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Ghosh S, Cimino JG, Scott AK, Damen FW, Phillips EH, Veress AI, Neu CP, Goergen CJ. In Vivo Multiscale and Spatially-Dependent Biomechanics Reveals Differential Strain Transfer Hierarchy in Skeletal Muscle. ACS Biomater Sci Eng 2017; 3:2798-2805. [PMID: 29276759 DOI: 10.1021/acsbiomaterials.6b00772] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Biological tissues have a complex hierarchical architecture that spans organ to subcellular scales and comprises interconnected biophysical and biochemical machinery. Mechanotransduction, gene regulation, gene protection, and structure-function relationships in tissues depend on how force and strain are modulated from macro to micro scales, and vice versa. Traditionally, computational and experimental techniques have been used in common model systems (e.g., embryos) and simple strain measures were applied. But the hierarchical transfer of mechanical parameters like strain in mammalian systems is largely unexplored in vivo. Here, we experimentally probed complex strain transfer processes in mammalian skeletal muscle tissue over multiple biological scales using complementary in vivo ultrasound and optical imaging approaches. An iterative hyperelastic warping technique quantified the spatially-dependent strain distributions in tissue, matrix, and subcellular (nuclear) structures, and revealed a surprising increase in strain magnitude and heterogeneity in active muscle as the spatial scale also increased. The multiscale strain heterogeneity indicates tight regulation of mechanical signals to the nuclei of individual cells in active muscle, and an emergent behavior appearing at larger (e.g. tissue) scales characterized by dramatically increased strain complexity.
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Affiliation(s)
- Soham Ghosh
- Department of Mechanical Engineering, University of Colorado Boulder, 1111 Engineering Drive, UCB 427, Boulder, Colorado 80309, United States
| | - James G Cimino
- Weldon School of Biomedical Engineering, Purdue University, 206 S Martin Jischke Drive, West Lafayette, Indiana 47907, United States
| | - Adrienne K Scott
- Department of Mechanical Engineering, University of Colorado Boulder, 1111 Engineering Drive, UCB 427, Boulder, Colorado 80309, United States
| | - Frederick W Damen
- Weldon School of Biomedical Engineering, Purdue University, 206 S Martin Jischke Drive, West Lafayette, Indiana 47907, United States
| | - Evan H Phillips
- Weldon School of Biomedical Engineering, Purdue University, 206 S Martin Jischke Drive, West Lafayette, Indiana 47907, United States
| | - Alexander I Veress
- Department of Mechanical Engineering, University of Washington, 352600 Stevens Way, Seattle, Washington 98195, United States
| | - Corey P Neu
- Department of Mechanical Engineering, University of Colorado Boulder, 1111 Engineering Drive, UCB 427, Boulder, Colorado 80309, United States.,Weldon School of Biomedical Engineering, Purdue University, 206 S Martin Jischke Drive, West Lafayette, Indiana 47907, United States
| | - Craig J Goergen
- Weldon School of Biomedical Engineering, Purdue University, 206 S Martin Jischke Drive, West Lafayette, Indiana 47907, United States
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Ghosh S, Ozcelikkale A, Dutton JC, Han B. Role of intracellular poroelasticity on freezing-induced deformation of cells in engineered tissues. J R Soc Interface 2016; 13:rsif.2016.0480. [PMID: 27707905 DOI: 10.1098/rsif.2016.0480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 09/06/2016] [Indexed: 11/12/2022] Open
Abstract
Freezing of biomaterials is important in a wide variety of biomedical applications, including cryopreservation and cryosurgeries. For the success of these applications to various biomaterials, biophysical mechanisms, which determine freezing-induced changes in cells and tissues, need to be well understood. Specifically, the significance of the intracellular mechanics during freezing is not well understood. Thus, we hypothesize that cells interact during freezing with the surroundings such as suspension media and the extracellular matrix (ECM) via two distinct but related mechanisms-water transport and cytoskeletal mechanics. The underlying rationale is that the cytoplasm of the cells has poroelastic nature, which can regulate both cellular water transport and cytoskeletal mechanics. A poroelasticity-based cell dehydration model is developed and confirmed to provide insight into the effects of the hydraulic conductivity and stiffness of the cytoplasm on the dehydration of cells in suspension during freezing. We further investigated the effect of the cytoskeletal structures on the cryoresponse of cells embedded in the ECM by measuring the spatio-temporal intracellular deformation with dermal equivalent as a model tissue. The freezing-induced change in cell, nucleus and cytoplasm volume was quantified, and the possible mechanism of the volumetric change was proposed. The results are discussed considering the hierarchical poroelasticity of biological tissues.
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Affiliation(s)
- Soham Ghosh
- School of Mechanical Engineering, Purdue University, West Lafayette, IN, USA
| | - Altug Ozcelikkale
- School of Mechanical Engineering, Purdue University, West Lafayette, IN, USA
| | - J Craig Dutton
- Department of Aerospace Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Bumsoo Han
- School of Mechanical Engineering, Purdue University, West Lafayette, IN, USA Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA Birck Nanotechnology Center, Purdue University, West Lafayette, IN, USA
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Park S, Seawright A, Park S, Craig Dutton J, Grinnell F, Han B. Preservation of tissue microstructure and functionality during freezing by modulation of cytoskeletal structure. J Mech Behav Biomed Mater 2015; 45:32-44. [PMID: 25679482 DOI: 10.1016/j.jmbbm.2015.01.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Revised: 01/13/2015] [Accepted: 01/16/2015] [Indexed: 02/06/2023]
Abstract
Cryopreservation is one of the key enabling technologies for tissue engineering and regenerative medicine, which can provide reliable long-term storage of engineered tissues (ETs) without losing their functionality. However, it is still extremely difficult to design and develop cryopreservation protocols guaranteeing the post-thaw tissue functionality. One of the major challenges in cryopreservation is associated with the difficulty of identifying effective and less toxic cryoprotective agents (CPAs) to guarantee the post-thaw tissue functionality. In this study, thus, a hypothesis was tested that the modulation of the cytoskeletal structure of cells embedded in the extracellular matrix (ECM) can mitigate the freezing-induced changes of the functionality and can reduce the amount of CPA necessary to preserve the functionality of ETs during cryopreservation. In order to test this hypothesis, we prepared dermal equivalents by seeding fibroblasts in type I collagen matrices resulting in three different cytoskeletal structures. These ETs were exposed to various freeze/thaw (F/T) conditions with and without CPAs. The freezing-induced cell-fluid-matrix interactions and subsequent functional properties of the ETs were assessed. The results showed that the cytoskeletal structure and the use of CPA were strongly correlated to the preservation of the post-thaw functional properties. As the cytoskeletal structure became stronger via stress fiber formation, the ET's functionality was preserved better. It also reduced the necessary CPA concentration to preserve the post-thaw functionality. However, if the extent of the freezing-induced cell-fluid-matrix interaction was too excessive, the cytoskeletal structure was completely destroyed and the beneficial effects became minimal.
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Affiliation(s)
- Seungman Park
- School of Mechanical Engineering, Purdue University, West Lafayette, IN, USA
| | - Angela Seawright
- School of Mechanical Engineering, Purdue University, West Lafayette, IN, USA
| | - Sinwook Park
- School of Mechanical Engineering, Purdue University, West Lafayette, IN, USA
| | - J Craig Dutton
- Department of Aerospace Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Frederick Grinnell
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Bumsoo Han
- School of Mechanical Engineering, Purdue University, West Lafayette, IN, USA; Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA; Birck Nanotechnology Center, Purdue University, West Lafayette, IN, USA.
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