应用组织工程化肌腱修复跟腱缺损

背景:间质干细胞或间质祖细胞的非造血细胞可在体内或体外分化为骨、软骨、肌肉、肌腱、脂肪及骨髓基质,这使得它们成为组织工程领域内非常有价值的种子细胞来源.目的:以骨髓间充质干细胞为种子细胞,以Ⅰ型胶原-聚羟基乙酸为支架构建组织工程化肌腱,观察其修复跟腱缺损的效果.设计,时间及地点:随机对照动物实验,于2003年在中南大学湘雅医学院进行.材料:1.5～2.5 kg健康成年家兔由中南大学湘雅医学院动物学部提供,雌雄不限.聚羟基乙酸由威高集团康利达医用制品有限公司提供.SD大鼠由中南大学实验动物学部提供.方法:提取家兔骨髓,通过离心和贴壁法培养获取骨髓间充质干细胞,将骨髓间充质干细胞进行分离、扩增.抽取SD大鼠尾腱,制备鼠尾Ⅰ型胶原溶液,并与聚羟基乙酸缝线混合培养构建胶原-聚羟基乙酸支架.将未经体外诱导的骨髓间充质干细胞接种于胶原-聚羟基乙酸支架中构建组织工程化兔肌腱模型,以不加入细胞的为对照.切开30只家兔踝部皮肤,分离出兔跟腱,造成3cm长缺损,实验组15只以自体骨髓间充质干细胞预制的组织工程化肌腱移植于缺损处,对照组15只以Ⅰ型胶原-聚羟基乙酸支架修复跟腱缺损.主要观察指标:组织工程化肌腱修复兔跟腱缺损的效果.结果:含自体骨髓间充质干细胞的Ⅰ型胶原一聚羟基乙酸支架及不含自体骨髓间充质干细胞的Ⅰ型胶原-聚羟基乙酸支架回植于体内时大体观察呈条形凝胶状.回植于体内4周后实验组和对照组均可见移植处形成条索状组织,聚羟基乙酸缝线已降解.8周时观察可见实验组组织工程化肌腱与受体肌腱组织完好连接,呈条索状.与周围其他组织无粘连,为白色、有光泽的致密腱样组织,对照组所形成的组织较实验组细小、与周围组织有粘连.结论:以骨髓间充质干细胞为种子细胞,以Ⅰ型胶原-聚羟基乙酸为支架构建的组织工程化肌腱可明显促进肌腱损伤的修复.

Tissue engineered tendon repairs achilles tendon defects

BACKGROUND:Non-hematopoietic cell of mesenchymal stem cells (MSCs) or mesenchymal progenitor cells can differentiate into bone,cartilage,muscle,tendon,fat and bone marrow matrix in vivo and in vitro,thus becoming very valuable seed cells source in the field of tissue engineering.OBJECTIVE:To construct the tissue engineered tendon withⅠcollagen-polyglycolic acid as a scaffold and bone marrow MSCs as seed cells,and to observe the effect of tissue engineered tendon on repairing achilles tendon defects. DESIGN,TIME AND SETTING:Randomized controlled animal experiment was performed in the Xiangya Medical College of Central South University in 2003.MATERIALS:Healthy adult rabbits,irrespective of genders,weighing 1.5-2.5 kg,were offered by Animal Center of Xiangya Medical College,Central South University. Polyglycolic acid were purchased from Shandong Weigao Group Kanglida Medical Products Co.,Ltd (KLD Medical).SD rats were sourced from Department of Experimental Animals,Central South University.METHODS:Rabbit bone marrow was extracted to harvest MSCs with centrrfugation and adherence method,then bone marrow MSCs were isolated and amplified. Tail tendon was extracted from SD rats and prepared into type Ⅰ collagen solution,which was mixed and suture cultured with polyglycolic acid to construct collagen-polyglycolic acid scaffold. Other bone marrow MSCs,which were not induced in vitro,were incubated on collagen-polyglycolic acid scaffold to construct tissue engineered rabbit tendon models,with those without cells serving as controls. Thirty rabbit angle skins were cut open to separate tendon and produce a 3-cm defect. Fifteen rats in the experiment group was repaired with tissue engineered tendon,which was previously prepared with autologous bone marrow MSCs,while fifteen rats in the control group was given Ⅰ collagen-polyglycolic acid scaffold.MAIN OUTCOME MEASURES:Effect of tissue engineered tendon on repairing achilles tendon defects in rabbit.RESULTS:No matter whether contains autologous bone marrow MSCs,type I collagen-polyglycolic acid scaffold transplanted into animals exhibited column gel shape by general observation. At 4 weeks following transplantation,cordlike tissues were seen in the transplantation site,polyglycolic acid suture was degraded. At 8 weeks,the tissue engineered tendon tissues were cordlike shaped,white,lustrous and dense. They were well connected with receptor tendon tissues in the experiment group,without adhesion to peripheral tissues. In the control group,the tissues were slender and adhered to peripheral tissues. CONCLUSION:Using typeⅠ collagen-polyglycolic acid as a scaffold and bone marrow MSCs as seed cells,tissue engineered tendon can dramatically promote the repair of achilles tendon defects.