对遭受低氧的豚鼠主动脉的机械损伤和粘弹性进行表征。

Characterization of mechanical damage and viscoelasticity on aortas from guinea pigs subjected to hypoxia.

作者信息

Bezmalinovic Alejandro, Navarrete Álvaro, Latorre Marcos, Celentano Diego, Herrera Emilio A, García-Herrera Claudio

机构信息

Biomechanics and Biomaterials Laboratory, Department of Mechanical Engineering, Universidad de Santiago de Chile, Santiago, Chile.

Center for Research and Innovation in Bioengineering, Universitat Politècnica de València, Valencia, Spain.

出版信息

Sci Rep. 2025 Apr 18;15(1):13447. doi: 10.1038/s41598-025-96086-4.

Abstract

To reliably assess the rupture risk of the aorta, along with the hazardousness of cardiovascular diseases and other extreme conditions or the effect of possible treatments, it is necessary to understand the influence of damage mechanisms along with the frequency and rate of mechanical loads. In particular, hypobaric hypoxia, an oxygen deficiency in the organism due to its low atmospheric partial pressure, is reported to alter the mechanical properties of blood vessels. In this work, we characterized the passive mechanical response of the aorta, seeking to capture the influence of hypoxia on their elastic, damage, and viscoelastic properties under ex-vivo conditions. The mechanical behavior of the aortic wall is described using an anisotropic hyperelastic model including two fiber families with asymmetric dispersion, along with an anisotropic damage model and an orthotropic viscoelastic model based on a reverse multiplicative decomposition of the deformation gradient. The constitutive model was experimentally calibrated from uniaxial-relaxation and biaxial-tensile test results, previously performed on thoracic aorta samples of guinea pigs. A group of guinea pigs subjected to hypoxia was contrasted with a normoxic (control) group. Cyclic-load stages of uniaxial tests were used to assess dissipation. Once the constitutive model was implemented and calibrated, its performance was evaluated via the numerical simulation of a bulge pressurization test to estimate energy dissipation and pressure associated with the onset of damage. Results indicated that hypoxia does not alter the visco-hyperelastic or damage behavior of the aorta. Besides, the pressure delivered by bulge-test simulations at the onset of damage on collagen fibers was representative of an arterial hypertensive condition.

摘要

为了可靠地评估主动脉的破裂风险,以及心血管疾病和其他极端情况的危险性或可能治疗的效果,有必要了解损伤机制的影响以及机械负荷的频率和速率。特别是,低氧性缺氧,即由于大气分压低导致机体缺氧,据报道会改变血管的力学性能。在这项工作中,我们对主动脉的被动力学响应进行了表征,试图捕捉缺氧对其在离体条件下的弹性、损伤和粘弹性特性的影响。使用包含两个具有不对称分布的纤维族的各向异性超弹性模型,以及基于变形梯度反向乘法分解的各向异性损伤模型和正交各向异性粘弹性模型来描述主动脉壁的力学行为。本构模型是根据先前对豚鼠胸主动脉样本进行的单轴松弛和双轴拉伸试验结果进行实验校准的。将一组经历缺氧的豚鼠与常氧(对照)组进行对比。单轴试验的循环加载阶段用于评估耗散。一旦本构模型得以实施和校准,便通过鼓泡加压试验的数值模拟来评估其性能,以估计与损伤起始相关的能量耗散和压力。结果表明,缺氧不会改变主动脉的粘弹性超弹性或损伤行为。此外,鼓泡试验模拟在胶原纤维损伤起始时所施加的压力代表了动脉高血压状态。

https://cdn.ncbi.nlm.nih.gov/pmc/blobs/b593/12008416/5010dfeed6f0/41598_2025_96086_Fig1_HTML.jpg

文献AI研究员

20分钟写一篇综述,助力文献阅读效率提升50倍

立即体验

用中文搜PubMed

大模型驱动的PubMed中文搜索引擎

马上搜索