[Engineering of osseous cells and bioartificial tissues]

The association of osteogenic stem cells to a synthetic carrier makes possible the elaboration of bioartificial tissue. Numerous phosphocalcic ceramics does not trigger a foreign body reaction when implanted in bone tissue and thus, a number of materials are available osteogenic stem cell carriers to replace the bone tissue. Several methods can be used to harvest these cells. Their multiplication in vitro can lead to the appearance of anomalies of their metabolism or their karyotype. The culture method also seems to have a major influence on their appearance. The presence of these anomalies could explain the variability of results in terms of bone extracellular matrix synthesis after cell reimplantation. The surgical technique used for the implantation is also of influence. A method suppressing the in vitro period has been developed to avoid any cell metabolism modification. This method allows for a very reproducible bone synthesis in ectopic site. The availability of human embryonic stem cells could help to develop cell graft techniques for bone reconstruction.