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Sainte-Foy-lès-Lyon, France

Claus S.,University of Lyon | Mayer N.,University of Lyon | Aubert-Foucher E.,University of Lyon | Chajra H.,Symatese Biomateriaux | And 6 more authors.
Tissue Engineering - Part C: Methods

Objective: Articular cartilage has a poor capacity for spontaneous repair. Tissue engineering approaches using biomaterials and chondrocytes offer hope for treatments. Our goal was to test whether collagen sponges could be used as scaffolds for reconstruction of cartilage with human articular chondrocytes. We investigated the effects on the nature and abundance of cartilage matrix produced of sequential addition of chosen soluble factors during cell amplification on plastic and cultivation in collagen scaffolds. Design: Isolated human articular chondrocytes were amplified for two passages with or without a cocktail of fibroblast growth factor (FGF)-2 and insulin (FI). The cells were then cultured in collagen sponges with or without a cocktail of bone morphogenetic protein (BMP)-2, insulin, and triiodothyronine (BIT). The constructs were cultivated for 36 days in vitro or for another 6-week period in a nude mouse-based contained-defect organ culture model. Gene expression was analyzed using polymerase chain reaction, and protein production was analyzed using Western-blotting and immunohistochemistry. Results: Dedifferentiation of chondrocytes occured during cell expansion on plastic, and FI stimulated this dedifferentiation. We found that addition of BIT could trigger chondrocyte redifferentiation and cartilage-characteristic matrix production in the collagen sponges. The presence of FI during cell expansion increased the chondrocyte responsiveness to BIT. © 2012 Mary Ann Liebert, Inc. Source

Claus S.,French National Center for Scientific Research | Aubert-Foucher E.,French National Center for Scientific Research | Perrier-Groult E.,French National Center for Scientific Research | Bougault C.,French National Center for Scientific Research | And 13 more authors.

Project PROMOCART (2007-2010) was adopted following the call 2006 ANR-TecSan. It was led by the laboratory of Biology and Engineering of Cartilage (Lyon), and carried out in partnership with the laboratory of Extracellular Matrix and Pathology (Caen), Lille Institute of Biology, Symatèse Biomatériaux company (Chaponost) and laboratory of Skin Substitutes (Lyon Hospital). Cartilage presents poor intrinsic healing capacity. Autologous chondrocyte implantation (ACI) is a worldwide used technique applied to focal defects of articular cartilage. However, it implies a step of cell amplification on plastic, which results in the loss of chondrocyte differentiation. The first objective of PROMOCART was to determine if bone morphogenetic protein (BMP)-2 could maintain or restore the differentiated phenotype of human chondrocytes. With the view of applying ACI to developing osteoarthritic lesions, we developed a new method of human cartilage reconstruction by using collagen sponges, BMP-2 and hypoxic culture conditions. We controlled the quality of the cellular phenotype by using new cartilage markers. © 2011 Elsevier Masson SAS. All rights reserved. Source

Rodriguez J.,Laboratoire des Substituts Cutanes | Rodriguez J.,French Institute of Health and Medical Research | Rodriguez J.,Cutaneous Substitute Laboratory | Boucher F.,University of Lyon | And 13 more authors.
Stem Cell Research and Therapy

Background: The use of stem cells from adipose tissue or adipose-derived stem cells (ASCs) in regenerative medicine could be an interesting alternative to bone marrow stem cells because they are easily accessible and available in large quantities. The aim of this study was to evaluate the potential effect of ASCs on the healing of 12 mm diameter-excisional wounds (around 110 mm2) in nude mice. Methods: Thirty nude mice underwent surgery to create one 12-mm excisional wound per mouse (spontaneous healing, n = 6; Cytocare® 532, n = 12; ASCs, n = 12). The Galiano wound model was chosen to avoid shrinkage and thus slow the spontaneous healing (SH) of mouse skin, making it closer to the physiology of human skin healing. Transparent dressings were used to enable daily healing time measurements to be taken. Immunohistochemistry, histological and blood perfusion analysis were carried out on the healed skin. Results: The in vivo results showed the effectiveness of using ASCs on reducing the time needed for complete healing to 21.2 days for SH, 17.4 days for vehicle alone (Cytocare® 532) and 14.6 days with the addition of ASCs (p < 0.001). Moreover, cutaneous perfusion of the healed wound was significantly improved in ASC-treated mice compared to SH group, as shown by laser Doppler flowmetry and the quantitation of blood vessels using immunohistochemistry of αsmooth muscle actin. Conclusions: The tolerance and efficacy of cryopreserved ASCs to accelerate the complete closure of the wound by increasing the maturation of the skin and its blood perfusion, shows their therapeutic benefit in the wound healing context. © 2015 Rodriguez et al. Source

Dos Santos M.,Laboratoire des Substituts Cutanes | Dos Santos M.,University of Lyon | Metral E.,Laboratoire des Substituts Cutanes | Boher A.,LabSkin Creations | And 4 more authors.
Matrix Biology

Skin aging is a complex phenomenon in which several mechanisms operate simultaneously. Among them, intrinsic aging is a time-dependent process, which leads to gradual skin changes affecting its structure and function such as thinning down of both epidermal and dermal compartments and a flattening and fragility of the dermo-epidermal junction. Today, several approaches have been proposed for the generation of aged skin in vitro, including skin explants from aged donors and three-dimensional skin equivalent treated by aging-inducing chemical compounds or engineered with human cells isolated from aged donors. The aim of this study was to develop and validate a new in vitro model of aging based on skin equivalent demonstrating the same phenotypic changes that were observed in chronological aging. By using prolonged culture as a proxy for cellular aging, we extended to 120 days the culture time of a skin equivalent model based on collagen-glycosaminoglycan-chitosan porous polymer and engineered with human skin cells from photo-protected sites of young donors. Morphological, immunohistological and ultrastructural analysis at different time points of the culture allowed characterizing the phenotypic changes observed in our model in comparison to samples of non photo-exposed normal human skin from different ages. We firstly confirmed that long-term cultured skin equivalents are still morphologically consistent and functionally active even after 120. days of culture. However, similar to in vivo chronological skin aging a significant decrease of the epidermis thickness as well as the number of keratinocyte expressing proliferation marker Ki67 are observed in extended culture time skin equivalent. Epidermal differentiation markers loricrin, filaggrin, involucrin and transglutaminase, also strongly decreased. Ultrastructural analysis of basement membrane showed typical features of aged skin such as duplication of lamina densa and alterations of hemidesmosomes. Moreover, the expression of hyaluronan and its surface receptor CD44 drastically decreased as observed during chronological skin aging. Finally, we found that the level of p16INK4A expression significantly increased supporting cellular senescence process associated to our model. To conclude, the major morphological and ultrastructural epidermal modifications observed in both our extended culture skin equivalent model and skin biopsies from old donors validate the relevance of our model for studying chronological aging, understanding and elucidating age-related modifications of basic skin biological processes. In addition, our model provides a unique tool for identifying new targeted molecules intended at improving the appearance of aging skin. © 2015. Source

Claus S.,University of Lyon | Claus S.,Laboratoire des Substituts Cutanes | Aubert-Foucher E.,University of Lyon | Demoor M.,University of Caen Lower Normandy | And 8 more authors.
Journal of Cellular Biochemistry

Articular cartilage is a specialized connective tissue containing chondrocytes embedded in a network of extracellular macromolecules such as type II collagen and presents poor capacity to self-repair. Autologous chondrocyte transplantation (ACT) is worldwide used for treatment of focal damage to articular cartilage. However, dedifferentiation of chondrocytes occurs during the long term culture necessary for mass cell production. The aim of this study was to investigate if addition of bone morphogenetic protein (BMP)-2, a strong inducer of chondrogenic expression, to human chondrocytes immediately after their isolation from cartilage, could help to maintain their chondrogenic phenotype in long-term culture conditions. Human articular chondrocytes were cultured according to the procedure used for ACT. Real-time PCR and Western blotting were performed to evaluate the cellular phenotype. Exogenous BMP-2 dramatically improves the chondrogenic character of knee articular chondrocytes amplified over two passages, as assessed by the BMP-2 stimulation on type II procollagen expression and synthesis. This study reveals that BMP-2 could potentially serve as a therapeutic agent for supporting the chondrogenic phenotype of human articular chondrocytes expanded in the conditions generally used for ACT. © 2010 Wiley-Liss, Inc. Source

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