title: [The effect of electroporation mediated gene therapy on bone mineral density and strength of new-formed bone in mandibular distraction gap in rabbit].
abstract: OBJECTIVE
  To explore the effect of electroporation mediated gene therapy on bone mineral density and strength of new-formed bone in mandibular distraction gap, so as to enhance the osteogenesis and shorten the distraction term.
  
  
  METHODS
  New-Zealand rabbits were employed. The distraction began after 3 days of latency period at the rate of 0. 8 mm per day for 7 days. After distraction, the rabbits were randomly divided into 5 groups to receive injection in the distraction gap with recombinant plasmid 2 microg (0.1 microg/microl) pIRES-hVEGF165-hBMP2 in group A, with recombinant plasmid pIRES-hBMP2 in group B, with recombinant plasmid pIRES-hVEGF165 in group C, with pIRES in group D, and with normal saline (NS) in group E. After injection, electroporation was performed in all the groups. After 1 week, 2 weeks, 4 weeks and 8 weeks of consolidation, all the animals underwent X-ray and quantitative computed tomography (QCT). The new-formed bone in distraction gap was selected as regions of interest (ROI) to measure the bone mineral density(BMD). Then the rabbits were sacrificed and the new-formed bone samples were harvested to detect 3-point crushing strength.
  
  
  RESULTS
  BMD of newly formed bone in group A, B and C was markedly higher than that in group D and E (P < 0.01). After 2 weeks of consolidation, BMD in group A was much higher than that in the other groups, but there was no difference between group B and C. After 4 weeks of consolidation, BMD in group A and B was markedly higher than that in group C, D and E (P < 0.01). After 8 weeks of consolidation, BMD in group A was markedly higher than that in the other groups. While the BMD was not significantly different between group B and C, but the BMD in group B and C was higher than that in group D and E (P < 0.01). After 4 weeks of consolidation, the 3-point crushing strength of newly formed bone in group A was markedly higher than that in group B,C, D and E (P < 0.01), which was still the same after 8 weeks of consolidation. And the crushing strength in group B was higher than that in group C, D and E (P < 0. 05).
  
  
  CONCLUSIONS
  Electroporation-mediated transfection of recombinant plasmid pIRES-hVEGF165-hBMP2 could greatly enhance osteogenesis and calcification. A combination of VEGF and BMP may promote osteogenesis and angiogenesis simultaneously, so as to magnify the effect of each growth factor, resulting a synergetic effect.
authors.affiliation: Department of Plastic Surgery of the Affiliated Hospital of Luzhou Medical College, Luzhou 646000, China.
authors.forename: Guo-Ping
authors.initials: GP
authors.lastname: Wu
authors.forename: De-Ping
authors.initials: DP
authors.lastname: Li
authors.forename: Chun-Bing
authors.initials: CB
authors.lastname: Hu
authors.forename: Xiao-Chuan
authors.initials: XC
authors.lastname: He
authors.forename: Yong-Shu
authors.initials: YS
authors.lastname: Lan
authors.forename: Li
authors.initials: L
authors.lastname: Guo
mesh_terms: D000818:Animals; D015519:Bone Density; D001861:Bone Regeneration; D018274:Electroporation; D015316:Genetic Therapy; D008334:Mandible / Q000502:physiology / Q000601:surgery*; D019857:Osteogenesis, Distraction; D011817:Rabbits