钛铌锆β钛合金生物相容性的体外实验研究

An in vitro study of the biocompatibility of Ti-Nb-Zr Bate titanium alloy

[目的]通过体外实验对自行研发的低弹性模量、高强度新型β型钛合金人工关节假体材料生物相容性进行评价。[方法](1)采用L-929细胞(小鼠成纤维细胞)对合金进行细胞毒性试验,将细胞相对增殖率(RGR)转换成6级材料毒性进行评级。(2)将1μm左右的钛铌锆合金(Ti-Nb-Zr)颗粒与J774A.1巨噬细胞体外共同培养24～48h后,采用倒置相差显微镜和透射电镜观察细胞变化、RT-PCR方法测定IL-6和TNF-α表达、ELISA法测定细胞培养上清TNF-α等方法对Ti-Nb-Zr的生物相容性进行评价,并与传统的人工关节假体材料进行比较。[结果]Ti-Nb-Zr的细胞毒性为0级。吞噬了Ti-Nb-Zr颗粒的J774A.1巨噬细胞形态改变明显轻于钴铬钼颗粒组和钛铝钒颗粒组。巨噬细胞与钛铝钒合金颗粒、钴铬钼合金颗粒和Ti-Nb-Zr颗粒共同培养48h后都有IL-6和TNF-αmRNA表达的增加,钴铬钼颗粒和钛铝钒颗粒引起增加更加明显。ELISA方法测定显示:巨噬细胞吞噬Ti-Nb-Zr颗粒48h后分泌TNF-α的量明显低于钛铝钒和钴铬钼(P<0.05)。[结论]低弹性模量Ti-Nb-Zr钛合金具有优良的体外组织相容性,是一种有前途的骨科内植物材料。

[Objective]To evaluate the biocompatibility of a new bate titanium alloys made of titanium, niobium and zirconium （Ti-Nb-Zr） which have higher strength and lower elastic modulus by in vitro study.[Method]（1）the cell toxicity of Ti-Nb-Zr was evaluated using L-929 cell line＇s relative growth rate （RGR） which was transformed into 6 toxicity ranks in according with the national standard,（2）the J774A.1macrophages cultured with Ti-Nb-Zr particles whose diameter was about 1 μm for 24-48 hours were observed using inverted phase contrast microscopy and transmission electron microscopy. Expression of IL-6 and TNF-α mRNA in these cells were measured using RT-PCR technique. The TNF-α in the supernatant was also measured using ELISA method. All the results were compared with the traditional orthopedic implants metal materials such as Ti-6Al-4V and Co-Gr-Mo.[Result]The cell toxicity of Ti-Nb-Zr was ranked zero degree. The particles could be seen in the macrophages under the light microscopy. Ti-Nb-Zr particles made the J774.A1 macrophages less configurative changes than Ti-6Al-4V and Co-Gr-Mo did.Expressions of IL-6 and TNF-α mRNA in J774.A1 cell were increased after stimulation for 48 hours by all kinds of metallic materials. The TNF-α in the supernatants of Ti-Nb-Zr group were less than that of the Ti-6Al-4V and Co-Gr-Mo groups （P〈0.05）.[Conclusion]The Ti-Nb-Zr beta titanium alloys developed in the author＇s lab have lower modulus and good biocompatibility. It is a promising material for orthopedic implants.