In vitro and in vivo degradation and mechanical properties of ZEK100 magnesium alloy coated with alginate, chitosan and mechano-growth factor

The biocompatibility, ultimate loading capacity and biodegradability of magnesium alloy make it an ideal candidate in biomedical fields. Fabrications of multilayered coatings carrying sodium alginate (ALG), chitosan (CHI) and mechano-growth factor (MGF) on fluoride-pretreated ZEK100 magnesium alloy have been obtained via layer by layer (LBL) to reduce the degradation rate of magnesium alloy in this study. The modified surfaces of ZEK100 substrates were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared (FTIR) and CARE EUT-1020 tester. Results reveal that multilayer-coated magnesium alloy can be successfully obtained with smooth surface morphology, and the mechanical properties of coated samples are almost the same as those of uncoated samples. However, the, fatigue life of coated ZEK100 is slightly larger than that of uncoated samples after 1 day of immersion. By comparing the degradation of uncoated and multilayer-coated ZEK100 samples in vitro and in vivo, respectively, it is found that the degradation rate of ZEK100 samples can be inhibited by LBL modification on the surface of the sample; and the corrosion rate in vivo is lower than that in vitro, which help solve the rapid degradation problem of magnesium alloy. In terms of the visible symptom of tissues in the left femur medullary cavity and material responses on the surface, multilayer-coated ZEK100 magnesium alloy has a good biocompatibility. These results indicate that multilayer-coated ZEK100 may be a promising material for bone tissue repair. (C) 2016 Elsevier B.V. All rights reserved.

镁合金的生物相容性、极限承载能力和生物可降解性使其成为生物医学领域的理想候选材料。在本研究中，通过层层自组装（LBL）方法在经过氟化物预处理的ZEK100镁合金上制备了负载海藻酸钠（ALG）、壳聚糖（CHI）和力生长因子（MGF）的多层涂层，以降低镁合金的降解速率。利用扫描电子显微镜（SEM）、原子力显微镜（AFM）、傅里叶变换红外光谱（FTIR）和CARE EUT - 1020测试仪对ZEK100基体的改性表面进行了表征。结果表明，可以成功获得具有光滑表面形貌的多层涂层镁合金，且涂层样品的力学性能与未涂层样品几乎相同。然而，浸泡1天后，涂层ZEK100的疲劳寿命略大于未涂层样品。通过分别比较未涂层和多层涂层的ZEK100样品在体外和体内的降解情况，发现通过对样品表面进行LBL改性可以抑制ZEK100样品的降解速率；且体内的腐蚀速率低于体外，这有助于解决镁合金快速降解的问题。从左股骨髓腔内组织的可见症状以及表面的材料反应来看，多层涂层的ZEK100镁合金具有良好的生物相容性。这些结果表明，多层涂层的ZEK100可能是一种有前途的骨组织修复材料。（C）2016爱思唯尔B.V.版权所有。