多尺度理论模型表明,与衰老相关的皮质骨的机械降解除了孔隙性之外,还是由微观结构变化驱动的
André Gutiérrez Marty1, Paul E Barbone1, Elise F Morgan2
1Mechanical Engineering, Boston University, 110 Cummington Mall, Boston, 02115, MA, USA; Center for Multiscale and Translational Mechanobiology, Boston University, 110 Cummington Mall, Boston, 02115, MA, USA.
概括
老化的骨头由于微观结构的变化而失去力量,而不仅仅是毛孔性. 老年人骨头早些时候会出现纤维破裂,这会显著影响整体机械性能.
科学领域:
- 生物力学 生物力学
- 材料科学 材料科学 材料科学
- 老年学是指老年学的学科.
背景情况:
- 衰老显著改变皮层骨微观结构.
- 这些微观结构变化在宏观层面上产生了深刻的机械后果.
- 了解这些关系对于解决与年龄相关的骨脆弱性至关重要.
研究的目的:
- 机械地了解皮质骨中的与衰老相关的微观结构变化如何影响其宏观机械性质.
- 模拟皮质骨作为纤维束,并模拟其机械行为的衰老影响.
- 为了确定关键的微观结构参数,有助于与年龄相关的骨质退化.
主要方法:
- 皮质骨模拟为一个平行,弹性-塑料纤维捆,代表骨和间歇组织.
- 通过增加多孔性,改变骨与间隙纤维的比率,以及修改纤维材料特性来模拟衰老.
- 成熟的 (20-60岁) 的比较分析. 和老年人 (60+) 骨模型,包括孤立的参数变化.
主要成果:
- 所有三个模拟的衰老参数 (多孔度,纤维比率,材料特性) 都是复制文献报告的骨机械性质下降所必需的.
- 在成熟骨和老年骨中,间歇性纤维破裂是最终负载后开始的,在老年骨中更早开始和完成.
- 骨的可塑性和逐渐破裂有助于在间歇性纤维故障后剩余的机械反应.
结论:
- 超出毛孔性的微观结构变化,包括骨面积分数和组织材料特性,对于理解与年龄相关的骨机械衰退至关重要.
- 老年人骨头早些时候表现出间歇性纤维的衰竭,导致强度和性降低.
- 这种建模方法突出了骨衰老中微观结构因素的复杂相互作用.
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