TY - JOUR
T1 - Experimental and computational investigation of altered mechanical properties in myocardium after hydrogel injection
AU - Kichula, Elena Tous
AU - Wang, Hua
AU - Dorsey, Shauna M.
AU - Szczesny, Spencer E.
AU - Elliott, Dawn M.
AU - Burdick, Jason A.
AU - Wenk, Jonathan F.
N1 - Funding Information:
The authors acknowledge Daniel Adler in assisting with the analysis of the MRI images. This work was supported by the National Institutes of Health (R01 HL111090, T32 HL007954).
PY - 2014/7
Y1 - 2014/7
N2 - The material properties of myocardium are an important determinant of global left ventricular function. Myocardial infarction results in a series of maladaptive geometric alterations which lead to increased stress and risk of heart failure. In vivo studies have demonstrated that material injection can mitigate these changes. More importantly, the material properties of these injectates can be tuned to minimize wall thinning and ventricular dilation. The current investigation combines experimental data and finite element modeling to correlate how injectate mechanics and volume influence myocardial wall stress. Experimentally, mechanics were characterized with biaxial testing and injected hydrogel volumes were measured with magnetic resonance imaging. Injection of hyaluronic acid hydrogel increased the stiffness of the myocardium/hydrogel composite region in an anisotropic manner, significantly increasing the modulus in the longitudinal direction compared to control myocardium. Increased stiffness, in combination with increased volume from hydrogel injection, reduced the global average fiber stress by ~14% and the transmural average by ~26% in the simulations. Additionally, stiffening in an anisotropic manner enhanced the influence of hydrogel treatment in decreasing stress. Overall, this work provides insight on how injectable biomaterials can be used to attenuate wall stress and provides tools to further optimize material properties for therapeutic applications.
AB - The material properties of myocardium are an important determinant of global left ventricular function. Myocardial infarction results in a series of maladaptive geometric alterations which lead to increased stress and risk of heart failure. In vivo studies have demonstrated that material injection can mitigate these changes. More importantly, the material properties of these injectates can be tuned to minimize wall thinning and ventricular dilation. The current investigation combines experimental data and finite element modeling to correlate how injectate mechanics and volume influence myocardial wall stress. Experimentally, mechanics were characterized with biaxial testing and injected hydrogel volumes were measured with magnetic resonance imaging. Injection of hyaluronic acid hydrogel increased the stiffness of the myocardium/hydrogel composite region in an anisotropic manner, significantly increasing the modulus in the longitudinal direction compared to control myocardium. Increased stiffness, in combination with increased volume from hydrogel injection, reduced the global average fiber stress by ~14% and the transmural average by ~26% in the simulations. Additionally, stiffening in an anisotropic manner enhanced the influence of hydrogel treatment in decreasing stress. Overall, this work provides insight on how injectable biomaterials can be used to attenuate wall stress and provides tools to further optimize material properties for therapeutic applications.
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U2 - 10.1007/s10439-013-0937-9
DO - 10.1007/s10439-013-0937-9
M3 - Article
C2 - 24271262
AN - SCOPUS:84904262322
SN - 0090-6964
VL - 42
SP - 1546
EP - 1556
JO - Annals of Biomedical Engineering
JF - Annals of Biomedical Engineering
IS - 7
ER -