Pour savoir comment effectuer et gérer un dépôt de document, consultez le « Guide abrégé – Dépôt de documents » sur le site Web de la Bibliothèque. Pour toute question, écrivez à corpus@ulaval.ca.
 

Personne :
Laroche, Gaétan

En cours de chargement...
Photo de profil

Adresse électronique

Date de naissance

Projets de recherche

Structures organisationnelles

Fonction

Nom de famille

Laroche

Prénom

Gaétan

Affiliation

Université Laval. Département de génie des mines, de la métallurgie et des matériaux

ISNI

ORCID

Identifiant Canadiana

ncf10316941

person.page.name

Résultats de recherche

Voici les éléments 1 - 5 sur 5
  • PublicationAccès libre
    Fibronectin grafting to enhance skin sealing around transcutaneous titanium implant
    (John Wiley & Sons, 2021-04-30) Bilem, Ibrahim; Ghadhab, Souhaila; Ruel, Jean; Laroche, Gaétan; Auger, François A.; Guay-Bégin, Andrée-Anne; Pauthe, Emmanuel; Chevallier, Pascale
    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 outcomes after implant insertion, has been developed. Tensile test data showed that the adhesion strength of a bio-engineered dermal tissue was significantly higher around Fn-grafted surfaces via phosphonate, as compared to untreated surfaces. This study sheds light on the importance of an appropriate selection of the linking arm to tightly control the spatial conformation of biomolecules on the material surface, and consequently cell interactions at the interface tissue/implant.
  • PublicationAccès libre
    Milkweed scaffold : a new candidate for bone cell growth
    (Taylor & Francis Online, 2019-06-17) Bilem, Ibrahim; Laroche, Gaétan; Naudé, Nicolas; Elkoun, S.; Chevallier, Pascale; Robert, Mathieu; Soulié, Simon
    This study aims to evaluate the potential of milkweed as potential candidate to construct biodegradable scaffold for bone regeneration. A mat made of milkweed, polyethylene, and polypropylene was treated with an atmospheric pressure plasma to functionalize the surface of the polymer assembly with carboxylic acid groups, which enable to conjugate bioactive molecules, while accelerating the degradation of milkweed. Degradation tests demonstrated substantial decrease of the weight of the treated polymer mat as compared to untreated one. Biological assays revealed that the polymer assembly promoted preosteoblast MC3T3 cells recruitment with a significant enhancement observed on the RGD-grafted polymer mat.
  • PublicationAccès libre
    RGD and BMP-2 mimetic peptides crosstalk enhances osteogenic commitment of human bone marrow stem cells
    (Elsevier, 2016-03-18) Bilem, Ibrahim; Laroche, Gaétan; Plawinski, Laurent; Chevallier, Pascale; Stone, E.; Durrieu, Marie-Christine
    Human bone marrow mesenchymal stem cells (hBMSCs) commitment and differentiation are dictated by bioactive molecules sequestered within their Extra Cellular Matrix (ECM). One common approach to mimic the physiological environment is to functionalize biomaterial surfaces with ECM-derived peptides able to recruit stem cells and trigger their linage-specific differentiation. The objective of this work was to investigate combinatorial effects of RGD and BMP-2 mimetic peptides on the osteogenic commitment of hBMSCs, without supplementing the media with pro-osteogenic factors. The RGD peptide promotes cell adhesion via cell transmembrane integrin receptors, while the BMP-2 peptide, corresponding to residues 73-92 of Bone Morphogenetic Protein-2, was shown to induce hBMSCs osteoblast differentiation. The immobilization of peptides on aminated glass was ascertained by X-ray Photoelectron Spectroscopy (XPS), the density of grafted peptides was quantified by fluorescence microscopy and the surface roughness was evaluated using Atomic Force Microscopy (AFM). The osteogenic commitment of hBMSCs cultured on RGD and/or BMP-2 surfaces was characterized by immunohistochemistry using STRO-1 as specific stem cells marker and Runx-2 as an earlier osteogenic marker. Biological results showed that the osteogenic commitment of hBMSCs was enhanced on bifunctionalized surfaces as compared to surfaces containing BMP-2, while on RGD surfaces cells mainly preserved their stemness character. These results demonstrated that RGD and BMP-2 mimetic peptides act synergistically to enhance hBMSCs osteogenesis without supplementing the media with osteogenic factors. These findings contribute to the development of biomimetic materials, allowing a deeper understanding of signaling pathways that govern the transition of stem cells towards the osteoblastic lineage.
  • PublicationAccès libre
    The spatial distribution of RGD and BMP-2 mimetic peptides at the subcellular scale modulates human mesenchymal stem cells osteogenesis
    (Society for Biomaterials, 2017-11-16) Bilem, Ibrahim; Plawinski, Laurent; Laroche, Gaétan; Chevallier, Pascale; Ayela, Cédric; Sone, E.; Durrieu, Marie-Christine
    Engineering artificial extracellular matrices, based on the biomimicry of the spatial distribution of proteins and growth factors within their native microenvironment, is of great importance for understanding mechanisms of bone tissue regeneration. Herein, photolithography is used to decorate glass surfaces with subcellular patterns of RGD and BMP‐2 ligands; two mimetic peptides recognized to be involved in stem cells osteogenesis. The biological relevance of well‐defined RGD and BMP‐2 patterned surfaces is evaluated by investigating the differentiation of human mesenchymal stem cells (hMSCs) into osteoblasts, in the absence of induction media. The extent of hMSCs differentiation is revealed to be dependent on both the pattern shape and the ligand type. Indeed, the spatial patterning of BMP‐2, but not RGD peptide, significantly enhances the extent of hMSCs differentiation, suggesting that geometric cues guide stem cells specification into specialized cells in a ligand type dependent manner. Such cell culture models provide an interesting tool to investigate how stem cells perceive and respond to their microenvironment and may contribute to the development of next‐generation biomaterials capable of producing clinically relevant volume of bone tissue.
  • PublicationAccès libre
    Interplay of geometric cues and RGD/BMP-2 crosstalk in directing stem cell fate
    (American Chemical Society, 2017-08-21) Bilem, Ibrahim; Laroche, Gaétan; Plawinski, Laurent; Chevallier, Pascale; Sone, E. (Eli); Durrieu, Marie-Christine
    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.