The major challenges in biopolymer-based engineering of load-bearing tissues are mechanical- strength and stiffness. In vitro, as in vivo, properties are controlled by composition and architecture, on the nm-mu m scale of the fibril network. The functional scale is much larger, mm-cm. We will create, implement, validate, and disseminate a computational tool to predict functional scale mechanics based on a network-scale model of engineered tissues. The model will use volume-averaging theory to couple across scales, yielding a macroscopic equation set informed by microscopic behavior. The theory allows study of different systems by varying only the microscopic model. Coupling will occur at Gauss points of the macroscopic finite elements. P-adaptivity will be used to optimize distribution of Gauss points, and the software will operate in parallel to meet the computational demands of many microscopic-scale model solves. Experimental validation will be performed by comparison with two systems. Acellular fibrin-collagen co-gels have two distinct, relatively well-characterized networks. Cultured fibrin-based model tissues, in which entrapped smooth-muscle cells have secreted collagen and elastin, will be more difficult to characterize, but they will be a key step towards the goal of a general model of engineered tissue micromechanics. The program announcement identifies three critical expectations: collaboration, scale-bridging, and new understanding. Some of the team members have worked together in the past, but this project is a new link between mechanics, computational science, and tissue engineering. Likewise, it will link the microscopic scale (most easily controlled by the tissue engineer), and the macroscopic scale (needed for tissue performance). The lack of clear understanding of even simple artificial tissues presents an opportunity for major advancement by drawing on the microstructure to describe the material. This project is highly relevant to public health because of the large potential impact of engineered tissue, particularly structural cardiovascular tissue. Many people need replacement arteries or valves, and there are severe flaws with existing options, creating the need for a new generation of artificial tissues. Understanding, predicting, and controlling the mechanical properties of those tissues will be a critical step forward.

Agency
National Institute of Health (NIH)
Institute
National Institute of Biomedical Imaging and Bioengineering (NIBIB)
Type
Research Project (R01)
Project #
5R01EB005813-02
Application #
7104853
Study Section
Special Emphasis Panel (ZEB1-OSR-A (M1))
Program Officer
Kelley, Christine A
Project Start
2005-08-05
Project End
2008-05-31
Budget Start
2006-06-01
Budget End
2007-05-31
Support Year
2
Fiscal Year
2006
Total Cost
$322,218
Indirect Cost
Name
University of Minnesota Twin Cities
Department
Biomedical Engineering
Type
Schools of Engineering
DUNS #
555917996
City
Minneapolis
State
MN
Country
United States
Zip Code
55455
Dhume, Rohit Y; Shih, Elizabeth D; Barocas, Victor H (2018) Multiscale model of fatigue of collagen gels. Biomech Model Mechanobiol :
Korenczuk, Christopher E; Votava, Lauren E; Dhume, Rohit Y et al. (2017) Isotropic Failure Criteria Are Not Appropriate for Anisotropic Fibrous Biological Tissues. J Biomech Eng 139:
Witzenburg, Colleen M; Dhume, Rohit Y; Shah, Sachin B et al. (2017) Failure of the Porcine Ascending Aorta: Multidirectional Experiments and a Unifying Microstructural Model. J Biomech Eng 139:
Lai, Victor K; Nedrelow, David S; Lake, Spencer P et al. (2016) Swelling of Collagen-Hyaluronic Acid Co-Gels: An In Vitro Residual Stress Model. Ann Biomed Eng 44:2984-2993
Ban, Ehsan; Barocas, Victor H; Shephard, Mark S et al. (2016) Softening in Random Networks of Non-Identical Beams. J Mech Phys Solids 87:38-50
Witzenburg, Colleen M; Barocas, Victor H (2016) A nonlinear anisotropic inverse method for computational dissection of inhomogeneous planar tissues. Comput Methods Biomech Biomed Engin 19:1630-46
Witzenburg, Colleen M; Dhume, Rohit Y; Lake, Spencer P et al. (2016) Automatic Segmentation of Mechanically Inhomogeneous Tissues Based on Deformation Gradient Jump. IEEE Trans Med Imaging 35:29-41
Ban, Ehsan; Barocas, Victor H; Shephard, Mark S et al. (2016) Effect of Fiber Crimp on the Elasticity of Random Fiber Networks With and Without Embedding Matrices. J Appl Mech 83:0410081-410087
Zhang, Yanhang; Barocas, Victor H; Berceli, Scott A et al. (2016) Multi-scale Modeling of the Cardiovascular System: Disease Development, Progression, and Clinical Intervention. Ann Biomed Eng 44:2642-60
Gyoneva, Lazarina; Hovell, Carley B; Pewowaruk, Ryan J et al. (2016) Cell-matrix interaction during strain-dependent remodelling of simulated collagen networks. Interface Focus 6:20150069

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