Bone is among the most frequently transplanted tissue with about 1 million procedures annually in Europe. The worldwide market of bone replacement materials is currently estimated at 5 billion € with a 10% annual growth. Despite their considerable disadvantages, including the risk of disease transfer and immunologic rejection, limited supply of bone, costs and complications, allografts and autografts account for more than 80% of total graft volume. Significant growth opportunities exist for synthetic bone grafts in association with mesenchymal stem cells from autologous or allogenic sources as alternatives to biological bone grafts in orthopaedic and maxillofacial surgery. The objectives of REBORNE is to perform clinical trials using advanced biomaterials and cells triggering bone healing in patients. In order to reach this goal, five phase II clinical studies with 20 patients are proposed in 12 clinical centres spread in 8 European countries. Three orthopaedic trials concerning the treatment of long bone fractures and osteonecrosis of the femoral head in adults or children will be conducted using bioceramics, hydrogel for percuteneous injection and stem cells from autologous or allogenic sources. Clinical research will also concern maxillofacial surgery with bone augmentation prior to dental implants and the reconstruction of cleft palates in children. The safety and efficacy of the new therapies will be assessed clinically using X-rays, CT scans and MRI as well as histology of biopsies. These ambitious clinical targets will require research and development efforts from a large consortium of top world class laboratories, SMEs manufacturing biomaterials, GMP-cell producing facilities and surgeons in hospitals as well as the consideration of ethical and regulatory issues. It is expected that REBORNE will expand the competitiveness of Europe through the patenting of new CE-marked bioproducts in the field of regenerative medicine.