Development of a new bone tissue-engineered product

Failures in the field of bone replacement using biomaterials, with or without bone-forming cells, or growth factors are mostly related to defective vascularization of the implants. The objective of this project was to develop a new product of tissue engineering using a macroporous and biodegradable matrix composed of polysaccharides and cells derived from adipose tissue able to differentiate towards the endothelial lineage and osteoblastic with biochemical and/or mechanical stress (culture in a bioreactor). This combination of matrix, mesenchymal stem cells, biochemical and mechanical factors aims to stimulate both bone formation and revascularization of the newly formed tissue. In vitro studies were conducted to assess the ability of differentiation of cells derived from adipose tissue to shift toward the osteoblast and endothelial lineage. Experimental studies have been conducted in mice and rats using two experimental models: the subcutaneous site in mice and a critical size bone defect in the femoral condyle in rats. Very encouraging results were obtained and the nature of the newly formed tissue was evidenced by non-invasive imaging techniques (X-ray microtomography, magnetic resonance imaging) and by standard histological methods. (C) 2011 Published by Elsevier Masson SAS.