多孔磷酸钙骨水泥与转染骨形态发生蛋白2基因的骨髓间充质干细胞复合修复股骨髁骨缺损

Construction of tissue-engineered bone by porous calcium phosphate cement with bone marrow mesenchymal stem cells transfected with bone morphogenetic protein 2 gene for repair of femoral condyle defects

背景:骨形态发生蛋白能够提高组织工程化骨的成骨能力,但如何控制骨形态发生蛋白在机体局部持续缓慢释放,是构建具有骨诱导能力组织工程化骨的关键问题。目的:观察转染骨形态发生蛋白2基因的骨髓间充质干细胞,复合多孔磷酸骨水泥构建组织工程化骨对骨缺损的修复作用。方法:取新西兰兔白12只,制作双侧股骨髁缺损模型,左侧植入转染骨形态发生蛋2基因的骨髓间充质干细胞复合多孔磷酸钙骨水泥组织工程化骨(实验组),右侧植入未转染骨形态发生蛋白2基因的骨髓间充质干细胞复合多孔磷酸钙骨水泥组织工程化骨(对照组)。植入后4,12周取双侧股骨髁,进行组织形态学分析。结果与结论:(1)Van-Gieson染色:植入4周时,实验组可见大量新生的编织骨组织形成,主要集中在材料外周孔隙;对照组仅在材料外周观察到少量新生骨组织。植入12周时,实验组外周编织骨转变为成熟的小梁骨,人工骨内部可见大量新生骨组织形成,外周区域部分支架材料吸收被新生骨组织取代;对照组植入区亦可见较多新生骨组织从材料周边区域向中心区域生长,支架材料吸收不明显;实验组不同时间点的新生骨面积均高于对照组(P<0.001);(2)免疫荧光染色:植入12周时,实验组新骨形成速率明显快于对照组(P<0.05);(3)结果表明:采用基因转染技术将骨形态发生蛋白2转染至骨髓间充质干细胞并与磷酸钙骨水泥材料复合,可显著提高组织工程化骨修复骨缺损的效果。

BACKGROUND： Bone morphogenetic protein （BMP） can improve the osteogenesis capacity of tissue-engineered bone. However, how to prolong BMP release is a key for constructing tissue-engineered bone. OBJECTIVE： To study the repair effect of porous calcium phosphate cement （CPC） with bone marrow mesenchymal stem cells transfected with BMP-2 gene on bone defects. METHODS： After modeling of bilateral femoral condyle bone defects, 12 model rabbits were given implantation of porous CPC with bone marrow mesenchymal stem cells transfected with BMP-2 on the left （experimental group） and given implantation of porous CPC with bone marrow mesenchymal stem cells on the right （control group）. Bilateral femoral condyles were taken and analyzed histologically at 4 and 12 weeks after implantation. RESULTS AND CONCLUSION： Better osteogenesis including more newly formed bone tissues and faster scaffold absorption was observed in the experimental group compared with the control group at 4 and 12 weeks after implantation. The area of newly formed bone tissues at different time and rate of bone formation at 12 weeks were significantly higher in the experimental group than in the control group （P 〈 0.001, P 〈 0.05）. These findings indicate that transfer of BMP-2 into bone marrow mesenchyrnal stem cells combined with porous CPC could increase repair of bone defects.