骨髓间充质干细胞复合脱钙骨基质修复兔膝关节全层软骨缺损的实验

目的:研究骨髓间充质干细胞(mesenchymal stem cells, MSCs)复合脱钙骨基质(deminerized bone matrix, DBM)修复兔膝关节全层软骨缺损的疗效. 方法:MSCs取自4～6 mo龄2.5～3.5 kg的青紫兰兔,体外分离培养后种植于DBM支架上体外培养,再移植于兔膝关节全层软骨缺损模型处. 实验动物选用健康的青紫兰兔36只,随机分成A, B, C 3个处理组各12只,A处理组(MSCs/DBM)双侧股骨髁间窝软骨缺损处植入DBM吸附体外分离培养的自体MSCs复合物;B处理组(DBM)单纯植入DBM;C处理组(对照)不作任何植入. 分别于术后4, 8和12 wk各处死4只兔子,取材进行大体、组织学及免疫组化染色观察,根据关节软骨组织学计分标准进行评分,数据输入SPSS 10.0软件统计分析,比较各组的评分差异是否具有统计学意义. 结果:MSCs复合DBM所修复组织为透明软骨样修复;而单纯DBM移植组和对照组为纤维性修复. 对术后12 wk大体及组织学形态进行评分. 按完全随机设计进行方差分析和SNK-q检验,结果显示,SMCs/DBM组明显优于DBM植入组和对照组(P<0.05);DBM组优于对照组(P<0.05). 结论:运用软骨组织工程的原理,以DBM为支架材料的自体MSCs移植是一种修复软骨缺损的行之有效的方法.

Experimental study on articular cartilage defects repaired with homograft of mesenchymal stem cells seeded onto deminerized bone matrix

AIM: To investigate the curative effects of homograft of mesenchymal stem cells (MSCs) seeded onto demineralized bone matrix (DBM) on articular cartilage defects. METHODS: Mesenchymal stem cells derived from Qingzilan rabbits aged 4 to 6 months and weighed 2.5-3.5 kg were cultured in vitro and seeded onto demineralized bone matrix. The MSC/DBM complex was cultured and transplanted into full thickness defects on intercondylar fossa. Thirty six healthy Qingzilan rabbits were divided into three groups randomly with 12 in each group. The cartilage defects in the intercondylar fossa were filled with auto bone marrow mesenchymal stem cells and demineralized bone matrix complex (MSCs/DBM) in group A (management A), with only demineralized bone matrix in group B (management B) and with nothing in group C (management C). Four rabbits were killed at 4, 8 and 12 weeks after the operation in each group, and the reparative tissue samples were evaluated grossly, histologically and immunohistochemically and graded according to gross and histological scale. SPSS 10.0 software was applied to proceed the statistical analysis to find out if the differences between each group had statistical significance. RESULTS: The defects in MSCs/DBM transplantation group were repaired by hyline like tissue and the other groups were repaired by fibrous tissues. Statistical analysis of gross and histological grading scales showed that MSCs/DBM management was significantly better than DBM management and control management( P <0.05), and DBM management was better than control management ( P <0.05). CONCLUSION: Transplantation of mesenchymal stem cells seeded onto demineralized bone matrix is a promising way for the treatment of cartilage defects.