Gu X N, Zheng W, Cheng Y, Zheng Y F
State Key Laboratory for Turbulence and Complex System and Department of Advanced Materials and Nanotechnology, College of Engineering, Peking University, Beijing 100871, China.
Acta Biomater. 2009 Sep;5(7):2790-9. doi: 10.1016/j.actbio.2009.01.048. Epub 2009 Feb 7.
To reduce the biocorrosion rate by surface modification, Mg-Ca alloy (1.4wt.% Ca content) was soaked in three alkaline solutions (Na(2)HPO(4), Na(2)CO(3) and NaHCO(3)) for 24h, respectively, and subsequently heat treated at 773K for 12h. Scanning electron microscopy and energy-dispersive spectroscopy results revealed that magnesium oxide layers with the thickness of about 13, 9 and 26microm were formed on the surfaces of Mg-Ca alloy after the above different alkaline heat treatments. Atomic force microscopy showed that the surfaces of Mg-Ca alloy samples became rough after three alkaline heat treatments. The in vitro corrosion tests in simulated body fluid indicated that the corrosion rates of Mg-Ca alloy were effectively decreased after alkaline heat treatments, with the following sequence: NaHCO(3) heated<Na(2)HPO(4) heated<Na(2)CO(3) heated. The cytotoxicity evaluation revealed that none of the alkaline heat treated Mg-Ca alloy samples induced toxicity to L-929 cells during 7days culture.
为通过表面改性降低生物腐蚀速率，将镁钙合金（钙含量为1.4wt.%）分别浸泡在三种碱性溶液（Na₂HPO₄、Na₂CO₃和NaHCO₃）中24小时，随后在773K下热处理12小时。扫描电子显微镜和能谱分析结果表明，经过上述不同的碱性热处理后，在镁钙合金表面形成了厚度约为13、9和26微米的氧化镁层。原子力显微镜显示，经过三次碱性热处理后，镁钙合金样品的表面变得粗糙。在模拟体液中的体外腐蚀试验表明，碱性热处理后镁钙合金的腐蚀速率有效降低，顺序如下：NaHCO₃加热处理＜Na₂HPO₄加热处理＜Na₂CO₃加热处理。细胞毒性评估显示，在7天的培养过程中，经碱性热处理的镁钙合金样品均未对L-929细胞产生毒性。
