飞秒激光在钛合金表面改性中的应用及其对成骨细胞黏附和增殖的影响

Application of femto-second laser in titanium alloy surface modification and its influence in adhesion and proliferation of osteoblasts

目的:采用不同能量密度飞秒激光处理钛合金表面,比较其对成骨细胞黏附和增殖的影响,探讨飞秒激光在种植材料表面改性中的作用。方法:钛合金Ti-6Al-4V圆片进行打磨抛光并采用不同能量密度的飞秒激光处理,分为低能量组(0.07J.cm-2)和高能量组(1.40J.cm-2),同时以单纯打磨抛光样本为对照组,扫描电镜观察各组材料表面形貌;人成骨样细胞素MG63与各组材料进行共培养,扫描电镜观察材料表面黏附细胞的形态并采用丫啶橙染色和荧光显微镜观察黏附细胞的数量,用噻唑蓝(MTT)比色分析法测定MG63细胞的吸光度(A)值,分析不同时间点细胞增殖率。结果:飞秒激光处理钛合金表面形成2种不同的微形貌结构,即纳米级平行排列的条纹状结构和微米级的凸起与纳米级的条纹相结合的微纳复合结构;24h各组黏附的细胞数量相近;48h各组材料表面单个细胞形态均不明显,但微纳复合结构表面细胞覆盖面积大于纳米条纹表面和对照组的光滑表面,高能量组细胞增殖率明显高于对照组和低能量组(P<0.05)。结论:飞秒激光处理钛合金表面产生的微纳复合结构有利于MG-63成骨细胞黏附和增殖。

Objective To treat the titanium alloy serface with femto-second lasers with different energy densities,and compare their influence in adhesion and proliferation of osteoblasts,and to discuss the effect of femto-second laser on the implant material surface modification.Methods Disk-like Ti-6Al-4V titanium alloy was polished and processed by femto-second lasers with different energy densities and then divided into low-energy group（0.07 J·cm-2） and high-energy group（1.40 J·cm-2）,and the untreated disk-like Ti-6Al-4V titanium alloy was regarded as control group;the morphology of the material surface in each group was observed by scanning electron microscope.The human osteoblast-like cell line MG63 were co-cultured with different materials,the morphology of the adherent cells in each group was observed by scanning electron microscope,and the quantity of the adherent cells on the surface was detected by acridine orange staining and fluorescence microscope,and the optical density（A） value of MG63 cells was determined by methylthiazolyldiphenyl-tetrazolium bromide（MTT） colorimetric analysis,and the cell proliferation rates at different time were analyzed.Results Two kinds of micro-morphology structure were formed on the titanium alloy surface modified by femto-second laser,one of which was nanoscaled paralleled stripe structure and the other was micro-nano composite structure of micron-sized protrudes combined with the nanoscaled stripes structure.The amounts of the adheren cells in different groups were close at 24 h.After 48 h,the morphology of single cell on material surface in each group was not obvious,however,the cell cover area of micro-nano composite structure surface was bigger than those of nanoscaled composite structure surface and the smooth surface in control group.The cell proliferation rate in high-energy group was higher than those in low-energy group and control group（P0.05）.Conclusion The micro-nano composite structure on the titanium alloy surface induced by femto-second laser can promote the adhesion and proliferation of MG63 osteoblasts.