displayed higher cytotoxic activity and cytokine production (TNF-alpha and IFN-gamma) in the presence of HPV-VLPs. Using flow cytometry and microscopy we observed that NK cell stimulation was linked to rapid VLP entry into these cells by macropinocytosis. Using CD16(+) and CD16(-) NK cell lines and a CD16-blocking antibody, we demonstrated that CD16 is necessary for HPV-VLP internalization, as well as for degranulation and cytokine production. Thus, we show for the first time that NK cells interact with HPVs and can participate in the immune response against HPV-induced lesions. [less ▲]

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See detailPlatelet-rich plasma and tendons healing: rat model
Kaux, Jean-François ULg; Drion, Pierre ULg; Colige, Alain ULg et al

in Annales de Réadaptation et de Médecine Physique (2011, October), 54(Sup 1), 125

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See detailPlasma enrichi en plaquettes et cicatrisation tendineuse : modèle sur rats
Kaux, Jean-François ULg; Drion, Pierre ULg; Colige, Alain ULg et al

in Annales de Réadaptation et de Médecine Physique (2011, October), 54(1), 123

Introduction: Le but de notre étude était de déterminer si une injection de plasma enrichi en plaquettes (PRP) pouvait améliorer et accélérer le processus de cicatrisation de tendons d'Achille de rats ... [more ▼]

Introduction: Le but de notre étude était de déterminer si une injection de plasma enrichi en plaquettes (PRP) pouvait améliorer et accélérer le processus de cicatrisation de tendons d'Achille de rats rompus. Matériel et méthode : Un défect de 5mm a été réalisé chirurgicalement au niveau de tendons d'Achille de 120 rats. Soixante rats ont reçu respectivement une infiltration de PRP ou PBS in situ après chirurgie. Vingt rats de chaque groupe ont été euthanasiés après 5, 15 et 30 jours. Quinze tendons de chaque groupe ont été directement soumis à un test de traction biomécanique jusqu'à rupture à l'aide de clamps de type "cryo-jaw" et ensuite collectés pour réaliser des analyses transcriptomiques. Des études histologique et biochimique ont également été réalisées sur les 5 tendons restant de chaque groupe. Résultats: Les tendons du groupe PRP étaient plus résistants à la rupture à 15 et 30 jours que ceux du groupe contrôle. La section transverse des tendons était significativement plus grande au sein du groupe PRP à J5 et J15. Les contraintes étaient significativement plus grandes au sein des tendons dans les phases tardives de cicatrisation. L'étude histologique montrait une augmentation de coloration pour les fibres de collagène à J5 au sein du groupe PRP, résultats confirmés par l'analyse biochimique montrant une augmentation de la concentration de collagène au sein du "cal" tendineux. L'expression de la ténomoduline, un marqueur de la différentiation des ténocytes, était significativement plus important au sein du groupe PRP à J5. Aucune différence significative en terme d'ARNm n'a été observée pou r le collagène de type III ni pour la MMP-9, à aucun temps, entre les 2 groupes. Conclusion : Une injection de PRP au sein de tendons d'Achille de rats rompus influence les phases précoces du la cicatrisation tendineuse, entrainant une meilleure résistance mécanique à la rupture. [less ▲]

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See detailTranscriptional Profiling after Lipid Raft Disruption in Keratinocytes Identifies Critical Mediators of Atopic Dermatitis Pathways
Mathay, Conny; Pierre, Michael; Depiereux, Eric et al

in Journal of Investigative Dermatology (2011), 131

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See detailEvaluation of the use of VEGF111 for the treatment of tendon lesions.
Janssen, Lauriane ULg; Kaux, Jean-François ULg; Drion, Pierre ULg et al

Poster (2011, May 20)

Alterations of tendons are common pathologies resulting from repetitive or abnormal mechanical sollicitations. Very frequently lesions become chronic and may even lead to rupture. As there is no current ... [more ▼]

Alterations of tendons are common pathologies resulting from repetitive or abnormal mechanical sollicitations. Very frequently lesions become chronic and may even lead to rupture. As there is no current efficient treatment for curing this type of diseases, new therapeutic approaches are being tested and developed. Injection of platelet-rich plasma (PRP) seems to be a promising treatment by local release of growth factors. Among these factors, VEGF-A is known to induce positive effects on vascular functions and angiogenesis, and could be implicated in the healing process of tendons. Several isoforms of VEGF-A have been described in literature, including VEGF165 and 121. VEGF111 is encoded by exons 1-4 and 8a. The lack of exon 5 enables VEGF111 to resist to proteolytic degradation and the absence of exons 6 and 7 reduces its affinity for several macromolecules present on the cell surface and in the extracellular matrix. In vivo, it has been shown to be highly proangiogenic and diffusible. A 5mm defect was surgically performed in the Achilles tendon of 60 rats. Two hours after closure of the fascia and the skin, an injection within the wound was performed with PBS alone (n=30) or with PBS containing 100 ng of VEGF111 (n=30). 10 rats of each group were sacrificed at days 5, 15 and 30. The operated tendon was then carefully removed and collected for either immunohistochemical analyses or mechanical testing. At each time point, the section and the overall appearance of the repairing tendons were similar for PBS and VEGF111-injected tendon. As compared to controls, injection of VEGF111 seemed to promote a faster angiogenesis, although the number of samples was at this stage too low for performing reliable statistical analysis. Mechanical resistance to rupture of the repairing tendons was also measured. No difference between the two groups was observed after 5 or 15 days. By contrast, increased tensile strength was clearly evidenced in the VEGF-treated group after 30 days. These preliminary data seem to indicate a positive effect of a single VEGF111 injection for restoring the mechanical properties of tendons after their section. Additional experiments are planned for confirmation purposes and for further characterizing the model. It includes a “dose- response” analysis, the use of VEGF165 as an additional control and a study evaluating the effect of several injections. [less ▲]

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See detailChitosan-based nanofibers for wound dressing
Aqil, Abdelhafid ULg; Tchemtchoua Tateu, Victor ULg; Colige, Alain ULg et al

Poster (2011, May 12)

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See detailPlatelet-rich plasma and tendons healing: rat model
Kaux, Jean-François ULg; Drion, Pierre ULg; Colige, Alain ULg et al

in Biomedica Life Science Summit (2011, April 07)

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See detailInfluence sur le tissu tendino(-musculaire) du mode de contraction en entraînement : modèle animal
Kaux, Jean-François ULg; Drion, Pierre ULg; Croisier, Jean-Louis ULg et al

in Julia, Marc; Hirt, Daniel; Croisier, Jean-Louis (Eds.) et al Tendon et jonction tendino-musculaire - De la biomécanique aux applications thérapeutiques (2011)

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See detailmicroRNA-21 Exhibits Anti-Angiogenic Function by Targeting RhoB Expression in Endothelial Cells
Sabatel, Céline; Malvaux, Ludovic; Bovy, Nicolas ULg et al

Poster (2011, February)

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See detailPlatelet-rich plasma (PRP) and tendon healing: animal model
Kaux, Jean-François ULg; Drion, Pierre ULg; Renouf, Julien et al

in British Journal of Sports Medicine (2011, February), 45(2), 1

Introduction: The tendon is a tissue which does not heal easily. Recently, several studies have demonstrated the positive effects of platelets on the healing process of tendons. A local injection of ... [more ▼]

Introduction: The tendon is a tissue which does not heal easily. Recently, several studies have demonstrated the positive effects of platelets on the healing process of tendons. A local injection of platelet–rich plasma (PRP), which releases in situ many growth factors, has the potentiality to enhance the tendon healing process. The aim of our experiment was to ascertain by an original mechanical measure whether the use of PRP was of interest for accelerating the healing process of rats’ Achilles tendons after surgical induced lesion. Methods: A 5mm defect was surgically induced in 90 rats’ Achilles tendon. Rats were divided into 2 groups of 45: (A) control (no treatment) and (B) PRP treatment. Rats of group B received a PRP injection in situ after the surgery. Afterwards, rats of both groups were placed in their cages without immobilization. After 5, 15 and 30 days, 10 traumatized Achilles tendons of each group were dissected and removed. Immediately after sampling, tendons were submitted to a biomechanical tensile test up to rupture, using a “Cryo-jaw”. After that, transcriptomic analyses were made on the tendon samples, to study the expression of type III collagen, matrix metalloproteases and tenomodulin. A hydroxyproline dosage was done to quantify the collagen in the tendon during its healing process. Tendons of the 15 remaining rats of each group were subjected to a histological study, respectively at day 5, 15 and 30 (5 rats for each time). Results: We demonstrated that the force necessary to induce tendon rupture during biomechanical tensile test study was greater for tendons which had been submitted to an injection of PRP compared to the control group: +19% (day 5), +30% (day 15) and +43% (day 30). Histological study showed that PRP could enhance cells proliferation, angiogenesis and collagen organisation. Our biochemical analyses did not explain beneficial effects of PRP. Indeed, there was no significant difference neither between the expression of different studied genes, nor in the quantity of hydroxyproline between both groups. Conclusion: This experimentation has shown that a PRP injection could accelerate the tendons healing process and improve its quality. [less ▲]

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See detailRhoGDI alpha-dependent balance between RhoA and RhoC is a key regulator of cancer cell tumorigenesis
Ho, Thi Thanh Giang ULg; Stultiens, Audrey; Dubail, Johanne ULg et al

in Molecular Biology of the Cell (2011), 22(17), 3263-75

RhoGTPases are key signaling molecules regulating main cellular functions such as migration, proliferation, survival, and gene expression through interactions with various effectors. Within the RhoA ... [more ▼]

RhoGTPases are key signaling molecules regulating main cellular functions such as migration, proliferation, survival, and gene expression through interactions with various effectors. Within the RhoA-related subclass, RhoA and RhoC contribute to several steps of tumor growth, and the regulation of their expression affects cancer progression. Our aim is to investigate their respective contributions to the acquisition of an invasive phenotype by using models of reduced or forced expression. The silencing of RhoC, but not of RhoA, increased the expression of genes encoding tumor suppressors, such as nonsteroidal anti-inflammatory drug-activated gene 1 (NAG-1), and decreased migration and the anchorage-independent growth in vitro. In vivo, RhoC small interfering RNA (siRhoC) impaired tumor growth. Of interest, the simultaneous knockdown of RhoC and NAG-1 repressed most of the siRhoC-related effects, demonstrating the central role of NAG-1. In addition of being induced by RhoC silencing, NAG-1 was also largely up-regulated in cells overexpressing RhoA. The silencing of RhoGDP dissociation inhibitor alpha (RhoGDIalpha) and the overexpression of a RhoA mutant unable to bind RhoGDIalpha suggested that the effect of RhoC silencing is indirect and results from the up-regulation of the RhoA level through competition for RhoGDIalpha. This study demonstrates the dynamic balance inside the RhoGTPase network and illustrates its biological relevance in cancer progression. [less ▲]

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