Purpose: Bone grafting is still requested to fill bone defects in traumatology, or after tumor removal, but also in orthopedic surgery for spine, arthroplasty revisions, and osteotomies. Due to the limitations of auto...Purpose: Bone grafting is still requested to fill bone defects in traumatology, or after tumor removal, but also in orthopedic surgery for spine, arthroplasty revisions, and osteotomies. Due to the limitations of autografts and allografts, and the progress of biomaterial research, a large number of nonhuman bony scaffolds have been developed including synthetic calcium phosphates and highly processed xenografts. The most important parameters for bone ingrowth are the macroporosity of the scaffold with the suitable biological autologous cells and factors, optimal osteoinductive, osteointegrative and osteoconductive properties can be achieved. Methods and Results: The important factors regulating these properties are discussed in this paper, which also reports preclinical and clinical results obtained with such bone graft substitutes. Conclusions: Among different bone graft substitutes available, the porosity, the accessibility of pores, the internal surface exposed to the biological components of bone repair, are present in highly processed bovine hydroxyapatites. Compared to autografts, allografts and synthetic substitutes, they associate an initial conductivity, and a long term stability suitable for some orthopedic indications.展开更多
文摘Purpose: Bone grafting is still requested to fill bone defects in traumatology, or after tumor removal, but also in orthopedic surgery for spine, arthroplasty revisions, and osteotomies. Due to the limitations of autografts and allografts, and the progress of biomaterial research, a large number of nonhuman bony scaffolds have been developed including synthetic calcium phosphates and highly processed xenografts. The most important parameters for bone ingrowth are the macroporosity of the scaffold with the suitable biological autologous cells and factors, optimal osteoinductive, osteointegrative and osteoconductive properties can be achieved. Methods and Results: The important factors regulating these properties are discussed in this paper, which also reports preclinical and clinical results obtained with such bone graft substitutes. Conclusions: Among different bone graft substitutes available, the porosity, the accessibility of pores, the internal surface exposed to the biological components of bone repair, are present in highly processed bovine hydroxyapatites. Compared to autografts, allografts and synthetic substitutes, they associate an initial conductivity, and a long term stability suitable for some orthopedic indications.
文摘目的采用海藻酸钠凝胶(sodium alginate,A)复合异种骨的方法,构建骨组织工程载体,观察载体中细胞的生物性能及体内成骨能力,为构建效率更高的骨组织工程载体提供实验依据。方法取2只2周龄新西兰兔的骨髓,以rhBMP-2(1×10-8 mol/L)诱导培养BMSCs。取诱导后第2代BMSCs接种于1%(V/W)A中,培养4 d HE染色观察凝胶中细胞形态。将第2代BMSCs分为单纯DMEM凝胶组和含1%A的DMEM凝胶组,培养7 d后行BMP-2免疫组织化学染色观察。第2代BMSCs与2%(V/W)A的DMEM凝胶混合,负压下复合去抗原牛松质骨(xenograft bone,X),4 d后扫描电镜观察细胞生长情况。取24只裸鼠,随机分为2组(n=12),于两侧股部肌袋中分别植入BMSCs-A-X复合体作为实验组,BMSCs-X复合体作为对照组。于术后2、4周后组织学观察复合体成骨情况,图像分析系统分析各组成骨或软骨的面积百分比。结果HE染色观察,培养4 d A中BMSCs细胞形态饱满,细胞悬浮于凝胶中,可见细胞分裂和核分裂相。单纯DMEM凝胶组和含1%A的DMEM凝胶组免疫组织化学观察,细胞分裂增殖正常,伸出多种形态的突起,胞核大,核仁清晰。单纯DMEM凝胶组BMP-2表达阳性率为44.10%±3.02%;含1%A的DMEM凝胶组为42.40%±4.83%,差异无统计学意义(P>0.05)。扫描电镜观察:A均匀复合于X微孔中,不同平面均有细胞生长。植入裸鼠体内2周后,实验组及对照组中均有软骨和骨组织形成;实验组软骨面积百分比为7.31%±0.32%,骨为5.26%±0.24%;对照组软骨为2.31%±0.21%,骨为2.16%±0.22%;两组差异有统计学意义(P<0.05)。术后4周,两组软骨和新生骨小梁及骨髓组织较2周时增多;实验组软骨面积百分比为9.31%±0.31%,骨为7.26%±0.26%;对照组软骨为3.31%±0.26%,骨为2.26%±0.28%;两组差异有统计学意义(P<0.05)。术后2、4周同组间比较差异有统计学意义(P<0.05)。结论以A-X构建骨组织工程载体,符合组织工程载体的超结构原理,最大限度地承载细胞,生物性能好,对BMSCs增殖和成骨表型及相关的生物性能无不良影响,在体内成骨效率较高。
