Effects of hydrogel injection on borderzone contractility post-myocardial infarction
- 165 Downloads
Injectable hydrogels are a potential therapy for mitigating adverse left ventricular (LV) remodeling after myocardial infarction (MI). Previous studies using magnetic resonance imaging (MRI) have shown that hydrogel treatment improves systolic strain in the borderzone (BZ) region surrounding the infarct. However, the corresponding contractile properties of the BZ myocardium are still unknown. The goal of the current study was to quantify the in vivo contractile properties of the BZ myocardium post-MI in an ovine model treated with an injectable hydrogel. Contractile properties were determined 8 weeks following posterolateral MI by minimizing the difference between in vivo strains and volume calculated from MRI and finite element model predicted strains and volume. This was accomplished by using a combination of MRI, catheterization, finite element modeling, and numerical optimization. Results show contractility in the BZ of animals treated with hydrogel injection was significantly higher than untreated controls. End-systolic (ES) fiber stress was also greatly reduced in the BZ of treated animals. The passive stiffness of the treated infarct region was found to be greater than the untreated control. Additionally, the wall thickness in the infarct and BZ regions was found to be significantly higher in the treated animals. Treatment with hydrogel injection significantly improved BZ function and reduced LV remodeling, via altered MI properties. These changes are linked to a reduction in the ES fiber stress in the BZ myocardium surrounding the infarct. The current results imply that injectable hydrogels could be a viable therapy for maintaining LV function post-MI.
KeywordsBiomaterial Left ventricular remodeling Mechanical properties Magnetic resonance imaging Finite element analysis
This study was supported by a Predoctoral Fellowship from the American Heart Association (C. Rodell), by National Institutes of Health Grants R01 HL063954 (R. Gorman) and R01 HL111090 (J. Burdick), by a grant from the National Science Foundation CMMI-1538754 (J. Wenk), and by a grant from the Shandong Province Natural Science Foundation, China ZR201709220101 (H. Wang).
Compliance with ethical standards
Conflict of interest
No conflicts of interest, financial or otherwise, are declared by the author(s).
- Blom AS et al (2007) Ventricular restraint prevents infarct expansion and improves borderzone function after myocardial infarction: a study using magnetic resonance imaging, three-dimensional surface modeling, and myocardial tagging. Ann Thorac Surg 84:2004–2010. https://doi.org/10.1016/j.athoracsur.2007.06.062 CrossRefGoogle Scholar
- Rodell CB, MacArthur JW, Dorsey SM, Wade RJ, Wang LL, Woo YJ, Burdick JA (2015) Shear-thinning supramolecular hydrogels with secondary autonomous covalent crosslinking to modulate viscoelastic properties in vivo. Adv Funct Mater 25:636–644. https://doi.org/10.1002/adfm.201403550 CrossRefGoogle Scholar
- Wilson EM et al (2003) Region- and type-specific induction of matrix metalloproteinases in post-myocardial infarction remodeling. Circulation 107:2857–2863. https://doi.org/10.1161/01.CIR.0000068375.40887.FA CrossRefGoogle Scholar
- Zhu Y, Matsumura Y, Wagner WR (2017) Ventricular wall biomaterial injection therapy after myocardial infarction: advances in material design, mechanistic insight and early clinical experiences. Biomaterials 129:37–53. https://doi.org/10.1016/j.biomaterials.2017.02.032 CrossRefGoogle Scholar