羟基磷灰石涂层镁合金材料体内降解及生物相容性研究

The degradation and biocompatibility of Hydroxyapatite coatingmagnesium alloy materials in rabbits＇ condyles of femur

目的 在家兔股骨髁上植入带羟基磷灰石（HAP）涂层的镁合金材料,观察该材料在家兔体内的降解、骨传导作用、骨诱导作用及其生物相容性.方法 将33只家兔分为3组,分别为对照组、无涂层材料组和带涂层材料组,于术后不同时期通过血清学测试观察家兔体内血清镁浓度的变化,观察材料在体内不良反应情况;通过放射学观察材料植入后的降解和新骨生长;通过组织病理学观察植入此材料后,周围组织和骨骼的变化,观察其降解的时间、过程等;通过不同降解速率的材料植入后的生物学观察,揭示该材料在体内的降解途径、代谢方式以及降解产物在体内的滞留情况,从而获得与骨组织正常生长相适配的降解速率,并评价该材料的生物相容性.结果 该材料植入后无血清镁含量的增高,材料降解产生的镁离子能够正常代谢,与对照组比较差异无统计学意义（P＞0.05）,具备较好的生物相容性.放射学检查示HAP涂层镁合金材料在体内的降解速度缓慢,材料周围有新骨生成.未表面改性的材料在体内降解速度快,材料周围骨组织紊乱,可能有炎症反应发生.通过组织病理学观察,HAP涂层的试样周围有肉芽组织和新生骨小梁生成,未发现严重的肉芽肿胀和炎症反应;而无涂层的试样周围也有肉芽组织和骨小梁生成,但有较明显的肉芽肿胀和淋巴细胞反应.结论 HAP涂层镁合金材料不会造成血清中镁含量增高,可有效控制镁合金植入初期的降解速率,且具备良好的骨传导和骨诱导作用,加速骨组织的愈合.

Objective To investigate the degradation, osteoacusis, induction and biocompatibility of the Hydroxyapatite （ HAP） coating magnesium alloy by implant them in rabbits＇ comdyles of femur. Methods 33 rabbits were devided into 3 groups： they were implanted in material without coating and material with coating respectively, and didin＇ t implant anything as control group. Observing the variation of serum magnesium through serology test to study the side effect of these materials. Observing degradation and newly formed bone through radiology observation; to study the time and process of degradation and the variation of surounding tissue and skeletal through histopathology test, to evaluate the biocompatibility of these materials through biology observation. Results The serum magnesium didn＇ t rise after implanting these materials, there were no significant difference compared with contral group （P 〉 0.05）. The radiology result showed that materials with HAP coating degraded slowly and there were new bone formed surroud-ing it while the marerials without HAP coating degraded quickly and maby there were inflammation surround it because of the irregular osseous tissue. The histopathology result showed that there were granulation tissue and new bone trabecula formed surrounding the HAP coating materials and no severe granulation swelling and inflammatory reaction found; there were obvious granulation swelling and lymphocyte reaction exist accompanied with granulation tissue and new bone trabecula. Conclusion HAP coating magnesium alloy wouldn＇ t rise the magnesium in serum; the degrade velocity was variated effectively by coating with HAP; It also can accelerate the heal of osseous tissue because of its osteoacusis and entrainment.