纳米级二氧化锆增韧羟基磷灰石生物复合陶瓷对兔骨髓基质干细胞增殖、分化的影响

背景:课题组拟对纳米级二氧化锆增韧的羟基磷灰石生物陶瓷进行一些初步研究,主要集中在生物力学匹配性,化学稳定性,以及生物相容性实验,其中体外细胞培养实验具有可控性,可重复性,能很好地反映材料的生物相容性。目的:比较纳米级二氧化锆增韧的羟基磷灰石、纯羟基磷灰石两种材料对兔骨髓基质干细胞增殖、分化的影响。方法:将骨髓基质干细胞置于含体积分数为20%胎牛血清的DMEM培养基中培养,传代后改用含β-甘油磷酸钠,地塞米松和维生素C的条件培养基培养。取传至第3代的成骨细胞,以1.0×108L-1浓度接种于放有材料块的细胞培养板中,培养第1~10天倒置相差显微镜观察细胞生长情况,绘制细胞生长曲线,并进行碱性磷酸酶活性检测。培养第6天的细胞和材料复合物用多聚甲醛固定进行扫描电镜观察。结果与结论:MTT法测得两种材料培养的细胞生长曲线无显著差异。复合培养的兔骨髓基质干细胞能够保持正常分泌碱性磷酸酶的功能。电镜照片也同样证实了两种材料表面均有细胞的附着。说明纳米级二氧化锆增韧的羟基磷灰石、纯羟基磷灰石均不影响成骨细胞增长分化,具有优良的成骨细胞相容性。

Effects of nano-zirconium dioxide-toughened hydroxyapatite bioceramics on proliferation and differentiation of rabbit bone marrow stromal cells

BACKGROUND: Research group has performed some preliminary studies pertaining to zirconia toughened nano-hydroxyapatite (HA-ZrO2) bioceramics, mainly in the biomechanical compatibility, chemical stability, and biocompatibility. Among them, in vitro cell culture experiments are controllable and repeatable, can well reflect the material’s biocompatibility. OBJECTIVE: To study the influence to the growth and differentiation of rabbit bone marrow stromal stem cells by HA-ZrO2 or HA materials. METHODS: The rabbit bone marrow stromal stem cells were cultured in beccos modified eagle’s medium (DMEM) containing 20% fetal bovine serum, the subsequent cell passage was cultured in conditioned medium containing dexamethasone, beta-sodium glycerophosphate and ascorbic acid. The third passage osteoblasts were cultured in cell culture plate with materials at 1.0×108/L. The proliferation of all the cultured cells were observed at 1-10 days under inverted phase contrast microscope and the curve of cell-growth was plotted. The activity of alkaline phosphatase was detected. At 6 days of the culture, cells and composite materials were fixed with paraformaldehyde and observed under scanning electron microscope. RESULTS AND CONCLUSION: MTT assay showed the growth curve of cells cultured in two materials had no significant difference. The combined culture of rabbit bone marrow stromal cells can maintain normal function of secreting alkaline phosphatase. Electron microscopy photographs also confirmed the cell adhesion on two kinds of materials. HA-ZrO2 and HA show no adverse effect on the growth and differentiation of osteoblasts, with excellent compatibility.