L’impression 3D au service de la médecine régénérative du cartilage

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Influence des composés matriciels sur le signal IRM du cartilage

Texte intégral accessible uniquement aux membres de l'Université de LorraineOsteoarthritis (OA) is a common disease observed in elderly population and characterized by a progressive destruction of cartilaginous' tissue. The clinical diagnosis of this disease is realized by, converitional radiography. This method permits to visualize bone modifications related to OA disease (cysts, thickening of the subchondral bone, and osteophyts) but is unable to assess cartilage structure. Due to its high spatial resolution and high contrast between tissues, Magnetic Resonançe Imaging (MRI) is able to visualize the cartilage structure and to differentiate it from adjacent structures (bone, synovial tissue, menisci, and synovial fluid). On a 1,5T cliniciil scan, Fast Spin Echo (FSE) T2-weighted sequences, are able to show variation of internal structure (laminar appearance) of nonnal cartilage and to evaluate morphological alterations of this tissue. During maturation and aging processes, the varîations of signal intensity seem related to the modifications of matrix content and/or collagen network organization in bovine cartilage. Structural modifications of rat patellar cartilage (variation of matrix content, collagen network organization) during maturation and aging processes are studied on a 8.5T experimental imager with the T2 map technique. This quantitative tool shows a decrease of global T2 values and zonal variation of the T2 values, between the superficial and the deep zones in rat cartilage respectively. The T2 map is equally able to depict a slight or severe depletion in proteoglycans characterized by an increase of T2 values as well as in the"superficial than in the deep layers. Finally, this tool offers the opportunity to quantitatively follow the action of anti-inflammatory drugs (steroidal or no steroidal) on the cartilaginous tissue in experimental animal models.L'arthrose est une maladie commune observée dans les populations vieillissantes caràctérisée par une affection dégénérative du cartilage articulaire. Le diagnostic clinique de cette maladie passe par la radiographie conventionnelle. Cette technique permet de mettre en évidence les modifications de l'os liées à l'arthrose (géodes, condensation de l'os sous-chondral et ostéophytes) mais n'offre pas une vision directe du cartilage. Grâce à sa résolution spatiale et son contraste tissulaire élevé, l'Imagerie par Résonance Magnétique (IRM) individualise le cartilage et le différencie des structures adjacentes (os, tissu synovial, ménisques, et liquide synovial). Sur un imageur de 1,5T, les séquences Fast Spin Echo (FSE) pondérées T2 sont capables de montrer les variations de la structure interne (aspect laminaire) du cartilage normal et d'évaluer les altérations morphologiquis du tissu. Au cours du processus de maturation et de vieillissement, les variations de l'intensité du signal semblent liées aux modifications du contenu matriciel et/ou à l'organisation du réseau collagénique dans le cartilage bovin. Les modifications structurales du cartilage rotulien de rat (variation du contenu de la matrice, organisation du réseau collagénique) au cours du processus de maturation et de vieillissement ont été étudiées sur un imageur expérimental de 8,5T à l'aide de la technique de cartographie T2. Cette outil quantitatif montrent une diminution du T2 global et des variations zonales du T2 entre les zones superficielles et profondes du cartilage de rat. La cartographie T2 est capable également de détecter les faibles et fortes déplétions en protéoglycanes caractérisées par une augmentation du T2 dans les couches superficielle et profonde. Finalement, cette technique offre l'opportunité de suivre quantitativement l'action des anti-inflammatoires (stéroïdiens ou non) sur le cartilage lors de modèles expérimentaux chez l'animal

Influence des composés matriciels sur le signal IRM du cartilage

NANCY1-SCD Medecine (545472101) / SudocSudocFranceF

Both miRNA-29b downregulation and miRNA-140 overexpression drive respectively MSC proliferation and chondrogenic differentiation in collagen scaffold

RésuméInternational audienc

Biocompatibility of the bio-ink and the effect of the 3D bio-extrusion process on bone marrow mesenchymal stem cells for cartilage engineering

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Label-free relative quantification of secreted proteins as a non-invasive method for the quality control of chondrogenesis in bioengineered substitutes for cartilage repair

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Synovial tissue and systemic pharmacokinetics of rapamycin-loaded nanoparticules versus free rapamycin for articular vectorization in rat knee

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Increasing the bioactivity of elastomeric poly(epsilon-caprolactone) scaffolds for use in tissue engineering

1- articleInternational audienceBACKGROUND: Biodegradable polymers used in tissue engineering applications, such as poly(ε-caprolactone) (PCL), are hydrophobic leading to a lack of favorable cell signalization and finally to a poor cell adhesion, proliferation and differentiation. To overcome this problem, scaffolds undergo generally a surface modification. OBJECTIVE: Our laboratory has demonstrated that the grafting of poly(sodium styrene sulfonate) (pNaSS) onto titanium or poly(ethylene terephthalate) surfaces, leads to a more specific protein adsorption and a better control of cell proliferation. The objective of this work is to develop, through a straightforward way, bioactive elastomeric PCL scaffolds by grafting pNaSS. METHODS: Porous elastomeric PCL scaffolds were developed using a particulate-leaching process. pNaSS was grafted into the scaffold by a "grafting from" technique. In vitro tests were carried out to assess cell adhesion and protein expression. RESULTS: pNaSS was grafted homogeneously onto PCL scaffolds without degrading the biodegradable polymer or the porous structure. The in vitro studies have shown that pNaSS grafted onto PCL improves the cell response with a better expression of collagen, fibronectin and integrin α1. CONCLUSIONS: The grafting of pNaSS onto biomaterial surfaces is a versatile method that can provide a new generation of biodegradable scaffolds which could be "biointegrable"

Chondrogenic induction of mesenchymal stromal/stem cells from Wharton's jelly embedded in alginate hydrogel and without added growth factor: an alternative stem cell source for cartilage tissue engineering

Background: Due to their intrinsic properties, stem cells are promising tools for new developments in tissue engineering and particularly for cartilage tissue regeneration. Although mesenchymal stromal/stem cells from bone marrow (BM-MSC) have long been the most used stem cell source in cartilage tissue engineering, they have certain limits. Thanks to their properties such as low immunogenicity and particularly chondrogenic differentiation potential, mesenchymal stromal/stem cells from Wharton's jelly (WJ-MSC) promise to be an interesting source of MSC for cartilage tissue engineering. Methods: In this study, we propose to evaluate chondrogenic potential of WJ-MSC embedded in alginate/hyaluronic acid hydrogel over 28 days. Hydrogels were constructed by the original spraying method. Our main objective was to evaluate chondrogenic differentiation of WJ-MSC on three-dimensional scaffolds, without adding growth factors, at transcript and protein levels. We compared the results to those obtained from standard BM-MSC. Results: After 3 days of culture, WJ-MSC seemed to be adapted to their new three-dimensional environment without any detectable damage. From day 14 and up to 28 days, the proportion of WJ-MSC CD73(+), CD90(+), CD105(+) and CD166(+) decreased significantly compared to monolayer marker expression. Moreover, WJ MSC and BM MSC showed different phenotype profiles. After 28 days of scaffold culture, our results showed strong upregulation of cartilage-specific transcript expression. WJ-MSC exhibited greater type II collagen synthesis than BM-MSC at both transcript and protein levels. Furthermore, our work highlighted a relevant result showing that WJ-MSC expressed Runx2 and type X collagen at lower levels than BM-MSC. Conclusions: Once seeded in the hydrogel scaffold, WJ-MSC and BM-MSC have different profiles of chondrogenic differentiation at both the phenotypic level and matrix synthesis. After 4 weeks, WJ-MSC, embedded in a three-dimensional environment, were able to adapt to their environment and express specific cartilage-related genes and matrix proteins. Today, WJ-MSC represent a real alternative source of stem cells for cartilage tissue engineering.peer-reviewe

Capteur 4 canaux pour l’IRM simultanée du cartilage articulaire des 2 genoux de rat à 7T

International audienceL'IRM quantitative, IRMq, appliquée au petit animal requiert une résolution spatiale élevée, tout en offrant un rapport signal à bruit (RSB) satisfaisant. Dans l'optique de caractériser la morphologie et l'architecture matricielle du cartilage articulaire, nous avons développé un capteur multiéléments autorisant l'imagerie haute résolution (HR), à 7 Teslas, simultanée des genoux chez le rat