title: Cell therapy for bone repair.
abstract: When natural bone repair mechanisms fail, autologous bone grafting is the current standard of care. The osteogenic cells and bone matrix in the graft provide the osteo-inductive and osteo-conductive properties required for successful bone repair. Bone marrow (BM) mesenchymal stem cells (MSCs) can differentiate into osteogenic cells. MSC-based cell therapy holds promise for promoting bone repair. The amount of MSCs available from iliac-crest aspirates is too small to be clinically useful, and either concentration or culture must therefore be used to expand the MSC population. MSCs can be administered alone via percutaneous injection or implanted during open surgery with a biomaterial, usually biphasic hydroxyapatite/β-calcium-triphosphate granules. Encouraging preliminary results have been obtained in patients with delayed healing of long bone fractures or avascular necrosis of the femoral head. Bone tissue engineering involves in vitro MSC culturing on biomaterials to obtain colonisation of the biomaterial and differentiation of the cells. The biomaterial-cell construct is then implanted into the zone to be treated. Few published data are available on bone tissue engineering. Much work remains to be done before determining whether this method is suitable for the routine filling of bone tissue defects. Increasing cell survival and promoting implant vascularisation are major challenges. Improved expertise with culturing techniques, together with the incorporation of regulatory requirements, will open the way to high-quality clinical trials investigating the usefulness of cell therapy as a method for achieving bone repair. Cell therapy avoids the drawbacks of autologous bone grafting, preserving the bone stock and diminishing treatment invasiveness.
authors.affiliation: Service de chirurgie orthopédique 2, hôpital Trousseau, Université François-Rabelais de Tours, CHU de Tours, 37044 Tours cedex 09, France; Inserm U957, Laboratoire de physiopathologie de la résorption osseuse et thérapie des tumeurs osseuses primitives (LPRO), Faculté de Médecine, Université de Nantes, Nantes, France. Electronic address: rosset@univ-tours.fr.
authors.forename: P
authors.initials: P
authors.lastname: Rosset
authors.affiliation: StromaLab, UMR CNRS 5273, U1031 Inserm, Établissement Français du Sang Pyrénées-Méditerranée, Université P.-Sabatier, Toulouse, France.
authors.forename: F
authors.initials: F
authors.lastname: Deschaseaux
authors.affiliation: Inserm U957, Laboratoire de physiopathologie de la résorption osseuse et thérapie des tumeurs osseuses primitives (LPRO), Faculté de Médecine, Université de Nantes, Nantes, France.
authors.forename: P
authors.initials: P
authors.lastname: Layrolle
mesh_terms: D016026:Bone Marrow Transplantation / Q000379:methods*; D001861:Bone Regeneration / Q000502:physiology; D016025:Bone Transplantation / Q000379:methods*; D001842:Bone and Bones / Q000503:physiopathology / Q000601:surgery*; D017102:Fracture Healing / Q000502:physiology*; D006801:Humans; D045164:Mesenchymal Stem Cell Transplantation; D010012:Osteogenesis / Q000502:physiology*; D023822:Tissue Engineering
keywords: Bone repair; Bone tissue engineering; Cell therapy; Humans; Mesenchymatous stem cells