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

doi:10.3969/j.issn.2095-4344.2016.43.003

Abstract

Abstract:

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 mesenchymal stem cells combined with porous CPC could increase repair of bone defects.

中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程

Key words: Bone Morphogenetic Proteins, Calcium Phosphates, Tissue Engineering

CLC Number:

R318

Xiao Qi-ke, Wei Yu-shan, Zhao Yi-nan, Bai Feng.

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

[J]. Chinese Journal of Tissue Engineering Research, 2016, 20(43): 6403-6408.

Figures/Tables 3

2.1 骨髓间充质干细胞的体外培养结果原代培养骨髓间充质干细胞呈圆形，与周围的血细胞相混杂。一两天后，贴壁骨髓间充质干细胞的形态逐渐延伸成梭形，即成纤维样细胞。接种1周后，可见呈放射状扩展的骨髓间充质干细胞集落形成，并逐渐与邻近集落相融合。传代培养时，骨髓间充质干细胞呈均一长梭形，旋涡状紧密排列。 2.2 基因转染与检测结果脂质体DOTAP介导BMP-2基因转染骨髓间充质干细胞，行RT-PCR，可检测出目的基因表达，pIRES-BMP-2在阳离子脂质体的作用下，成功地进入骨髓间充质干细胞，转录出相应mRNA；而作为对照的未传染细胞未见BMP-2基因表达。流式细胞仪分析转染效率为21.43%。Western Blot转染细胞的蛋白表达检测显示，转染细胞有与目的基因分子量相符的BMP-2抗体结合蛋白印迹条带，而未转染细胞没有印迹着色。 2.3 动物实验大体观察结果 1只兔术后出现感染致死，予以重新补充。其余实验兔术后植入区切口愈合良好，无渗出及感染。植入4周取材后发现，实验组兔股骨髁部缺损处有大量新生骨形成，材料与宿主骨初步融合。对照组兔股骨髁部缺损缺损边缘有少量骨形成，尚未完全修复。植入12周时，实验组骨缺损基本修复完全，新生骨与周围骨组织自然连续，植入材料部分吸收；对照组缺损区缩小，但缺损表层仍可见残留材料。 2.4 动物实验组织学观察结果植入4周时，实验组材料可见大量红染新生的编织骨组织形成，主要集中在人工骨材料外周孔隙，中心部位孔隙内有少量新骨形成，见图1A；对照组仅在人工骨材料外周观察到少量新生骨组织，但材料中心区域无骨组织形成，见图1B。植入后12周，实验组外周编织骨转变为成熟的小梁骨，人工骨内部更多的孔隙内可见新生骨组织形成，外周区域部分支架材料吸收被新生骨组织取代，见图1C；对照组在植入区内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，见图1D。"

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