自体骨髓间充质干细胞复合壳聚糖/羟基磷灰石支架修复兔膝骨软骨缺损

摘要

目的 探讨骨髓间充质干细胞(bone mesenehymal stem cells,BMSCs)复合壳聚糖(chitosan,CS)/羟基磷灰石(hydmxyapatite,HA)支架修复兔膝关节局部骨软骨缺损.方法 选健康日本大耳白兔36只,2～3月龄,体重1.7～2.0 kg,每只抽取自体骨髓4～6ml,体外分离培养BMSCs后以2×107/ml密度植于CS/HA支架上体外培养10 h,制成BMSCs-CS/HA支架复合物.将36只实验动物手术制成右膝股骨外侧髁负重区骨缺损模型后,随机分成A、B、C 3组,每组12只.A组植入BMSCs-CS/HA复合物,B组植入单纯CS/HA支架;C组不作任何植入,为空白对照组.分别于术后6周、12周各处死6只动物,取材后进行大体、组织学观察6根据改良Wakitani评分标准进行评分,评估软骨组织的修复情况,并行成组设计方差分析.结果 A组术后6周即可重建关节软骨缺损;修复软骨在观察期内逐渐变厚,软骨下骨有少量骨修复;术后12周透明软骨样修复,表面光整,与周围软骨色泽相近,软骨下骨有部分修复.而B组和C组12周时缺损区仍为纤维软骨样纤维组织修复,色泽浅黄.术后6、12周各组组织学半定量评分显示:股骨髁负重区修复A组评分明显优于B、C组(F=27.26,P＜0.05).结论 自体BMSCs复合CS/HA支架在体内环境下可形成透明软骨修复兔膝关节负重区骨软骨缺损.%Objective To evaluate the results of the treatment of osteochondral defects on the femoral condyles by using autologous bone mesenchymal stem cells (BMSCs) combined with chitosan/ hydroxyapatite (CS/HA) bilayered scaffolds in rabbit knee joints.Methods BMSCs derived from Japanese white rabbits aged 2-3 months weighting 1.7-2.0 kg were cultured in vitro with a density of 2×107/ml and seeded onto CS/HA scaffolds.The BMSCs-CS/HA complex was cultured for 10 h and transplanted into the osteochondral defects on the femoral condyles.Thirty-six knees with osteochondral defects created in the femoral condyles were treated (A) by BMSCs combined with CS/HA scaffold, (B) by simple CS/HA scaffold or (C) left untreated, respectively.Six rabbits were sacrificed at 6 and 12 weeks after operation in each group, and the reparative tissue samples evaluated grossly, histologically according to the gross and histological scale.Results The treatment of CS/HA scaffolds improved defect filling compared with that left untreated, while the regenerated tissue was mainly fibrocartilage and showed little bone formation.When implanted with CS/HA scaffold combined with BMSCs, most of the defects were filled with a well-established layer of cartilage tissue with a little bone formation observed by HE staining and toluidine blue staining.Conclusion The BMSCs combined with CS/HA scaffolds to repair osteochondral defects on the femoral condyles is a promising approach for the treatment of osteochondral defects.