锶磷灰石多孔陶瓷复合成骨细胞的体内异位成骨研究

目的比较不同孔隙率的锶磷灰石（含5%锶的羟磷灰石,Sr-HA）陶瓷复合成骨细胞后体内异位成骨能力。方法实验试样分复合成骨细胞的不同孔隙率组和未复合成骨细胞的不同孔隙率组。先抽取健康兔的骨髓组织,体外培养,诱导分化为成骨细胞,分别与孔径约为450～700μm、孔隙率分别为50%、60%、70%的Sr-HA及孔隙率为70%的纯羟磷灰石陶瓷体复合,自体回植到兔左侧背脊肌内;未复合成骨细胞的不同孔隙率组试样则种植在兔右侧背脊肌内作为阴性对照。植入后4、12、24周取材,行大体观察、组织学检查。结果复合成骨细胞的各组陶瓷在植入兔背脊肌内4周后均有类骨质形成,随着植入时间的延长,骨组织的数量不断增加;孔隙率为70%的Sr-HA陶瓷和HA陶瓷的成骨性能明显优于50%、60%孔隙率的Sr-HA陶瓷。未复合细胞的陶瓷材料在组织学检查中未见有类骨质形成。结论Sr-HA多孔陶瓷是较理想的骨组织工程支架材料,成骨细胞复合Sr-HA陶瓷用于骨缺损的修复,具有广阔的临床应用前景。

Study on the behavior of heterotopic osteogenesis of strontium substituted hydroxyapatite compounded with osteoblasts in vivo

Objective To compare the effects of strontium substituted hydroxyapatite(Sr-HA,5 % Sr) of different porities compounded with osteoblasts on the behaviors of heterotopic osteogenesis in vivo.Methods Bone marrow was obtained from healthy rabbits cultured and induced into osteoblasts.The obtained osteoblasts were compounded with Sr-HA with different porities of 50 %,60 % and 70 % and HA with a pority of 70 %,then the composites were implanted in the left dorsal muscles of rabbits.The corresponding ceramics with the same porosities without cells were implanted in the right side of the dorsal muscles as negative controls.The implants were harvested at 4,12,or 24 weeks and prepared for histological examination to compare the amount and speed of bone formation in ceramics with different porosities.Results Examination showed obvious denovo bone formation at 4 weeks in ceramics compounded with osteoblasts and the amount of bone formation increased with time after implanting.Furthermore,the amount and speed of bone formation in ceramics with a porosity of 70 % were superior to than those of ceramics with lower porosities,but there was no obvious difference between Sr-HA ceramics and HA ceramics with porosities of 70 %.Bone formation didn't detect in any ceramics without cells by histological examination.Conclusion The Sr-HA is an optimal scaffold material for bone tissue engineering,which can be potentially applied in clinical practice for bone defect repair by compounding with osteoblasts.