Biomimetic porous Mg with tunable mechanical properties and biodegradation rates for bone regeneration
Biomimetic porous Mg with tunable mechanical properties and biodegradation rates for bone regeneration
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DOI：
10.1016/j.actbio.2018.11.045
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发表时间：
2019-01-15
影响因子：
9.7
通讯作者：
Jung, Hyun-Do
中科院分区：
文献类型：
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作者：
Kang, Min-Ho;Lee, Hyun;Jung, Hyun-Do
镁多孔支架的腐蚀速度快，大大降低了支架的机械强度，限制了其在医学上的应用。模拟骨的结构和成分可以改善多孔镁支架的力学和生物性能。还可以通过水相沉淀法在镁结构表面涂覆透明质酸，以提高其耐蚀性和生物相容性。然而，由于羟基磷灰石涂层的脆性，容易在涂层中产生裂纹，这可能会影响支架的腐蚀和生物功能。因此，在本研究中，将聚醚酰亚胺(PEI)-SiO_2杂化膜应用于HA包覆的仿生多孔镁，以获得与PEI相关的高耐蚀性和与SiO_2具有良好生物活性的结构。通过空间保持器法调节制备过程中使用的氯化钠(NaCl2)颗粒的浓度来控制镁的孔隙率。力学性能测试表明，随着致密区比例的增加，仿生多孔镁的抗压强度和硬度也随之增加。另外，研究结果表明，HA/(PEI-SiO_2)杂化涂层仿生镁是一种很有前途的可生物降解骨科支架材料。体外测试表明，与HA和HA/PEI涂层支架相比，所提出的混合涂层降低了降解率并促进了成骨细胞的扩散。此外，在体兔股骨距骨沟模型的测试表明，改善了组织形成，减少了腐蚀和降解，改善了支架上的骨形成。然而，由于其较差的机械性能和对快速腐蚀的敏感性，将多孔镁应用于骨科生物材料是有局限性的。在这里，我们对多孔镁的结构和包覆层进行了战略性设计，以克服这些限制。首先，通过模仿致密和多孔区相结合的骨结构来制备多孔镁，从而提高了力学性能。此外，还在仿生多孔镁表面涂覆了HA/(PEI-SiO_2)杂化层，以提高其耐腐蚀性和生物相容性。最终的结果是，HA/(PEI-SiO_2)包覆的仿生多孔镁具有可调的力学和生物可降解性，有望成为承载骨科应用的候选材料。(C)2018 Acta Materialia Inc.由Elsevier Ltd.出版。保留所有权利。
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 SignificancePorous 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. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.