多层肌腱复合体结合BMSC促进肩袖腱骨界面梯度结构再生的实验研究

Rotator cuff tear is the most common cause of shoulder pain and dysfunction in population. The high retear rate after the repair of massive rotator cuff tear compromised the outcomes and the patients’ satisfaction. The decellularized allograft patch presents promising biocompatibility and mechanical properties in repairing the rotator cuff. However, the difficulties in cell infiltration and regeneration of tendon-to-bone insertion still need to be addressed. Meanwhile, BMSC applied in tendon-to-bone insertion could improve the proliferation of tenocytes and chondrocytes, combining BMSC and VEGF could further promote the differentiation of BMSC and the vascularization of the tissue, and the formation of fibrocartilage zone. Our research team designed the composite of multilayered tendon slices (COMTS) by stacking up the decellularized tendon slices and seeding BMSCs between the slices. Repair with this patch showed satisfactory biomechanical strength, and further in vitro culture found viable cells and active cell functions. Based on our previous work, this study aims to evaluate the mechanical and cell function changes of VEGF on the patch seeded with BMSCs, to establish a rabbit non-weight-bearing model of acute rotator cuff, and to compare the mechanical properties, the cell infiltration, the tendon-to-bone healing and the effect of VEGF by repairing with COMTS seeded with BMSCs. The purpose of this study is to investigate the potential of improving tendon-to-bone healing and outcomes after rotator cuff repair by combining COMTS and BMSCs.

肩袖损伤是人群肩部疼痛及功能障碍的最常见病因，其大范围撕裂的修补后再撕裂率较高，影响疗效及患者满意度。同种异体去细胞化补片修补肩袖，具有优良的生物相容性及力学性能，但修补后自体细胞浸润及腱骨界面再生困难，亟待改进。同时，将BMSC应用于腱骨界面，可促进肌腱、软骨细胞增生，其联合VEGF后可进一步促进BMSC分化及组织血管化，促进纤维软骨带的形成。课题组前期设计多层肌腱复合体补片，将多层肌腱薄片堆叠后，于层间种植BMSC。该补片修补肩袖具有良好力学强度，体外培养发现BMSC可于肌腱深层存活并发挥功能。本研究拟在前期研究基础上，在体外比较VEGF对COMTS补片结合BMSC的力学、细胞功能影响；建立兔急性肩袖损伤非负重动物模型，在体内采用COMTS补片结合BMSC修补肩袖，比较其力学性能、细胞浸润、腱骨界面愈合情况及进一步受VEGF的影响；综合探索这一技术改善腱骨愈合及肩袖修补术后效果的潜力。

肩袖损伤是人群肩部疼痛及功能障碍的最常见病因，其大范围撕裂的修补后再撕裂率较高，影响疗效及患者满意度。课题组前期设计多层肌腱复合体（Composite of multilayered tendon slices, COMTS），将多层肌腱薄片堆叠后，于层间种植BMSC。该补片修补肩袖具有良好力学强度，体外培养发现BMSC可于肌腱深层存活并发挥功能。本研究在前期研究基础上，在体外比较VEGF对COMTS补片结合BMSC的力学、细胞功能影响；建立兔急性肩袖损伤非负重动物模型，在体内采用COMTS补片结合BMSC修补肩袖，比较其力学性能、细胞浸润、腱骨界面愈合情况及进一步受VEGF的影响；综合探索这一技术改善腱骨愈合及肩袖修补术后效果的潜力。研究发现，1.0x106/ml的BMSC种植浓度可获得较0.1x106/ml、0.5x106/ml浓度的补片更高的断裂强度、刚度，种植BMSC后的COMTS补片，其肌腱相关基因表达显著增高。1.0ug/ml的VEGF浓度可获得较0.5ug/ml、2.0ug/ml浓度混合的补片更高的断裂强度、刚度。兔的体内实验表明，COMTS+BMSC+VEGF补片可以达到较直接修补、COMTS+BMSC补片更高的力学强度及刚度，组织学显示更好地胶原排列、腱骨界面连接。