Association cellules–matériaux pour thérapies cellulaires osseuses

Abstract

Although autologous or allogenous bone grafting materials are widely used to repair skeletal tissue, their limitations induce surgeons to look for more advanced therapies such as tissue engineering. However, bone tissue engineering still lacks proofs of clinical efficacy, possibly due to the inadequate design of the tissue-engineered constructs in relation to the natural tissue. Our aim is therefore to design an engineered construct that mimics the three main components of bone (osteoblastic cells, collagen extracellular matrix and apatite crystals). Human bone marrow contains mesenchymal stem cells that differentiate into osteoblasts. These osteoprogenitors have been cultured on calcium phosphate ceramics producing collagen extracellular matrix in vitro and inducing ectopic bone tissue formation in vivo. Cellulosic hydrogels associated to calcium phosphate particles have been used for preparing injectable bone substitutes. These injectable materials are particularly attractive for delivering osteoprogenitor cells in to bone defects using minimal invasive surgery. Bone tissue engineering using autologous MSC and biomaterials may become in future an attractive approach for the reconstruction of large bone defects in orthopaedic, spine and maxillo-facial surgeries.