丝素蛋白／羟基磷灰石细胞相容性及异位成骨作用

The cellular compatibility and the ectopic bone formation of silk fibroin/hydroxyapatite

目的观察两种丝素蛋白／羟基磷灰石（SF／HA）的细胞相容性及异位成骨作用。方法相差显微镜及扫描电镜观察兔骨髓基质细胞（BMSCs）在两种SF／HA上的生长；测定ALP活性及噻唑蓝（MTT）比色法测定细胞增殖；材料浸提液的细胞毒性试验。将成骨诱导的兔BMSCs与材料复合培养3d后植入兔背部肌肉中，进行异位成骨观察。结果BMSCs在两种材料上能够良好地黏附和增殖，细胞活性及成骨性能不受材料影响，与对照组比较，差异无统计学意义（P〉0．05）；材料浸提液对细胞生长无毒性作用。异位成骨实验组随时间延长，新骨生成量增多；对照组则均无新骨形成。结论两种丝素蛋白／羟基磷灰石具有良好的细胞相容性，构建的组织工程化骨具有良好的异位成骨作用。

Objective To observe the cellular compatibility and the ectopic bone formation of silk fibroin/hydroxyapatite （SF/HA-1 and SF/HA-2 ）. Methods The rabbit＇ s bone marrow stromal cells （BMSCs）, after being induced to differentiate into osteoblasts, were transplanted into SF/HA- 1 and SF/ HA-2 and co-cultured for 3 to 5 days. BMSCs alone were cultured at the same condition to act as controls. The cellular morphology and function （ attachment, proliferation and differentiation） were assessed separately by the phase contrast microscopy, HE staining, SEM, MTT assay, and ALP activity. The material leaching liquor was used to test cell toxicity. The differentiated osteoblasts were seeded onto SF/HA with a density of 5×10^7/ml （SF/HA-1 ＋ BMSCs as groupl ;SF/HA-2 ＋ BMSCs as group 2 ）. The compounds with cells were co-cultured for 3 days and implanted into muscular pouch of back of rabbits, and SF/HA alone was implanted as a control group. The effectiveness of bone formation was assessed by means of gross observation and histology after implantation. Results BMSCs could adhere to SF/HA -1 and SF/HA-2, and proliferate and grow on the surface of the composites normally. The cellular activity and function were not affected by the materials, and no statistically significant difference was found among group 1, group 2 and control group （ P 〉 0.05 ）. Cell toxicity test indicated these materials had no toxic effect on BMSCs. New osteogenesis was detected at the end of the 4th ,8th and 12th week after implantation in groups 1 and 2,while there was no new bone formation in control group. Conclusion SF/HA has a good biocompati- bility and the tissue engineered bone of SF/HA has a good ability of ectopia osteogenesis in vivo.