生物镁合金植入动物体内的生物相容性研究

A study of the biocompatibility in vivo to implant the bio-magnesium alloys in rabbit

目的 观察镁合金在动物体内的生物相容性及其在体内的降解和新骨形成情况.方法 取32只中国种健康成年大白兔,随机分为两组:无羟基磷灰石(HA)涂层镁合金组(A组);有羟基磷灰石涂层镁合金组(B组).于动物左股骨髁部钻洞ψ3.5 mm×9 mm,分别将两组镁合金圆柱体(ψ 3.5 mm×9 mm)植入.于术前第1天,术后第8、12、16、24周检测静脉血、尿中镁离子浓度,天门冬氨酸氨基转移酶、白蛋白、尿素、肌酐水平.于术后第1、4、8、12、16、24周对植入材料部位拍摄X线片.取股骨髁部做Micro-CT分析,取心脏、肝脏、脾脏、肾脏和股骨髁部行病理分析.结果 两组材料血、尿中镁离子浓度波动不大,均在正常值范围.内脏组织病理结果均正常,各项生化指标变化差异无统计学意义.有涂层组周围新骨生成多且与材料结合紧密,镁合金棒降解较慢.结论 有涂层镁合金具有良好的生物相容性,在动物体内降解较慢,且周围有大量新骨形成.

Objective To investigate the biocompatibility degradation and bone formation in vivo to implant the bio-magnesium alloys in rabbit. Methods A total of 32 China rabbits were randomly divided into magnesium alloys without hydroxyapatite(HA) coatings group( group A) and magnesium alloys with hydroxyapatite (HA) coatings group ( group B ). The left condyles of femur were drilled ( ψ 3.5 mm ×9 mm)and separately implanted with different magnesium alloys. The concentrations of magnesiumionion in blood and urine, the levels of serum glutamic-oxalacetic transaminase, albumin, urea nitrogen and urine creatinine were measured at 1 day pre-operatively ,8,12,16 and 24 weeks post- operatively. The magnesium alloys samples were photographed by X -ray at 1,4,8,12,16 and 24 weeks post -implantations,and then condyles of femur were obtained and analyzed using Micro -CT, tissues of heart, liver, spleen,kidney and condyles of femur were used for pathological analysis. Results There were no significant variations in the concentrations of magnesium ion in blood and urine, and the concentrations were in normal range. The pathology of all the organs were normal, and there were no significant difference of biochemical indicator between the two groups. There were no significant abnormalities in the pathological analysis of heart,liver, spleen or kidney in the two groups. New bones in group A were more and had tighter binding with the magnesium alloys, compared with group B. In addition, the magnesium alloys in group A had a slower degradation rate. Conclusions HA -coated magnesium alloys which have good biocompatibility can slow down the degradation rate and stimulate the formation of new bone tissue.