多孔镁复合BMSC的组织工程化界面螺钉促进腱骨愈合的机制研究

As an important ligament to maintain the stability of knee joint on the front and rear, left and right directions as well as rotation, the anterior cruciate ligament (ACL) is the most likely injured ligament during the sports. With the extensive development of the mass sports and body building activities, sports injuries increased in our country. ACL reconstruction (ACLR) under the arthroscopy is a standard repair method, but the failure rate after ACLR still accounts for 10% to 20%. Failure to achieve reliable tendon-bone healing is the basic reason. Magnesium, a revolutionary implant material, has the similar mechanical properties of cancellous bone. Besides, its degradation makes the local environment full of Mg2+, which would promote the bone repair through stimulating bone formation, increasing osteoblast adhesion, inhibiting osteoclast activity and regulating bone-derived cell signaling pathway. According to our early work, a new concept interference screw would be developed in this study. Laser drilling method is used to make the magnesium interference screw with 3D porous scaffolds and chemical deposition method is used to make β-TCP coating of this screw. After the co-culture with BMSC, the interference screw modified by these kinds of tissue engineering methods is used to treat the rabbit model of ACLR with autologous extensor digitorum longus. This study would provide reliable experiment data for bone-tendon healing and theoretical basis for the use of 3D porous magnesium screw with BMSC in treating ligament reconstruction in the field of sports medicine.

前交叉韧带是维持膝关节前后、侧方以及旋转稳定性的重要韧带，因此也是运动损伤的主要受累韧带。随着我国向体育强国和全面健身运动的广泛开展，伴随的运动损伤基数巨大，关节镜下ACL重建是标准的修复方法，正在我国广泛推广，但ACL重建失败后需要翻修的仍占所有ACL重建术的10％～20％，固定失败的根本原因在于未能实现可靠的腱骨愈合。镁作为一种革命性的植入材料，力学性能与松质骨相当，并且能够在体内降解，局部的富镁环境具有刺激骨生成、提高成骨细胞粘附率、抑制破骨细胞活性、调节骨源性细胞信号传导通路的作用，促进骨修复。本课题组计划充分利用前期工作基础，通过激光钻孔法将高纯镁制成具有三维多孔支架的界面螺钉，并经化学沉积法在其表面制备β-TCP涂层，与BMSC共培养后，用以固定兔自体趾长伸肌腱重建ACL的腱骨愈合模型，通过对腱骨愈合的研究，以期为组织工程化镁金属材料在运动医学领域应用提供可靠的实验和理论支持。

前交叉韧带是维持膝关节前后、侧方以及旋转稳定性的重要韧带，因此也是运动损伤的主要受累韧带。随着我国向体育强国和全面健身运动的广泛开展，伴随的运动损伤基数巨大，关节镜下ACL重建是标准的修复方法，正在我国广泛推广，但ACL重建失败后需要翻修的仍占所有ACL重建术的10％～20％，固定失败的根本原因在于未能实现可靠的腱骨愈合。镁作为一种革命性的植入材料，力学性能与松质骨相当，并且能够在体内降解，局部的富镁环境具有刺激骨生成、提高成骨细胞粘附率、抑制破骨细胞活性、调节骨源性细胞信号传导通路的作用，促进骨修复。本课题组计划充分利用前期工作基础，通过激光钻孔法将Mg-Zn-Nd镁合金制成具有三维多孔支架的界面螺钉，并经微弧氧化在其表面制备MAO涂层，用以固定比格犬趾长屈肌腱重建ACL的腱骨愈合模型。课题研究结果显示界面螺钉（胫骨侧）在比格犬ACL重建术中固定移植肌腱的效果良好，具有较好的生物力学性能，组织学检测提示期能够促进腱骨愈合，为组织工程化镁金属材料在运动医学领域应用提供可靠的实验和理论支持。