摘要
目的探讨以诱导的兔骨髓基质细胞与双层PLGA支架构建组织工程骨软骨复合体,修复兔膝关节软骨及软骨下骨缺损的方法及结果。方法健康新西兰兔28只,分为三组。A组为常规培养MSCs(10只),B组为诱导培养MSCs(10只),C组为自体骨软骨块移植(8只)。密度梯度离心法获得骨髓基质干细胞(marrow-derivedstromalcells,MSCs),分别使用常规培养液和成软骨诱导条件培养液进行体外扩增传代。提取MSCs及关节软骨细胞总RNA,RT-PCR检测Ⅰ、Ⅱ型胶原表达。扫描电镜观察MSCs在PLGA双层支架上的复合与分布情况。A、B组MSCs分别与PLGA双层支架构建直径3.5mm、高3.0mm的骨软骨复合体,植入股骨髁髌骨滑车同比例骨软骨缺损区,术后第4、8、16、24周取材,进行大体观察、组织学检查和评分。结果RT-PCR见常规培养MSCs表达Ⅰ型胶原,无Ⅱ型胶原表达;诱导后MSCs表达Ⅰ、Ⅱ型胶原。扫描电镜观察MSCs在PLGA支架黏附生长良好,孔隙深处可见细胞分布。B组标本术后24周大体观察与正常软骨无明显差别,组织学检查为成熟的类透明软骨组织(4/6),优于A组(1/4)。结论MSCs具有成骨和成软骨潜能,可在基于细胞的软骨修复中作为种子细胞与双层PLGA构建组织工程骨软骨复合体,该复合体在实验动物模型中可修复关节软骨和软骨下骨缺损。
Objective The tissue-engineered composite graft was formed with induced marrow-derived stromal cells （MSCs）and PLGA double-layer scaffold. The effectiveness of this graft for the repair of osteoehondral defects in the knee of rabbits was investigated. Methods MSCs were isolated from 20 adult rabbits with density gradient eentrifugation and was divided into two groups. In group A, the MSCs were cultivated with regular medium. In group B they were cultivated with ehondrogenic differentiation medium. The mRNA of MSCs and articular cartilage cells were extracted, and the expression of mRNA fnr type Ⅰ and Ⅱ collagen was tested by RT-PCR. The distribution and compound of MSCs with PLGA double-layer scaffold was examined with scanning electron microscopy. 28 adult rabbits were divided into 3 groups, osteochondral defect of 3.5 mm in diameter and 3 to 4 mm in depth were created in the patellar groove. Group A （10 rabbits）, the MSCs cultivated with regular medium was grafted into the defects. In group B （10 rabbits）, the MSCs cultivated with chondrogenie differentiation medium was grafted into the defects, in group C （8 rabbits）, the defects were repaired with autologous osteochondral grafts as control. Specimens were harvested at 4th, 8th, 16th and 24th week post operation respectively, histological examination was performed and graded. Results For the MSCs cultivated with regular medium, the expression of mRNA for type Ⅰ collagen wasfound with RT-PCR, but no expression for 11 collagen was found. For the induced MSCs, the expression of mRNA both for type Ⅰ and type Ⅱ collagen were found. The adhesion and growth of MSCs on the PLGA double-layer scaffold were well visualized with scanning electron microscopy, and some cells were found in the deep porotic area. For the specimens of group B, no significant difference was found comparing with normal cartilage at 24th week, and the specimens were defined as matured hyaline-like cartilage （4/6）with histological examination, superior to those specimens of group A （1/4）. Conclusion The MSCs have osteogenic and chondrogenic potentiality. Combined with PLGA double-layer scaffold, it can be served as seeded cell to form tissue-engineered composite grafts, which can be used to repair osteochondral defects in rabbit models.
出处
《中华骨科杂志》
CAS
CSCD
北大核心
2005年第8期497-502,共6页
Chinese Journal of Orthopaedics
