Effect of gene therapy on the expression of bone morphogenetic protein-2 during mandible distraction / 中华医学美学美容杂志

ABSTRACT

Objective To investigate the expression patterns of major bone growth factors and bone morphogenetic protein-2 (BMP2) in the distracted calluses following transfected gene during mandibular distraction osteogenesis in a rabbit model.Methods Bilateral mandibular osteotomies were performed in New-Zeland rabbits.After a latency of 3 days,the mandibles were elongated using distractors for 7 days.After the completion of distraction,the rabbits were randomly divided into 5 groups.Three animals each were sacrificed at the end of the delay phase,at 7,14,and 28 days after completion of distraction,respectively.The lengthened mandibles were harvested and processed for immunohistochemical detection of BMP2 expression,the mean optic densities and integral optical density of BMP2 positive cells were measured by computerized image analyzer.Results Elevated cellular expression of BMP2,in the distraction gap,was observed following mandibular distraction.BMP2 staining was mainly located in inflammatory cells,and the connective tissues arrounding the new bone.Their strongest expression was the 7th day,some of those growth factors expressed weakly or negatively.Conclusions Electroporation-mediated gene transfection can promote BMP2 expression effectively,which plays an important role in cell differentiation and proliferation during distraction osteo genesis.The BMP2 stimulates extracellular matrix synthesis,induces the proliferation and differentiation of fibroblasts and osteoblasts,which then promotes the new bone formation and repair.