Department of Structural and Geotechnical Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile, Vicuña Mackenna 4860, Santiago, Chile; Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Vicuña Mackenna 4860, Santiago, Chile.
Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Vicuña Mackenna 4860, Santiago, Chile.
Acta Biomater. 2024 Jun;181:282-296. doi: 10.1016/j.actbio.2024.04.039. Epub 2024 May 3.
Irreversible alveolar airspace enlargement is the main characteristic of pulmonary emphysema, which has been extensively studied using animal models. While the alterations in lung mechanics associated with these morphological changes have been documented in the literature, the study of the mechanical behavior of parenchymal tissue from emphysematous lungs has been poorly investigated. In this work, we characterize the mechanical and morphological properties of lung tissue in elastase-induced emphysema rat models under varying severity conditions. We analyze the non-linear tissue behavior using suitable hyperelastic constitutive models that enable to compare different non-linear responses in terms of hyperelastic material parameters. We further analyze the effect of the elastase dose on alveolar morphology and tissue material parameters and study their connection with respiratory-system mechanical parameters. Our results show that while the lung mechanical function is not significantly influenced by the elastase treatment, the tissue mechanical behavior and alveolar morphology are markedly affected by it. We further show a strong association between alveolar enlargement and tissue softening, not evidenced by respiratory-system compliance. Our findings highlight the importance of understanding tissue mechanics in emphysematous lungs, as changes in tissue properties could detect the early stages of emphysema remodeling. STATEMENT OF SIGNIFICANCE: Gas exchange is vital for life and strongly relies on the mechanical function of the lungs. Pulmonary emphysema is a prevalent respiratory disease where alveolar walls are damaged, causing alveolar enlargement that induces harmful changes in the mechanical response of the lungs. In this work, we study how the mechanical properties of lung tissue change during emphysema. Our results from animal models show that tissue properties are more sensitive to alveolar enlargement due to emphysema than other mechanical properties that describe the function of the whole respiratory system.
不可逆的肺泡空间扩大是肺气肿的主要特征，已经有大量的动物模型研究对此进行了广泛的研究。虽然文献中已经记录了与这些形态变化相关的肺力学改变，但对肺气肿肺实质组织的力学行为的研究还很少。在这项工作中，我们在不同严重程度的弹性蛋白酶诱导肺气肿大鼠模型中，对肺组织的力学和形态特性进行了特征描述。我们使用合适的超弹性本构模型来分析非线性组织行为，这些模型可以根据超弹性材料参数来比较不同的非线性响应。我们进一步分析了弹性蛋白酶剂量对肺泡形态和组织材料参数的影响，并研究了它们与呼吸系统力学参数的关系。我们的结果表明，尽管肺力学功能不受弹性蛋白酶处理的显著影响，但组织力学行为和肺泡形态受到显著影响。我们进一步表明，肺泡扩张与组织软化之间存在很强的相关性，这与呼吸系统顺应性无关。我们的研究结果强调了理解肺气肿肺组织力学的重要性，因为组织特性的变化可以检测到肺气肿重塑的早期阶段。
气体交换对生命至关重要，强烈依赖于肺部的机械功能。肺气肿是一种常见的呼吸系统疾病，肺泡壁受损，导致肺泡扩大，从而导致肺部机械响应产生有害变化。在这项工作中，我们研究了肺气肿过程中肺组织力学特性的变化。我们从动物模型中得到的结果表明，与描述整个呼吸系统功能的其他机械特性相比，由于肺气肿导致的组织特性对肺泡扩大更为敏感。
