Characterisation of the mechanical properties of infarcted myocardium in the rat under biaxial tension and uniaxial compression.

Autor: Sirry MS; Division of Biomedical Engineering, Department of Human Biology, University of Cape Town, Observatory 7925, South Africa; Department of Biomedical Engineering, University of Medical Sciences and Technology, P.O. Box 12810, Khartoum, Sudan., Butler JR; Department of Clinical Sciences, College of Veterinary Medicine, Mississippi State University, MS 39762, USA., Patnaik SS; Tissue Bioengineering Laboratory, Department of Agricultural and Biological Engineering, Mississippi State University, MS 39762, USA., Brazile B; Tissue Bioengineering Laboratory, Department of Agricultural and Biological Engineering, Mississippi State University, MS 39762, USA., Bertucci R; Tissue Bioengineering Laboratory, Department of Agricultural and Biological Engineering, Mississippi State University, MS 39762, USA., Claude A; Department of Clinical Sciences, College of Veterinary Medicine, Mississippi State University, MS 39762, USA., McLaughlin R; Department of Clinical Sciences, College of Veterinary Medicine, Mississippi State University, MS 39762, USA., Davies NH; Cardiovascular Research Unit, Chris Barnard Division of Cardiothoracic Surgery, University of Cape Town, Observatory 7925, South Africa., Liao J; Tissue Bioengineering Laboratory, Department of Agricultural and Biological Engineering, Mississippi State University, MS 39762, USA., Franz T; Division of Biomedical Engineering, Department of Human Biology, University of Cape Town, Observatory 7925, South Africa; Centre for High Performance Computing, Rosebank 7700, South Africa; Bioengineering Science Research Group, Engineering Sciences, Faculty of Engineering and the Environment, University of Southampton, Southampton SO171BJ, UK. Electronic address: thomas.franz@uct.ac.za.
Jazyk: angličtina
Zdroj: Journal of the mechanical behavior of biomedical materials [J Mech Behav Biomed Mater] 2016 Oct; Vol. 63, pp. 252-264. Date of Electronic Publication: 2016 Jul 05.
DOI: 10.1016/j.jmbbm.2016.06.029
Abstrakt: Understanding the passive mechanical properties of infarcted tissue at different healing stages is essential to explore the emerging biomaterial injection-based therapy for myocardial infarction (MI). Although rats have been widely used as animal models in such investigations, the data in literature that quantify the passive mechanical properties of rat heart infarcts is very limited. MI was induced in rats and hearts were harvested immediately (0 day), 7, 14 and 28 days after infarction onset. Left ventricle anterioapical samples were cut and underwent equibiaxial and non equibiaxial tension followed by uniaxial compression mechanical tests. Histological analysis was conducted to confirm MI and to quantify the size of the induced infarcts. Infarcts maintained anisotropy and the nonlinear biaxial and compressive mechanical behaviour throughout the healing phases with the circumferential direction being stiffer than the longitudinal direction. Mechanical coupling was observed between the two axes in all infarct groups. The 0, 7, 14 and 28 days infarcts showed 438, 693, 1048 and 1218kPa circumferential tensile moduli. The 28 day infarct group showed a significantly higher compressive modulus compared to the other infarct groups (p=0.0060, 0.0293, and 0.0268 for 0, 7 and 14 days groups). Collagen fibres were found to align in a preferred direction for all infarct groups supporting the observed mechanical anisotropy. The presented data are useful for developing material models for healing infarcts and for setting a baseline for future assessment of emerging mechanical-based MI therapies.
(Copyright © 2016 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
Externí odkaz: