CAJ | 학술논문

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 μg(0.1 μg/μl)重组质粒pIRES-hBMP2-hVEGF165；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0.8 mm、每天1次的速率进行牵引,连续牵引10 d；各组分别于固定期1、2、4、8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1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(98.86±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.
목적 관찰불동시궤전염기인대토하합골DO과정중견인구신생골골밀도여골강도적영향,탐색기인도입적최가전염시간,이획득경호적치료효과.방법 신서란대백토48지,전마하행쌍측하합골절골급견인기식입후,채용수궤구조법분성A、B、C、D4조,분별우술후즉각、술후3d(견인개시시)、견인결속시,우쌍측견인구분별주사2 μg(0.1 μg/μl)중조질립pIRES-hBMP2-hVEGF165；A、B、C3조균여전천공자격,D조단순견인불행기인전염.각조우술후3d개시이매천0.8 mm、매천1차적속솔진행견인,련속견인10 d；각조분별우고정기1、2、4、8주처사3지토자,절취하합골행X선편검측、정량CT(quantitative computer tomography,QCT)측량견인구신생골조직밀도후,장4、8주적표본진행생물역학검측.결과 각조견인간극신생골골밀도여골강도,수착고정기적연장축점증고；고정1주시,A(83.43 ±9.96)、B(92.29±11.25)、C(89.93±14.15)3조신생골골밀도조간비교,차이무통계학의의(P＞0.05),단균고우D조(70.31±3.30),차이유통계학의의(P＜0.05)；고정2、4、8주시B조골밀도(137.54±7.20、492.93±17.57、790.48±12.19)고우A조(121.44 ±9.27,396.15±15.70,603.39±16.46)、C조(125.06±7.24,464.15±15.45,764.15±17.28)、D(98.86±8.13,336.45±11.95,577.89±18.43),차이유통계학의의(P＜0.05),고정4、8주시B조생물역학각항지표균고우A、C、D조(P＜0.05).결론 재견인개시시(견인기)진행기인전염,능구획득최가적촉진신골생성적효과,제시견인기시하합골기인치료적최가시궤.
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 eiectroporation-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 biomechanical 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 ＞0.05.But the B MD 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 ± 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.