半月板组织工程化修复实验研究及其生物力学问题的讨论

AN EXPERIMENTAL STUDY ON THE TISSUE-ENGINEERED REPAIR OF MENISCAL DEFECTS AND DISCUSSION ABOUT ITS BIOMECHANICAL RELEVANCE

目的 应用组织工程方法在具完全免疫功能的哺乳动物体内修复半月板缺损并讨论其生物力学问题。方法 1 5只 45天龄的长枫杂交仔猪为实验动物 ,以改良的Klagsbrun酶消化法从左膝半月板获得的自体纤维软骨细胞在体外扩增至一定数量 ,在右膝内侧副韧带前方的内侧半月板造成长 1cm的全层缺损 ,分别将PGA 纤维软骨细胞 pluronic复合物、纤维软骨细胞 pluronic复合物和单纯PGA植入缺损 ,以正常半月板和旷置缺损作为对照 ,分别于第 9周、1 6周、2 5周和 3 6周取材。标本采用大体观察、组织学、生物化学和生物力学作为评估指标。结果 PGA 细胞 pluronic复合物在大体形态、组织学结构和压弹性模量 (3 6周为正常组的 69.5 % )方面均显示形成了最佳的修复组织 ,并使对应股骨髁软骨的GAG含量 (3 6周为正常组的 5 8.3 % )保持相对稳定。结论 自体组织工程化纤维软骨在适宜的力学条件下能够修复乃至再造半月板 ,并且可以防止膝关节的创伤性退变。

Objective To repair critical sized meniscal defects in an immunocompetent mammal by tissue engineering approach and to discuss its biomechanical relevance. Methods Fifteen 45 day old Changfeng crossbred pigs were selected as experimental animals. Autologous fibrochondrocytes were obtained from left knee meniscus by modified Klagsbrun's method and were proliferated in vitro to a proper amount. A 1 cm long full layer defect of right medial meniscus was created anterior to the medial collateral ligament. PGA fibrochondrocyte pluronic complex, fibrochondrocyte pluronic complex or PGA only was respectively implanted into the defects. We used intact menisci and untreated meniscal defects as a control group. Samples obtained in 9w, 16w, 25w and 36w respectively were evaluated by macroscopy, histology, biochemistry and biomechanics. Results From the sights of macroscopic morphology, histological structure and Young's modulus (69.5% of normal meniscus at 36w), the PGA cell pluronic complex can form the best quality tissue, which can stabilize the GAG ratio (58.3% of normal cartilage at 36w) in the cartilage of medial femoral condyle. Conclusion Under a favorable mechanical circumstance, autologous tissue engineered fibrocartilage is a promising method to regenerate or reconstruct menisci, thus preventing the knee from degeneration.