This invention relates to an osteogenic device for the de novo induction of bone formation in a mammal. The device contains at least one transforming growth factor-β3 isoform and a retention matrix. The device is introduced by direct injection or surgical implantation into an area where de novo bone formation is desired and, once implanted, the retention matrix acts to retain the TGF-β3 isoform at its place of introduction and forms a scaffold for generated bone, the induction of which is promoted by the TGF-β3 isoform. The device may be used to induce bone growth where bone has been debrided in a surgical procedure and it may also be used to transform neoplastic primary and/or metastatic secondary masses into bone thus facilitating surgical debridement thereof.