载辛伐他汀β-磷酸三钙支架复合脂肪干细胞修复兔颅骨缺损

Repair of calvarial defect using a tissue-engineered bone with simvastatin-loaded β-tricalcium phosphate scaffold and adipose derived stem cells in rabbits

目的:应用辛伐他汀(simvastatin)作用于脂肪干细胞,研究其对细胞生长、成骨、成血管分化的影响;利用β-磷酸三钙(β-tricalcium phosphate,β-TCP)三维支架材料负载辛伐他汀,与脂肪干细胞复合,构建组织工程骨,用于兔颅骨缺损模型的修复。方法:原代培养兔脂肪干细胞(rabbit adipose-derived stem cells,rASCs),分别以含0、0.01、0.1和1μmol/L辛伐他汀的培养液培养,计数法检测细胞数目;以0、0.05、0.1μmol/L浓度辛伐他汀培养ASCs,1、7 d后,实时定量PCR检测成骨、成血管基因的表达(RUNX2、OPN、OCN、VEGF);7 d后行ALP染色;14 d后行茜素红染色。12只新西兰大白兔颅顶双侧8 mm缺损,分别以4组材料修复(A:β-TCP,B:β-TCP/Cell,C:β-TCP/Sim,D:β-TCP/Cell/Sim),每组6例,植入8周后取材,进行组织学观察。采用SPSS17.0软件包对数据进行统计学分析。结果:0.05μmol/L辛伐他汀对脂肪干细胞RUNX2、OCN、OPN和VEGF等成骨、成血管基因的表达具有明显促进作用,碱性磷酸酶染色和von Kossa染色更为明显;植入体内8周后,β-TCP/Cell/Sim组材料的成骨面积显著大于其他3组。结论:0.05μmol/L辛伐他汀在体外对ASCs具有明显的促成骨作用,载辛伐他汀β-TCP复合脂肪干细胞可促进兔颅骨缺损的修复。

PURPOSE： The osteogenic-angiogenic differentiation effects of simvastatin（Sim） were explored on adipose tissue-derived stem cells（ASCs）.A tissue-engineered bone with simvastatin loaded β-tricalcium phosphate（β-TCP） scaffold and ASCs was constructed to repair the calvarial defect in rabbits.METHODS：ASCs were obtained from the groin of rabbits.After 14 days of osteogenic inducing culture,sufficient cells were expanded for the following experiments.Cell counting was conducted to ASCs in osteogenic inducing medium containing 0,0.01,0.1 and 1 μmol/L simvastatin.Concentrations of 0.05 and 0.1 μmol/L simvastatin were administrated to ASCs for real-time PCR of angiogenesis osteogenesis related genes like RUNX2,OPN,OCN,and VEGF on day 1,7.ALP staining was performed on day 7,Alizarin red staining for calcium deposits was carried out on day 14.Bilateral critical-sized defects were created on 12 New Zealand rabbits.Four groups of tissue-engineered bone were randomly allocated to them.Group A： β-tricalcium phosphate（β-TCP）（n=6）;group B： β-TCP/Cell（n=6）;group C： β-TCP/Sim（n=6）;group D： β-TCP/Cell/Sim（n=6）.Specimens were decalcified and stained by HE 8 weeks after operation.The data was statistically analyzed using SPSS 17.0 software package.RESULTS： The use of simvastatin with the concentration of 0.05 μmol/L enhanced the expression of angiogenic-osteogenic related genes like RUNX2,OPN,OCN,and VEGF.ALP activity and von Kossa were significantly stronger in osteogenic inducing medium containing 0.05 μmol/L simvastatin.The new bone formation area of β-TCP/Cell/Sim group at 8-week after implantation was significantly larger than the other groups.CONCLUSIONS： 0.05 μmol/L simvastatin enhances the angiogenic-osteogenic differentiation of ASCs.Simvastatin loaded β-TCP scaffold and ASCs successfully repair the calvarial defect in rabbits.These results indicate a promising future in application of simvastatin for bone regeneration.Supported by National Natural Science Foundation of China（81170939） and National Basic Research Program（973 Program）（2012CB933600）.