摘要
目的观察不同时机转染基因对兔下颌骨DO过程中牵引区新生骨骨密度与骨强度的影响，探索基因导入的最佳转染时间，以获得更好的治疗效果。方法新西兰大白兔48只，全麻下行双侧下颌骨截骨及牵引器植入后，采用随机区组法分成A、B、c、D4组，分别于术后即刻、术后3d（牵引开始时）、牵引结束时，于双侧牵引区分别注射2斗g（0．1¨g／¨1）重组质粒pIRES—hBMP2-hVEGFl65；A、B、C3组均予电穿孔刺激，D组单纯牵引不行基因转染。各组于术后3d开始以每天0．8mm、每天1次的速率进行牵引，连续牵引10d；各组分别于固定期1…248周处死3只兔子，切取下颌骨行X线片检测、定量CT（quantitative computer tomography，QCT）测量牵引区新生骨组织密度后，将4、8周的标本进行生物力学检测。结果各组牵引间隙新生骨骨密度与骨强度，随着固定期的延长逐渐增高；固定I周时，A（83．43±9．96）、B（92．29±11．25）、C（89．93±14．15）3组新生骨骨密度组间比较，差异无统计学意义（P〉0．05），但均高于D组（70．31±3．30），差异有统计学意义（P〈0．05）；固定2、4、8周时B组骨密度（137．54±7．20、492．93±17．57、790．48±12．19）高于A组（121．44±9．27，396．15±15．70，603．39±16．46）、C组（125．06±7．24，464．15±15．45，764．15±17．28）、D（98．864-8．13，336．45±11．95，577．89±18．43），差异有统计学意义（P〈0．05），固定4、8周时B组生物力学各项指标均高于A、c、D组（P〈0．05）。结论在牵引开始时（牵引期）进行基因转染，能够获得最佳的促进新骨生成的效果，提示牵引期是下颌骨基因治疗的最佳时机。
Objective To investigate the effect of gene transfection at different time on bone mineral density and strength of newly formed bone in mandibular distraction gap in rabbit, so as to explore the optimal time for gene therapy and enhance the therapeutic effect. Methods 48 New-Zealand rabbits were employed to receive mandibular osteotomy and implantation of distraction devices bilaterly. Then the rabbits were randomly divided into 4 groups as Group A, B and C and D. The animals in group A, B, and C were transfected with recombinant plasmids pIRES-hBMP2-hVEGF165 via electroporation-mediated approach at latency period, distraction period, consolidation period respectively. Group D was used as control group without gene transfection. After 3 days of latency period, the distraction devices were activated at the rate of 0.8 mm per day for 10 days. Three rabbits in each group were sacrificed at lwk, 2wk, 4wk and 8wk of consolidation respectively. The mandibles were harvested and the left mandible received X-ray examination for bone healing, and quantitative computed tomography （QCT） dectection for the bone mineral density （BMD） of newly formed bone in the distraction gap. The biomechanieal properties of the new generation bone at 4 th and 8 th week of consolidation in each group were detected by three point bending test. Results The bone mineral density and the biomechanical strength of newly formed bone increased along the length of consolidation in each group. After 1 week of consolidation, there was no significant difference in BMD among group A（83.43 ± 9. 96） , group B（92.29 ± 11.25）, group C（89. 93 ± 14. 15）, P 〉 O. 05. But the BMD of group A, B and C was higher than that of group D（70. 31 ± 3.30）,P 〈0. 05. After 2wk, 4wk and 8wk of consolidation, the BMD of group B （ 137.54 ± 7.20,492.93 ± 17.57,790.48 ± 12. 19） was significantly higher than those of group A （ 121.44 ± 9.27,396. 15 ± 15.70, 603.39 ±16.46）, C（125.06 ±7.24,464.15 ±15.45,764.15 ± 17.28）, and D（98.86 ±8.13,336.45 ：t： 11.95,577.89 ±18.43 ） , P 〈 0. 05. The biomechanical parameters were also higher in group B than those of group A, C and D after four and eight weeks of consolidation（P 〈 0. 05）. Conclusion It is better to transfect gene at the beginning of distraction （ distraction period） than at other stages of DO. In this way, more remarkable effect could be obtained on new bone formation. It suggests that the distraction stage is the optimal time for gene therapy.
出处
《中华整形外科杂志》
CAS
CSCD
北大核心
2012年第6期449-453,共5页
Chinese Journal of Plastic Surgery
基金
国家自然科学基金资助项目（30600653）,四川省教育厅重点项目（11ZA239）,四川省卫生厅科研课题（100285）
关键词
电穿孔
基因疗法
下颌骨
骨生成
牵张
转染
Electroporation
Gene therapy
Mandible
Osteogenesis, distraction
Transfection
