Gene therapy for in vivo bone formation: recent advances.

Gene therapy has developed during the last two decades as a promising strategy for orthopaedics applications, since several different gene transfer techniques proved to be effective, both in vitro and in vivo, for the induction of bone formation. Successful results have been achieved with gene-based bone healing strategies in several preclinical studies, using different animal models. New genes and new viral and non-viral vector constructs have been developed to reduce the risks and safety issues, widening the field of possible applications and improving the potential therapeutical effects. We review the latest gene transfer technologies employed for in vivo bone formation, focusing on the recently identified network of growth factors and genes involved in the modulation of the osteogenetic process and on the variety of vectors utilized for gene delivery.