title: The effect of two- and three-dimensional cell culture on the chondrogenic potential of human adipose-derived mesenchymal stem cells after subcutaneous transplantation with an injectable hydrogel.
abstract: Articular cartilage is an avascular tissue composed of chondrocytes, a unique cell type responsible for abundant matrix synthesis and maintenance. When damaged, it never heals spontaneously under physiological circumstances. Therefore, the delivery of mesenchymal stem cells using hydrogel  has been considered for cartilage repair. This study aims at investigating the influence of in vitro chondrogenic differentiation of human adipose tissue-derived stem cells (hATSCs) on in vivo cartilage formation when associated with a cellulose-based self-setting hydrogel (Si-HPMC). hATSCs  were characterized for their proliferation, surface marker expression, and multipotency. The in vitro chondrogenic potential of hATSCs cultured within Si-HPMC in control or chondrogenic medium was evaluated by measuring COL2A1, ACAN, SOX9, and COMP expression by real-time PCR. Alcian blue  and type II collagen staining were also performed. To determine whether in vitro chondrogenically differentiated hATSCs may give rise to cartilage in vivo, cells differentiated as a monolayer or in pellets were finally associated with Si-HPMC and implanted subcutaneously into nude mice. Cartilage  formation was assessed histologically by alcian blue and type II collagen staining. Our data demonstrate that hATSCs exhibited proliferation and self-renewal. hATSCs also expressed typical stem cell surface markers and were able to differentiate towards the adipogenic, osteogenic, and chondrogenic  lineages. Real-time PCR and histological analysis indicated that Si-HPMC enabled chondrogenic differentiation of hATSCs in inductive medium, as demonstrated by increased expression of chondrogenic markers. In addition, histological analysis of implants showed that chondrogenically differentiated  hATSCs (monolayers or pellets) have the ability to form cartilaginous tissue, as indicated by the presence of sulphated glycosaminoglycans and type II collagen. This study therefore suggests that an in vitro induction of hATSCs in 2D was sufficient to obtain cartilaginous tissue formation  in vivo. Si-HPMC associated with autologous hATSCs could thus be a significant tool for regenerative medicine in the context of cartilage damage.
authors.affiliation: Institut National de la Santé et de la Recherche Médicale, UMRS 791, Université de Nantes, Laboratoire d'Ingénierie Ostéo-Articulaire et Dentaire, Group STEP Skeletal tissue Engineering and Physiopathology, Faculté de chirurgie dentaire, Nantes Cedex 1, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Merceron
authors.forename: Sophie
authors.initials: S
authors.lastname: Portron
authors.forename: Martial
authors.initials: M
authors.lastname: Masson
authors.forename: Julie
authors.initials: J
authors.lastname: Lesoeur
authors.forename: Borhane Hakim
authors.initials: BH
authors.lastname: Fellah
authors.forename: Olivier
authors.initials: O
authors.lastname: Gauthier
authors.forename: Olivier
authors.initials: O
authors.lastname: Geffroy
authors.forename: Pierre
authors.initials: P
authors.lastname: Weiss
authors.forename: Jérôme
authors.initials: J
authors.lastname: Guicheux
authors.forename: Claire
authors.initials: C
authors.lastname: Vinatier
mesh_terms: D000273:Adipose Tissue / Q000166:cytology*; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D020219:Chondrogenesis / Q000187:drug effects*; D005434:Flow Cytometry; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000494:pharmacology*; D059630:Mesenchymal Stem Cells / Q000166:cytology*
chemical_list: D020136:Hydrogel, Polyethylene Glycol Dimethacrylate