School of Materials Science and Engineering, Kookmin University, Seoul, 136-702, Republic of Korea.
Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA.
J Mech Behav Biomed Mater. 2019 Oct;98:213-224. doi: 10.1016/j.jmbbm.2019.06.022. Epub 2019 Jun 21.
This study investigates the morphology, microstructure, compressive behavior, biocorrosion properties, and cytocompatibility of magnesium (Mg)-aluminum (Al) alloy (AE42) scaffolds for their potential use in biodegradable biomedical applications. Mg alloy scaffolds were successfully synthesized via a camphene-based freeze-casting process with precisely controlled heat treatment. The average porosity was approximately 52% and the median pore diameter was ∼13 μm. Salient deformation mechanisms were identified using acoustic emission (AE) signals and adaptive sequential k-means (ASK) analysis. Twinning, dislocation slip, strut bending, and collapse were dominant during compressive deformation. Nonetheless, the overall compressive behavior and deformation mechanisms were similar to those of bulk Mg based on ASK analysis. The corrosion potential of the Mg alloy scaffold (-1.44 V) was slightly higher than that of bulk AE42 (-1.60 V), but the corrosion rate of the Mg alloy scaffold was faster than that of bulk AE42 due to the enhanced surface area of the Mg alloy scaffold. As a result of cytocompatibility evaluation following ISO10993-5, the concentration of the Mg alloy scaffold extract reducing cell growth rate to 50% (IC) was 10.7%, which is higher (less toxic) than 5%, suggesting no severe inflammation by implantation into muscle.
本研究调查了镁-铝（AE42）合金支架的形态、微观结构、压缩性能、生物腐蚀性和细胞相容性，以评估其在可生物降解的生物医学应用中的潜力。通过以莰烯为基础的冷冻铸造工艺，并进行精确控制的热处理，成功合成了镁合金支架。平均孔隙率约为 52%，中值孔径约为 13μm。利用声发射（AE）信号和自适应序贯 k-均值（ASK）分析，确定了明显的变形机制。孪生、位错滑移、支柱弯曲和崩塌是压缩变形的主要机制。尽管如此，基于 ASK 分析，整体压缩性能和变形机制与块状 Mg 相似。镁合金支架的腐蚀电位（-1.44V）略高于块状 AE42 的腐蚀电位（-1.60V），但由于镁合金支架的表面积增大，其腐蚀速率较快。根据 ISO10993-5 的细胞相容性评估，镁合金支架浸提液将细胞生长率降低至 50%（IC）的浓度为 10.7%，这比 5%更高（毒性更低），表明植入肌肉后没有严重的炎症反应。
