腺病毒介导TGFβ1基因转染半腱肌腱重建对兔ACL术后生物力学的影响

Adenovirus-mediated gene transfer of TGF-β1 to semi-tendon in rabbits undergoing anterior cruciate ligament reconstruction

[目的]探讨腺病毒介导TGFβ1基因转染半腱肌腱重建对兔ACL术后腱骨愈合的生物力学影响。[方法]新西兰兔48只,随机分为A、B、C三组,A组自体同侧转染Ad TGFβ1的半腱肌腱;B组自体同侧转染Ad GFP的半腱肌腱;C组自体同侧半腱肌腱DMEM处理,以兔双侧后肢单股半腱肌腱转染成功后重建ACL,术后第2周、4周、8周、12周处死取材,检测生物力学特性变化。[结果]A、B组半腱肌腱转染后,均可见绿色荧光表达;A组转染12 h时半腱肌腱组织中TGF-β1蛋白表达量为(221.0±12.2)ng/ml;每组两两比较,术后第2周,A、B、C三组移植物分别出现7例、6例、7例骨隧道中拔出,1例、2例、1例撕裂,差异无统计学意义(P>0.05);术后第4周,A、B、C三组肌腱移植物分别出现6例、6例、7例骨隧道中拔出,2例、2例、1例撕裂,差异无统计学意义(P>0.05);术后第8周,A、B、C三组移植物分别出现1例、6例、6例骨隧道中拔出,7例、2例、2例撕裂,差异有统计学意义(P<0.05);术后第12周,A、B、C三组移植物分别出现1例、2例、2例骨隧道中拔出,7例、6例、6例撕裂,差异无统计学意义(P>0.05)。术后第2周,每组最大拉伸载荷差异无统计学意义(P>0.05);术后第4周、8周、12周A组的最大载荷较B、C组明显增高,差异有统计学意义(P<0.05),对比之下,A组及B组差异无统计学意义(P>0.05);随时间的推移,每组的刚度增加,但是组间差异均无统计学意义(P>0.05)。术后第2周,每组最大拉伸载荷差异无统计学意义(P>0.05);术后第4周、8周、12周A组的最大载荷较B、C组明显增高,差异有统计学意义(P<0.05),对比之下,A组及B组差异无统计学意义(P>0.05);随时间的推移,每组的刚度增加,但是组间差异均无统计学意义(P>0.05)。[结论]腺病毒介导TGFβ1基因体外转染对自体半腱肌腱重建兔ACL术后早期可提供腱骨界面强大的抗拉强度,对膝关节早期康复有重要的意义。

[objective] To investigate the outcome of adenovirus mediated gene transfer of TGF β1 to semi-tendon in rabbits undergoing anterior cruciate ligament （ACL） reconstruction. [methods] Forty-eight New Zealand rabbits were randomly divided into froup A, B, C. Animals in group A received adenovirus -mediated gene transfer of TGF β1 to autologous ipsilateral semitedon, those in group B received adenovirus mediated gene transfer of GFP to autologous ipsilateral semi-tendon, and those in group C had autologous ipsilateral semitendon treated with DMEM. ACL reconstruction was performed in rabbits after sucss gene transfer to single semi-tendon of hind legs on both sides. Rabbits were sacrificed at 2, 4, 8 and 12 weeks after surgery for evaluation of biomechanical properties. [Results] Green fluorescence was observed in group A and B after gene transfer to semi-tendon. In group A, TGF β1 protein level in semi-tendon reached 221.0- 12.2 ng/ml at 12 hours after gene transfer, at 2, 4. and 12 weeks after surgery, there were no significant differences in the number of tendon grafts pulled out of the bone tunnel or the number of ruptured tendon grafts among the three groups （7vs 6 vs 7, P〉0.05; 6vs6vs7, 2vs2vsl, P〉0.05; lvs2vs2, 7vs6vs6, P〉0.05） .At 8 weeks after surgery, group A had significantly fewer tendon grafts pulled out of the bone tunnel and significantly more ruptured tendon grafts than group B and C （ lvs6vs6, 7vs2vs2, P 〈 0.05） . At 2 weeks after surgery, there was no significant difference in the maximum load among the three groups （P〈0.05） . At 4, 8 and 12 weeks after surgery, group A had significant higher maximum load than group B and C （P 〈 0.05 ）, there was no significant difference in the maximum load between group B and C （P 〉 0.05） . After surgery, the stiffness of tendon grafts gradually increased in all three group,howew er, there was no significant difference in the stiffness among the three groups （P 〉 0.05） . [Conclusions] For rabbits un- dergoing AC1 reconstruction, adnovirus mediated gene transfer of TGF to aurtologous semi-tendon provides great anti tension strength for the tendon bone interface in the early stage, which is quite important for knee early rehabilitation.