肌腱干细胞膜片构建组织工程化肌腱促进腱骨愈合的实验研究

The anterior cruciate ligament (ACL) injuries are very common in sports medicine, the poor healing outcome of bone tendon junction after ACL reconstruction surgery is the main cause for the failure of reconstruction surgery. The tissue engineering tendon gradually bring hope and become the new strategy of enhancing bone tendon junction healing. Cell sheet technique can construct formed an elastic and coherent cell sheet without external scaffold, and preserve natural physiological cell link, extracellular matrix and microinviroment, which had been applied for tissue regeneration as an alternative biomaterial in corneal, myocardial, hepatic, and periodontal tissues repair with good outcomes. Our previous study showed tendon-derived stem cells (TDSCs) were formed an elastic and coherent cell sheet without external scaffold and the TDSCs sheet promoted tendon healing. We also found that the fibrocartilage like tissue was formed in the junction between TDSCs sheet and bone. Our results also suggested that progenitor cells in the TDSCs sheet expressed higher level of osteogenic, chondrogenic and tenogenic / ligamentogenic markers compared to control (BMSCs) both before and after the same treatment for cell sheet formation. We hypothesize that the cell sheet constructed by TDSCs may augment graft healing of bone tendon junction after ACL reconstruction surgery. We consequently want to establish the optimal condition for the development of a TDSCs sheet and construct tissue engineering tendon with good biomechanical properties. The potential effect and mechanisms of this optimized TDSCs sheet on graft healing after ACL reconstruction will then be studied in a rat model. This project will provide new strategy and theory basis for the research and treatment of promoting bone tendon junction healing.

前交叉韧带（ACL）损伤是运动医学常见病，严重危害人民健康和生活。ACL重建术后移植物腱骨愈合不良是导致手术失败的主要原因。近来组织工程技术为促进腱骨愈合带来新希望。其中细胞膜技术通过体外构建不含外源性支架材料的细胞膜片，保留自然的细胞间连接、细胞外基质及微环境，已广泛用于角膜、心肌、肝脏和牙周组织的修复并取得良好效果。本课题组前期研究采用肌腱干细胞（TDSCs）构建细胞膜片成功修复损伤肌腱，并发现TDSCs细胞膜片与骨的结合部有纤维软骨样组织形成。同时，TDSCs细胞膜片的成骨、成软骨、成肌腱或韧带分化标记物表达水平明显高于骨髓间充质干细胞（BMSCs）。因此，我们假设由TDSCs细胞膜片构建组织工程化肌腱促进腱骨愈合。本课题通过在大鼠ACL重建模型基础上，优化制备TDSCs细胞膜，构建组织工程化肌腱，验证其促进腱骨愈合的作用，有望为腱骨愈合治疗提供新策略，也为其临床应用提供理论依据。

前交叉韧带(ACL)损伤是运动医学常见病,严重危害人民健康和生活。ACL重建术后移植物腱骨愈合不良是导致手术失败的主要原因。近来组织工程技术为促进腱骨愈合带来新希望。其中细胞膜技术通过体外构建不含外源性支架材料的细胞膜片,保留自然的细胞间连接、细胞外基质及微环境,已广泛用于角膜、心肌、肝脏和牙周组织的修复并取得良好效果。本课题组前期研究采用肌腱干细胞(TDSCs)构建细胞膜片成功修复损伤肌腱,并发现TDSCs细胞膜片与骨的结合部有纤维软骨样组织形成。同时,TDSCs细胞膜片的成骨、成软骨、成肌腱或韧带分化标记物表达水平明显高于骨髓间充质干细胞(BMSCs)。课题组优化CTGF诱导TDSCs成肌腱分化的最佳条件，并制备TDSCs细胞膜，构建出组织工程化肌腱。课题组将构建出的组织工程化肌腱用于大鼠ACL重建模型，结果显示组织工程化肌腱可显著促进大鼠肌腱损伤的愈合及功能性修复，并在腱骨愈合处形成移形带。