自体骨髓间充质干细胞复合胶原膜修复兔膝关节全层软骨缺损的实验研究

目的研究自体骨髓间充质干细胞(m esenchym a l stem ce lls,M SC s)复合胶原膜(m ed ica l co llagenm em brane of gu ided tissue regeneration,M CM G)对兔膝关节局部全层软骨缺损的修复作用。方法实验动物选用健康的新西兰大白兔27只,3~4月龄,体重2.1~3.4 kg,每只抽取自体骨髓3~4 m l,体外分离培养后以5.5×108/m l密度种植于M CM G支架上体外培养48 h,制成M SC s/M CM G复合物,将以上27只实验动物手术制成双膝关节、股骨内髁负重区及滑车全层软骨缺损模型后,随机分成A、B、C 3组,每组各9只。A组双侧股骨内髁负重区、滑车软骨缺损处植入M CM G/M SC s复合物;B组植入单纯M CM G;C组不作任何植入,为空白组,分别于术后4、8和12周各处死3只,取材进行大体、组织学及免疫组织化学染色观察,根据关节软骨组织学半定量评分标准进行评分。结果A组术后4周即可重建关节骨软骨缺损;修复软骨在观察期内逐渐变厚,在12周内始终保持关节面及软骨下骨结构完整,为透明软骨样修复,表面光整,与周围软骨色泽相近;而B组和C组12周时仍为纤维软骨样修复,色泽浅黄,呈虫蚀样改变,仍有空洞。A组糖胺多糖及Ⅱ型胶原表达呈阳性,B、C组则明显减少。术后4、8和12周各组组织学半定量评分及术后12周大体结果显示:股骨内髁负重区与滑车修复对比差异无统计学意义(P>0.05),A组明显优于B组和C组(P<0.05);B组优于C组(P<0.05)。结论自体M SC s复合M CM G在体内环境下可形成透明软骨修复兔膝关节全层软骨缺损。M CM G符合组织工程软骨基质材料的基本要求,有望成为一种理想的用于关节全层软骨缺损修复的软骨组织工程载体材料。

ARTICULAR CARTILAGE DEFECTS REPAIRED WITH HOMOGRAFT OF MESENCHYMAL STEM CELLS SEEDED ONTO MEDICAL COLLAGEN MEMBRANE OF GUIDED TISSUE REGENERATION

OBJECTIVE: To investigate the curative effects of homograft of the mesenchymal stem cells (MSCs) compbined with the medical collagen membrane of the guided tissue regeneration(MCMG) on the full thickness defects of the articular cartilage. METHODS: MSCs derived from New Zealand rabbits aged 3-4 months weighing 2. 1-3.4 kg were cultured in vitro with a density of 5.5 x 10 (8)/ml and seeded onto MCMG. The MSC/MCMG complex was cultured for 48 h and transplanted into the full thickness defects on the inboardcondyle and trochlea. Twenty-seven healthy New Zealand rabbits were randomly divided into 3 groups of 9 rabbits in each. The cartilage defects in the inboard condyle and trochlea were filled with the auto bone marrow MSCs and MCMG complex (MSCs/ MCMG) in Group A (Management A), with only MCMG in Group B (Management B) and with nothing in Group C (Management C). Three rabbits were killed at 4, 8 and 12 weeks after operation in each group, and the reparative tissue samples evaluated grossly,histologically and immunohistochemically were graded according to the gross and histological scale. RESULTS: Four weeks after transplantation, the cartilage and subchondralbone were regenerated in Group A; for 12 weeks, the regenerated cartilage gradually thicked; 12 week after transplantation, the defect was repaired and the structures of the carticular surface and subchondral bone was.in integrity. The defects in Group A were repaired by the hyline-like tissue and the defects in Groups B and C were repaired by the fibrous tissues. Glycosaminoglycan and type II collagen in Groups A, B and C were reduced gradually. The statistical analysis on the gross at 12 weeks and the histological gradings at 4 weeks, 8 weeks and 12 weeks showed that the inboardcondylar repair had no significant difference compared with the trochlearepair(P>0. 05). Management A was significantly better than Managements B and C (P<0. 05), and Management B was better than Management C (P<0. 05). CONCLUSION: Transplantation of the MSCs combined with MCMG on the full thickness defects of the articular cartilage is a promising approach to the the treatment of cartilage defects. MCMG can satisfy the demands of the scaffold for the tissue-engineered cartilage.