Figure 3.

Gene therapy for bone regeneration. (A) An “expedited ex vivo” bone regeneration strategy has recently been proposed in which explants of adipose tissue or muscle can be directly transduced with Ad.BMP-2 without culture. This has shown promising results in the regeneration of critical-sized rat femoral defects (Betz et al., 2008). (B) A vector for rAAV-based BMP-2 gene delivery regulated by the tetracycline-sensitive promoter (TetON) has been generated (Gafni et al., 2004). Calvarial defect bone formation was noted in mice only after the administration of Doxycycline via the drinking water to induce BMP-2 expression. This represents a novel strategy for localized inducible gene expression. (C) Local injection of rAAV-VEGF to the mandibular condyle of rats results in increased condylar growth after 60 days, as demonstrated by increased condyle width and length (Rabie et al., 2007).