Ti-25Nb-3Mo-3Zr-2Sn合金表面晶粒细化对成骨细胞行为的影响

Effect of surface grain refinement of Ti-25Nb-3Mo-3Zr-2Sn alloy on the regulation of osteoblast behavior

目的研究Ti-25Nb-3Mo-3Zr-2Sn(TLM)合金表面晶粒细化对HFOB1.19成骨细胞生物学行为的影响。方法实验分为两组,实验组(SMATed组)采用表面机械研磨处理(SMAT)方法在TLM合金表面制备一层β-Ti的纳米结构层,对照组(unSMATed组)采用未经SMAT的钛合金,将两组钛合金样品机械抛光至镜面。原子力显微镜分析两组样品表面的粗糙度及拓扑结构,光学显微镜及透射电镜分析表层晶粒大小,扫描电镜及MTT法分别考察成骨细胞的形态及细胞活力,并采用Real-time PCR技术分析材料对骨涎蛋白(BSP)及骨粘连蛋白(ON)基因表达的影响。结果抛光处理后的unSMATed组和SMATed组钛合金样品表面具有相近的微观粗糙度及拓扑结构,最表层的晶粒尺度分别为90±20μm及30±7nm。成骨细胞与两组样品直接接触培养1、5、24、72、168h,SMATed组样品表面细胞活性在各时间点均明显高于UnSMATed组(P<0.05);成骨细胞在两组样品表面培养3、7、14d后,SMATed组样品表面BSP及ON的表达水平在各时相点均显著高于unSMATed组(P<0.05)。结论 TLM合金表面晶粒细化能显著促进成骨细胞的黏附、增殖及胞内特异性蛋白基因的表达,改善合金生物相容性。

Objective To investigate the effect of surface grain refinement of Ti-25Nb-3Mo-3Zr-2Sn （TLM） alloy on the regulation of HFOB1.19 osteoblast behavior. Methods The experiment was designed as two groups：nanocrystalline layer with pure β-Ti was fabricated by surface mechanical attrition treatment （SMAT） on TLM alloy in experimental group （SMATed group）, and the alloy in control group were not be treated by SMAT＆nbsp;（unSMAT group）. Subsequently, the SMATed and unSMATed samples were mechanically polished to mirror finish. Surface roughness and topography of the samples in two groups were analyzed by atomic force microscope, grain sizes in the surface layer were observed by optical microscopy and transmission electron microscopy, obsteoblast morphology and viability were examined by scanning electron microscope and MTT method respectively, and gene expressions of bone sialoprotein （BSP） and osteonectin （ON） were evaluated by Real-time PCR. Results The samples in two groups showed similar surface roughness and topography, and the grain size in the exposed surface layers of unSMATed and SMATed samples was 90 ± 20 μm and 30 ± 7 nm, respectively. At 1, 5, 24, 72, 168 h after the direct culture of obsteoblast and the samples, cell viability on the surface of SMATed samples were better than that of unSMATed samples （P 〈0.05）; At 3, 7, 14 d after the culture of obsteoblast and the samples, BSP and ON gene expressions on the surface of SMATed samples were higher than those of unSMATed samples （P 〈0.05）. Conclusions For TLM alloy, surface grain refinement can significantly promote osteoblast adhesion, proliferation, intracellular specific protein-related gene expressions, and improve its cell biocompatibility.