氟涂层对AZ31B镁合金植入初期降解作用的影响

Experimental study of fluoride coating on the degradation of magnesium alloy AZ31B in vitro

目的观察氟涂层对AZ31B镁合金植入初期降解速度的影响。方法分别将无涂层(对照组)和氟涂层(观察组)的AZ31B镁合金浸泡于骨细胞培养基DMEM溶液(模拟体液),分别于浸泡1、3、5、7、14 d时后观察两组模拟体液pH值,扫描电镜下观察两组浸泡前和浸泡7 d时AZ31B镁合金材料表面形貌。结果对照组镁合金浸泡1、3、5、7、14 d模拟体液pH值分别为7.51±0.15、8.32±0.10、9.36±0.10、9.79±0.09、9.87±0.09,呈升高趋势,观察组分别为7.29±0.07、7.44±0.06、7.47±0.11、7.65±0.11、7.74±0.08,各时点pH值相比,P均>0.05。对照组浸泡前镁合金表面相对光滑,观察组镁合金表面致密、光滑,有一些同向的纹理;浸泡7 d后,无涂层AZ31B镁合金表面呈龟裂状;氟涂层AZ31B镁合金表面无明显改变,可见散在腐蚀凹陷。结论氟涂层可以在一定程度上抑制AZ31B镁合金植入初期的降解作用。

Objective To study the viability of using magnesium alloy AZ31B coated with fluoride as biodegradable bone scaffolds materials.Methods Pieces of magnesium alloy AZ31B uncoated and coated with fluoride were immersed in DMEM culture medium respectively.The changes of the DMEM culture medium＇s pH valules and morphology of magnesium alloy AZ31B uncoated or coated were evaluated after immersion.Results The pH values of DMEM solution immersed by magnesium alloy AZ31B uncoated after 1,3,5,7,14 d were 7.51±0.15,8.32±0.10,9.36±0.10,9.79±0.09,9.87±0.09,while that immersed by magnesium alloy AZ31B coated with flouride were 7.29±0.07,7.44±0.06,7.47±0.11,7.65±0.11,7.74±0.08（all P0.05）.Before immersed,the surface of magnesium alloy AZ31B was smooth,while magnesium alloy AZ31B coated with fluoride was density and smooth texture.After immersed for 7 d,the surface of magnesium alloy AZ31B uncoated was corroded severely and the surface of magnesium alloy AZ31B coated with fluoride changed a little and appeared some pits.Conclusion Coated with fluoride can control the biodegradation rate of magnesium alloy AZ31B in some extent.