The Effect Of Recombinant Adenovirus Vector Expressing Human Bone Morphogenetic Protein-7 On Proliferation And Differentiation Of Rabbit Marrow Stromal Cells

Large bone defects resulting from nonunion fractures or tumour resections are common clinical problems. Autogenous bone graft is the standard treatment for reducing the rate of nonunion, but this procedure is associated with significant morbidities such as donor site pain or infection, increased surgery time, and blood loss in up to 30% of individuals. Distraction osteogenesis is well-established technique for bone lengthening that has widespread clinical applications in the treatment of limb length discrepancies, bone defects, limb deformities, and fraction nonunion. Urist, in 1965, laid the foundation onto which current approaches to bone augentmation are based.Bone morphogenetic protein-7 (BMP-7), also known as osteogenic protein-1, a member of the TGF-β gene superfamily, was cloned in 1990. From then on, many investigations suggested that BMP-7 is a dimeric molecule involved in the growth, differentiation and repair of a wide variety of tissues, especially the skeletal system. Use of BMP-7 for bone regeneration represents one of the most promising emerging therapies for bone-defect and is a viable alternative to autologous and homologous bone grafts. BMP-7 has the unique ability to alter the differentiation pathway of mesenchymal cells toward chondrogenic and osteogenic lineages with the ultimate induction of endochondral bone at ectopic or orthotopic sites.Despite these encouraging studies, several factors may limit the universal use of exogenous BMP protein in skeletal regeneration. Potential obstacles to successful recombinant proteinbased regeneration include difficulties in developing suitable carriers for these proteins, producing sufficient quantities of biologically active proteins, retaining sufficient quantities of active recombinant protein in the bony lesion, and the possible absence of responsive cell populations in or near the tissues to be regenerated. Although each approach shows some promises in enhancing bone regeneration in animal and human studies, it is unlikely that any singe strategy will successfully regenerate bone in all situations. Several bone regeneration strategies are being development to restore congenital or acquired loss of bone structure and...