Objective: To explore the effect of silk fibroin/poly( L-lactic acid-co-e-caprolactone) [SF/P(LLA-CL)] nanofibrous scaffold on tendon-bone healing of rabbits.
Methods: SF/P(LLA-CL) nanofibrous scaffold was fabricated by electrospinning methods. The morphology of the scaffold was observed by scanning electron microscope (SEM). Pre-osteoblasts MC3T3-E1 cells were seeded on the scaffold and cultured for 1, 3, and 5 days. Cell adhesion and proliferation were also observed by SEM. Meanwhile, twenty-four New Zealand white rabbits were randomly divided into the autogenous tendon group (control group) and the autogenous tendon wrapped with SF/P(LLA-CL) scaffold group (experimental group), with twelve rabbits in each group. An extra-articular model was established, the effect was evaluated by histological examination and mechanical testing.
Results: The morphology of SF/P(LLA-CL) nanofibrous scaffold was random, with a diameter of (219.4±66.5) nm. SEM showed that the MC3T3-E1 cells seeded on the scaffold were in the normal shape, growing well, and proliferating with time course. The results of histological examination showed that inflammatory cells infltrated into the graft-host bone interface at 6 weeks after operation in both groups. Besides, the width of interface showed no significant difference between groups. At 12 weeks after operation, protruding new bone tissue could be observed at the interface in the experimental group, while scar tissue but no new bone tissue could be seen at the interface in the control group. Mechanical testing showed that there was no significant difference in the failure load and the stiffness between groups at 6 weeks after operation ( P>0.05). The failure load and the stiffness in the experimental group were significantly higher than those in the control group at 12 weeks after operation ( P<0.05).
Conclusion: The SF/P(LLA-CL) nanofibrous scaffold has good cell biocompatibility and can effectively promote tendon-bone healing, thus providing new method for modifying graft for ACL reconstruction in the clinical practice.
目的: 探讨丝素蛋白（silk fibroin，SF）/聚乳酸-聚己内酯[poly（ L-lactic acid-co-e-caprolactone），P（LLA-CL）]纳米纤维支架对兔腱-骨愈合的影响。.
方法: 通过静电纺丝技术制备 SF/P（LLA-CL）纳米纤维支架，扫描电镜观察材料形貌；并将支架与小鼠胚胎成骨细胞前体细胞 MC3T3-E1 复合培养 1、3、5 d，扫描电镜观察细胞黏附、增殖情况。取 24 只新西兰大白兔随机分为两组（ n=12），对照组采用自体肌腱、实验组采用 SF/P（LLA-CL）纤维纳米支架包裹自体肌腱建立关节外模型；术后 6、12 周采用组织学和生物力学测试评价腱-骨愈合情况。.
结果: SF/P（LLA-CL）纳米纤维支架为非取向结构，纤维直径为（219.4±66.5）nm；复合培养后，MC3T3-E1 细胞在支架上生长良好，并随时间延长细胞逐渐增多。组织学观察示，术后 6 周两组腱-骨界面均有炎性细胞浸润，界面宽度未见明显差异；12 周时实验组腱-骨界面可见新骨长入，而对照组无新骨长入。生物力学测试，术后 6 周，两组失效负荷及刚度比较差异均无统计学意义（ P>0.05）；12 周时实验组失效负荷及刚度均显著高于对照组（ P<0.05）。.
结论: SF/P（LLA-CL）纳米纤维支架具有较好的细胞相容性，能有效促进兔腱-骨愈合，为临床上 ACL 重建移植物的改良提供新思路。.
Keywords: Anterior cruciate ligament; nanofibrous scaffold; poly(L-lactic acid-co-e-caprolactone); rabbit; silk fibroin; tendon-bone healing.