基因修饰的成骨细胞经髓芯减压移植治疗早期股骨头缺血性坏死的实验观察

目的 评价重组人肝细胞生长因子(hHGF)基因修饰的成骨细胞经髓芯减压移植促进早期股骨头缺血坏死的血管新生及局部骨修复的效果.方法 二步酶消化法和差速贴壁法分离培养胎兔成骨细胞,利用脂质体介导hHGF基因转染成骨细胞,然后通过髓芯减压移植于兔缺血坏死的股骨头内,同时设置单纯细胞移植组和髓芯减压组,于术后第2、4、8周通过CT、组织学和微血管墨汁灌注等观察血管形成及成骨情况.结果 分离培养的胎兔成骨细胞经Ⅰ型胶原和碱性磷酸酶鉴定纯度较高.hHGF基因转染成骨细胞体外及体内检测均有hHGF蛋白的表达.通过髓芯减压移植细胞8周后转基因组和单纯成骨细胞组的新生骨小梁与单纯髓芯减压组比较有差异性,而术后2、4周转基因组的新生血管数(29.5±1.6)和(34.0±1.7)较对照组(20.6±1.9)和(25.6±2.2)差异有统计学意义(P＜0.01).结论 转染hHGF基因的成骨细胞移植于缺血坏死的股骨头后,早期可促进血管新生,并增加骨形成,显著促进坏死骨修复.

Treatment of early avascular necrosis of femoral head by core decompression and transplantation of human hepatic growth factor gene-modified osteoblasts: experiment with rabbits

OBJECTIVE: To evaluate the effects of transplantation of human hepatocyte growth factor (hHGF) gene-modified osteoblasts combined with core decompression in treatment of avascular necrosis of femoral head (ANFH). METHODS: The plasmid pcDNA3.1(+)-hHGF containing hHGF gene was constructed. Osteoblasts were isolated from fetal rabbits, cultured, and transfect3d with the plasmid pcDNA3.1(+)-hHGF or blank plasmid pcDNA3.1(+), or used as controls. Thirty-six adult New Zealand rabbits were made into ANFH models, underwent core decompression, and were randomly divided into 3 groups. Group A, transplanted with osteoblasts transfected with pcDNA3.1(+)-hHGF plasmid, Group B, transplanted with osteoblasts not transfected with pcDNA3.1(+)-hHGF plasmid, and Group C, injected with PBS medium. 2, 4, and 8 weeks later samples of femoral head were obtained to undergo CT, histological examination, and capillary ink infusion so as to observe the angiogenesis and osteogenesis. RESULTS: The pcDNA3.1(+)-hHGF transfected osteoblasts showed stable expression of hHGF. The numbers of newly formed vessels of the femoral heads of the group transfected with pcDNA3.1(+)-hHGF-transfected osteoblasts 2 and 4 weeks later were (29.47 +/- 1.64) and (34.02 +/- 1.72)/cm2 respectively, both significantly higher than those of the group transfected with blank plasmid-trsansfected osteoblasts (20.61 +/- 1.91) and (25.57 + 2.20)/cm2 respectively, both P <0. 01]. Eight weeks later the numbers of mature trabecular bone and bone marrow of Groups A and B were significantly higher than those of Group C. CONCLUSION: Core decompresson combined with transplantation of HGF gene-modified osteoblasts promotes angiogenesis, enhances bone formation, and improves the restoration of avascular necrosis of femoral head.