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Design of a Mechanobioreactor to Apply Anisotropic, Biaxial Strain to Large Thin Biomaterials for Tissue Engineered Heart Valve Applications. Ann Biomed Eng 2022; 50:1073-1089. [PMID: 35622208 DOI: 10.1007/s10439-022-02984-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 05/16/2022] [Indexed: 01/05/2023]
Abstract
Repair and replacement solutions for congenitally diseased heart valves capable of post-surgery growth and adaptation have remained elusive. Tissue engineered heart valves (TEHVs) offer a potential biological solution that addresses the drawbacks of existing valve replacements. Typically, TEHVs are made from thin, fibrous biomaterials that either become cell populated in vitro or in situ. Often, TEHV designs poorly mimic the anisotropic mechanical properties of healthy native valves leading to inadequate biomechanical function. Mechanical conditioning of engineered tissues with anisotropic strain application can induce extracellular matrix remodelling to alter the anisotropic mechanical properties of a construct, but implementation has been limited to small-scale set-ups. To address this limitation for TEHV applications, we designed and built a mechanobioreactor capable of modulating biaxial strain anisotropy applied to large, thin, biomaterial sheets in vitro. The bioreactor can independently control two orthogonal stretch axes to modulate applied strain anisotropy on biomaterial sheets from 13 × 13 mm2 to 70 × 40 mm2. A design of experiments was performed using experimentally validated finite element (FE) models and demonstrated that biaxial strain was applied uniformly over a larger percentage of the cell seeded area for larger sheets (13 × 13 mm2: 58% of sheet area vs. 52 × 31 mm2: 86% of sheet area). Furthermore, bioreactor prototypes demonstrated that over 70% of the cell seeding area remained uniformly strained under different prescribed protocols: equibiaxial amplitudes between 5 to 40%, cyclic frequencies between 0.1 to 2.5 Hz and anisotropic strain ratios between 0:1 (constrained uniaxial) to 2:1. Lastly, proof-of-concept experiments were conducted where we applied equibiaxial (εx = εy = 8.75%) and anisotropic (εx = 12.5%, εy = 5%) strain protocols to cell-seeded, electrospun scaffolds. Cell nuclei and F-actin aligned to the vector-sum strain direction of each prescribed protocol (nuclei alignment: equibiaxial: 43.2° ± 1.8°, anisotropic: 17.5° ± 1.7°; p < 0.001). The abilities of this bioreactor to prescribe different strain amplitude, frequency and strain anisotropy protocols to cell-seeded scaffolds will enable future studies into the effects of anisotropic loading protocols on mechanically conditioned TEHVs and other engineered planar connective tissues.
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Carvalho E, Morais M, Ferreira H, Silva M, Guimarães S, Pêgo A. A paradigm shift: Bioengineering meets mechanobiology towards overcoming remyelination failure. Biomaterials 2022; 283:121427. [DOI: 10.1016/j.biomaterials.2022.121427] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 01/31/2022] [Accepted: 02/17/2022] [Indexed: 12/14/2022]
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Malladi S, Miranda-Nieves D, Leng L, Grainger SJ, Tarabanis C, Nesmith AP, Kosaraju R, Haller CA, Parker KK, Chaikof EL, Günther A. Continuous Formation of Ultrathin, Strong Collagen Sheets with Tunable Anisotropy and Compaction. ACS Biomater Sci Eng 2020; 6:4236-4246. [PMID: 32685675 PMCID: PMC7362332 DOI: 10.1021/acsbiomaterials.0c00321] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 05/26/2020] [Indexed: 01/08/2023]
Abstract
The multiscale organization of protein-based fibrillar materials is a hallmark of many organs, but the recapitulation of hierarchal structures down to fibrillar scales, which is a requirement for withstanding physiological loading forces, has been challenging. We present a microfluidic strategy for the continuous, large-scale formation of strong, handleable, free-standing, multicentimeter-wide collagen sheets of unprecedented thinness through the application of hydrodynamic focusing with the simultaneous imposition of strain. Sheets as thin as 1.9 μm displayed tensile strengths of 0.5-2.7 MPa, Young's moduli of 3-36 MPa, and modulated the diffusion of molecules as a function of collagen nanoscale structure. Smooth muscle cells cultured on engineered sheets oriented in the direction of aligned collagen fibrils and generated coordinated vasomotor responses. The described biofabrication approach enables rapid formation of ultrathin collagen sheets that withstand physiologically relevant loads for applications in tissue engineering and regenerative medicine, as well as in organ-on-chip and biohybrid devices.
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Affiliation(s)
- Shashi Malladi
- Department
of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario M5S3G8, Canada
| | - David Miranda-Nieves
- Division
of Health Sciences and Technology, Massachusetts
Institute of Technology, Cambridge, Massachusetts 02139, United States
- Department
of Surgery, Beth Israel Deaconess Medical
Center, Boston, Massachusetts 02115, United States
- Wyss
Institute for Biologically Inspired Engineering of Harvard University, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Lian Leng
- Department
of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario M5S3G8, Canada
| | - Stephanie J. Grainger
- Department
of Surgery, Beth Israel Deaconess Medical
Center, Boston, Massachusetts 02115, United States
| | - Constantine Tarabanis
- Department
of Surgery, Beth Israel Deaconess Medical
Center, Boston, Massachusetts 02115, United States
| | - Alexander P. Nesmith
- Wyss
Institute for Biologically Inspired Engineering of Harvard University, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Revanth Kosaraju
- Department
of Surgery, Beth Israel Deaconess Medical
Center, Boston, Massachusetts 02115, United States
| | - Carolyn A. Haller
- Department
of Surgery, Beth Israel Deaconess Medical
Center, Boston, Massachusetts 02115, United States
| | - Kevin Kit Parker
- Wyss
Institute for Biologically Inspired Engineering of Harvard University, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Elliot L. Chaikof
- Division
of Health Sciences and Technology, Massachusetts
Institute of Technology, Cambridge, Massachusetts 02139, United States
- Department
of Surgery, Beth Israel Deaconess Medical
Center, Boston, Massachusetts 02115, United States
- Wyss
Institute for Biologically Inspired Engineering of Harvard University, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Axel Günther
- Department
of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario M5S3G8, Canada
- Institute
of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada
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Haase K, Pelling AE. Investigating cell mechanics with atomic force microscopy. J R Soc Interface 2015; 12:20140970. [PMID: 25589563 PMCID: PMC4345470 DOI: 10.1098/rsif.2014.0970] [Citation(s) in RCA: 216] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Accepted: 12/18/2014] [Indexed: 12/12/2022] Open
Abstract
Transmission of mechanical force is crucial for normal cell development and functioning. However, the process of mechanotransduction cannot be studied in isolation from cell mechanics. Thus, in order to understand how cells 'feel', we must first understand how they deform and recover from physical perturbations. Owing to its versatility, atomic force microscopy (AFM) has become a popular tool to study intrinsic cellular mechanical properties. Used to directly manipulate and examine whole and subcellular reactions, AFM allows for top-down and reconstitutive approaches to mechanical characterization. These studies show that the responses of cells and their components are complex, and largely depend on the magnitude and time scale of loading. In this review, we generally describe the mechanotransductive process through discussion of well-known mechanosensors. We then focus on discussion of recent examples where AFM is used to specifically probe the elastic and inelastic responses of single cells undergoing deformation. We present a brief overview of classical and current models often used to characterize observed cellular phenomena in response to force. Both simple mechanistic models and complex nonlinear models have been used to describe the observed cellular behaviours, however a unifying description of cell mechanics has not yet been resolved.
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Affiliation(s)
- Kristina Haase
- Department of Physics, Centre for Interdisciplinary NanoPhysics, MacDonald Hall, University of Ottawa, 150 Louis Pasteur, Ottawa, Ontario, Canada
| | - Andrew E Pelling
- Department of Physics, Centre for Interdisciplinary NanoPhysics, MacDonald Hall, University of Ottawa, 150 Louis Pasteur, Ottawa, Ontario, Canada Department of Biology, Gendron Hall, 30 Marie Curie, University of Ottawa, Ottawa, Ontario, Canada Institute for Science Society and Policy, Desmarais Building, 55 Laurier Ave. East, University of Ottawa, Ottawa, Ontario, Canada K1N 6N5
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