The medical applications of porous Mg scaffolds are limited owing to its rapid corrosion, which dramatically decreases the mechanical strength of the scaffold. Mimicking the bone structure and composition can improve the mechanical and biological properties of porous Mg scaffolds. The Mg structure can also be coated with HA by an aqueous precipitation coating method to enhance both the corrosion resistance and the biocompatibility. However, due to the brittleness of HA coating layer, cracks tend to form in the HA coating layer, which may influence the corrosion and biological functionality of the scaffold. Consequently, in this study, hybrid poly(ether imide) (PEI)-SiO2 layers were applied to the HA-coated biomimetic porous Mg to impart the structure with the high corrosion resistance associated with PEI and excellent bioactivity with SiO2. The porosity of the Mg was controlled by adjusting the concentration of the sodium chloride (NaCl) particles used in the fabrication via the space-holder method. The mechanical measurements showed that the compressive strength and stiffness of the biomimetic porous Mg increased as the portion of the dense region increased. In addition, following results show that HA/(PEI-SiO2) hybrid-coated biomimetic Mg is a promising biodegradable scaffold for orthopedic applications. In-vitro testing revealed that the proposed hybrid coating reduced the degradation rate and facilitated osteoblast spreading compared to HA- and HA/PEI-coating scaffolds. Moreover, in-vivo testing with a rabbit femoropatellar groove model showed improved tissue formation, reduced corrosion and degradation, and improved bone formation on the scaffold. STATEMENT OF SIGNIFICANCE: Porous Mg is a promising biodegradable scaffold for orthopedic applications. However, there are limitations in applying porous Mg for an orthopedic biomaterial due to its poor mechanical properties and susceptibility to rapid corrosion. Here, we strategically designed the structure and coating layer of porous Mg to overcome these limitations. First, porous Mg was fabricated by mimicking the bone structure which has a combined structure of dense and porous regions, thus resulting in an enhancement of mechanical properties. Furthermore, the biomimetic porous Mg was coated with HA/(PEI-SiO2) hybrid layer to improve both corrosion resistance and biocompatibility. As the final outcome, with tunable mechanical and biodegradable properties, HA/(PEI-SiO2)-coated biomimetic porous Mg could be a promising candidate material for load-bearing orthopedic applications.

中文翻译：

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具有可调节的机械性能和生物降解速率的仿生多孔镁，可用于骨骼再生。

多孔镁支架的医学应用由于其快速腐蚀而受到限制，这会大大降低支架的机械强度。模仿骨骼的结构和成分可以改善多孔镁支架的机械和生物学特性。Mg结构还可以通过水沉淀涂覆法用HA涂覆，以增强耐腐蚀性和生物相容性。然而，由于HA涂层的脆性，在HA涂层中易于形成裂纹，这可能影响支架的腐蚀和生物学功能。因此，在这项研究中，将杂化聚醚酰亚胺（PEI）-SiO2层应用于HA涂层的仿生多孔Mg，以赋予该结构与PEI相关的高耐腐蚀性和与SiO2的优异生物活性。Mg的孔隙率是通过空间保持器方法调节制造中使用的氯化钠（NaCl）颗粒的浓度来控制的。力学测量表明，仿生多孔镁的压缩强度和刚度随着致密区域的增加而增加。此外，以下结果表明，HA /（PEI-SiO2）杂化仿生Mg是用于骨科应用的有前途的可生物降解支架。体外测试显示，与HA和HA / PEI涂层支架相比，拟议的混合涂层降低了降解速率并促进了成骨细胞的扩散。此外，使用兔股骨groove沟模型进行的体内试验显示，组织形成得到改善，腐蚀和降解减少，支架上的骨形成得到改善。重要性声明：多孔镁是用于骨科应用的有前途的可生物降解的支架。然而，由于多孔镁的机械性能差且易受快速腐蚀的影响，因此在骨科生物材料中使用多孔镁存在局限性。在这里，我们从战略上设计了多孔镁的结构和涂层，以克服这些限制。首先，通过模仿具有致密和多孔区域的组合结构的骨骼结构来制造多孔镁，从而提高了机械性能。此外，用HA /（PEI-SiO2）杂化层涂覆仿生多孔镁，以提高耐腐蚀性和生物相容性。作为最终结果，具有可调的机械和生物降解特性，