丝素蛋白/壳聚糖生物支架复合骨髓间质干细胞修复老年兔软骨缺损

Restoration of cartilage defect with silk fibrin/chitosan biological scaffold compound by bone marrow mesenchymal stem cells in elderly rabbits

目的 探讨丝素蛋白（SF）/壳聚糖（CS）生物支架复合诱导后骨髓间质干细胞（BMSCs）修复老年兔膝关节软骨缺损的可行性. 方法 分离培养及诱导BMSCs,将成功诱导后的BMSCs接种在SF-CS生物支架上构成修复体.54只16～18月龄兔,随机分为支架修复体组、单纯支架组和对照组,每组18只.采用右膝关节制备软骨缺损模型并植入支架.术后4、8、12周取材进行大体观察,组织学染色和改良Wakitani法组织学评分. 结果 SF-CS支架为相通性好的多孔结构,孔径平均151.72 μm,孔隙率为（92.72±4.78）％,吸水膨胀率为（141.10±6.87）％.BMSCs诱导后在SF-CS支架上生长良好,增殖活跃.12周时,支架修复体组软骨缺损基本修复,Ⅱ型胶原明显的阳性反应,生物材料基本吸收；单纯支架组以纤维样组织修复为主,Ⅱ型胶原阳性反应弱,未见支架残留；空白对照组修复不良；改良Wakitani评分显示支架修复体组优于单纯支架组和对照组（P＜0.05）.结论 SF-CS生物支架可以作为BMSCs载体修复老年兔膝关节软骨缺损.

Objective To investigate the feasibility of restoration of cartilage defect with silk fibrin/chitosan（SF-CS）biological scaffold compound by induced bone marrow mesenchymal stem cells （BMSCs）in the elderly rabbits.Methods BMSCs were extracted,cultured and induced to differentiate,then inoculated into SF-CS three-dimensional scaffold restoration.54 rabbits（aged 16-18months）were divided into scaffold restoration,single scaffold and control groups（n=18 per group）.The right knee joint was used for building cartilage defect model and implanted by scaffolds.General observation,tissue staining and modified Wakitani histological scoring were performed at 4,8 and 12weeks after operation.Results SF-CS scaffold was structured by multiple interlinked pores.The average pore size was 151.72 μm.The porosity was（92.72±4.78）%.The imbibition rate was （141.10± 6.87）%.BMSCs was grown well and proliferated dynamically in SF-CS scaffold after induction.At 12 weeks,the cartilage defect was basically repaired,type Ⅱ collagen was positively expressed and the scaffold was almost assimilated in scaffold restoration group.In single scaffold group,the cartilage defect was repaired mainly by fiber tissue,type Ⅱ collagen was less expressed and the scaffold almost degraded while the cartilage defect was repaired badly in control group.The scaffold restoration group was superior to single scaffold and control groups（P〈0.05）in improving the Wakitani score.Conclusions The SF-CS scaffold as BMSCs carrier may restore cartilage defect in knee joint of the elderly rabbits.