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Pneumatic unidirectional cell stretching device for mechanobiological studies of cardiomyocytes. Biomech Model Mechanobiol 2019; 19:291-303. [PMID: 31444593 PMCID: PMC7005075 DOI: 10.1007/s10237-019-01211-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Accepted: 08/02/2019] [Indexed: 12/21/2022]
Abstract
In this paper, we present a transparent mechanical stimulation device capable of uniaxial stimulation, which is compatible with standard bioanalytical methods used in cellular mechanobiology. We validate the functionality of the uniaxial stimulation system using human-induced pluripotent stem cells-derived cardiomyocytes (hiPSC-CMs). The pneumatically controlled device is fabricated from polydimethylsiloxane (PDMS) and provides uniaxial strain and superior optical performance compatible with standard inverted microscopy techniques used for bioanalytics (e.g., fluorescence microscopy and calcium imaging). Therefore, it allows for a continuous investigation of the cell state during stretching experiments. The paper introduces design and fabrication of the device, characterizes the mechanical performance of the device and demonstrates the compatibility with standard bioanalytical analysis tools. Imaging modalities, such as high-resolution live cell phase contrast imaging and video recordings, fluorescent imaging and calcium imaging are possible to perform in the device. Utilizing the different imaging modalities and proposed stretching device, we demonstrate the capability of the device for extensive further studies of hiPSC-CMs. We also demonstrate that sarcomere structures of hiPSC-CMs organize and orient perpendicular to uniaxial strain axis and thus express more maturated nature of cardiomyocytes.
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Baudequin T, Legallais C, Bedoui F. In Vitro Bone Cell Response to Tensile Mechanical Solicitations: Is There an Optimal Protocol? Biotechnol J 2018; 14:e1800358. [PMID: 30350925 DOI: 10.1002/biot.201800358] [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: 06/26/2018] [Revised: 10/10/2018] [Indexed: 11/07/2022]
Abstract
Bone remodeling is strongly linked to external mechanical signals. Such stimuli are widely used in vitro for bone tissue engineering by applying mechanical solicitations to cell cultures so as to trigger specific cell responses. However, the literature highlights considerable variability in devices and protocols. Here the major biological, mechanical, and technical parameters implemented for in vitro tensile loading applications are reviewed. The objective is to identify which values are used most, and whether there is an optimal protocol to obtain a functional tissue-engineering construct. First, a shift that occurred from fundamental comprehension of bone formation, to its application in rebuilt tissues and clinical fields is shown. Despite the lack of standardized protocols, consensual conditions relevant for in vitro bone development, in particular cell differentiation, could be highlighted. Culture processes are guided by physiological considerations, although out-of-range conditions are sometimes used without implying negative results for the development of rebuilt tissue. Consensus can be found on several parameters, such as strain frequency (1 Hz) or the use of rest periods, but other points have not yet been fully established, especially synergies with other solicitations. It is believed that the present work will be useful to develop new tissue-engineering processes based on stretching.
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Affiliation(s)
- Timothée Baudequin
- Sorbonne Universités, Université de Technologie de Compiègne, CNRS, UMR 7338 Biomécanique - Bioingénierie, Compiègne 60205, France
| | - Cécile Legallais
- Sorbonne Universités, Université de Technologie de Compiègne, CNRS, UMR 7338 Biomécanique - Bioingénierie, Compiègne 60205, France
| | - Fahmi Bedoui
- Sorbonne Universités, Université de Technologie de Compiègne, CNRS, UMR 7337 Laboratoire Roberval, Compiègne 60205, France
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Abstract
The focus of this paper is to describe the mechanism and behavior of two-dimensional in vitro cell stretch platforms, as well as discussing designs for the evaluation of mechanical properties of cells. It is extremely important to understand the cellular response to extrinsic mechanical forces as living biological system is constantly subjected to mechanical forces in vivo. In addition, this mechanistic understanding of cellular response will provide valuable information towards the design and fabrication of bioengineered tissues and organs, which are expected to replace and/or aid bodily functions. This paper will primarily focus on the development, advantages and limitations of two-dimensional cell stretch platforms.
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Affiliation(s)
- H. GHAZIZADEH
- Joint School of Nanoscience and Nanoengineering, North Carolina A&T State University, 2907 East Gate City Blvd., Greensboro, NC 27401, USA
| | - S. ARAVAMUDHAN
- Joint School of Nanoscience and Nanoengineering, North Carolina A&T State University, 2907 East Gate City Blvd., Greensboro, NC 27401, USA
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Lee J, Baker AB. Computational analysis of fluid flow within a device for applying biaxial strain to cultured cells. J Biomech Eng 2015; 137:051006. [PMID: 25611013 DOI: 10.1115/1.4029638] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Indexed: 11/08/2022]
Abstract
In vitro systems for applying mechanical strain to cultured cells are commonly used to investigate cellular mechanotransduction pathways in a variety of cell types. These systems often apply mechanical forces to a flexible membrane on which cells are cultured. A consequence of the motion of the membrane in these systems is the generation of flow and the unintended application of shear stress to the cells. We recently described a flexible system for applying mechanical strain to cultured cells, which uses a linear motor to drive a piston array to create biaxial strain within multiwell culture plates. To better understand the fluidic stresses generated by this system and other systems of this type, we created a computational fluid dynamics model to simulate the flow during the mechanical loading cycle. Alterations in the frequency or maximal strain magnitude led to a linear increase in the average fluid velocity within the well and a nonlinear increase in the shear stress at the culture surface over the ranges tested (0.5-2.0 Hz and 1-10% maximal strain). For all cases, the applied shear stresses were relatively low and on the order of millipascal with a dynamic waveform having a primary and secondary peak in the shear stress over a single mechanical strain cycle. These findings should be considered when interpreting experimental results using these devices, particularly in the case when the cell type used is sensitive to low magnitude, oscillatory shear stresses.
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Tucker RP, Henningsson P, Franklin SL, Chen D, Ventikos Y, Bomphrey RJ, Thompson MS. See-saw rocking: an in vitro model for mechanotransduction research. J R Soc Interface 2015; 11:20140330. [PMID: 24898022 DOI: 10.1098/rsif.2014.0330] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In vitro mechanotransduction studies, uncovering the basic science of the response of cells to mechanical forces, are essential for progress in tissue engineering and its clinical application. Many varying investigations have described a multitude of cell responses; however, as the precise nature and magnitude of the stresses applied are infrequently reported and rarely validated, the experiments are often not comparable, limiting research progress. This paper provides physical and biological validation of a widely available fluid stimulation device, a see-saw rocker, as an in vitro model for cyclic fluid shear stress mechanotransduction. This allows linkage between precisely characterized stimuli and cell monolayer response in a convenient six-well plate format. Models of one well were discretized and analysed extensively using computational fluid dynamics to generate convergent, stable and consistent predictions of the cyclic fluid velocity vectors at a rocking frequency of 0.5 Hz, accounting for the free surface. Validation was provided by comparison with flow velocities measured experimentally using particle image velocimetry. Qualitative flow behaviour was matched and quantitative analysis showed agreement at representative locations and time points. Maximum shear stress of 0.22 Pa was estimated near the well edge, and time-average shear stress ranged between 0.029 and 0.068 Pa. Human tenocytes stimulated using the system showed significant increases in collagen and GAG secretion at 2 and 7 day time points. This in vitro model for mechanotransduction provides a versatile, flexible and inexpensive method for the fluid shear stress impact on biological cells to be studied.
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Affiliation(s)
- R P Tucker
- Department of Engineering Science, Institute of Biomedical Engineering, University of Oxford, Botnar Research Centre, Oxford OX3 7LD, UK
| | - P Henningsson
- Department of Zoology, University of Oxford, Botnar Research Centre, Oxford OX3 7LD, UK Department of Biology, Lund University, Lund, Sweden
| | - S L Franklin
- Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Botnar Research Centre, Oxford OX3 7LD, UK
| | - D Chen
- School of Life Science, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Y Ventikos
- Department of Engineering Science, Institute of Biomedical Engineering, University of Oxford, Botnar Research Centre, Oxford OX3 7LD, UK Department of Mechanical Engineering, University College London, London WC1E 6BT, UK
| | - R J Bomphrey
- Department of Zoology, University of Oxford, Botnar Research Centre, Oxford OX3 7LD, UK Structure and Motion Laboratory, Royal Veterinary College, Hatfield AL9 7TA, UK
| | - M S Thompson
- Department of Engineering Science, Institute of Biomedical Engineering, University of Oxford, Botnar Research Centre, Oxford OX3 7LD, UK
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Mechanical Analysis of a Pneumatically Actuated Concentric Double-Shell Structure for Cell Stretching. MICROMACHINES 2014. [DOI: 10.3390/mi5040868] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Han X, Guo L, Wang F, Zhu Q, Yang L. Contribution of PTHrP to mechanical strain-induced fibrochondrogenic differentiation in entheses of Achilles tendon of miniature pigs. J Biomech 2014; 47:2406-14. [DOI: 10.1016/j.jbiomech.2014.04.022] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Revised: 04/09/2014] [Accepted: 04/11/2014] [Indexed: 01/21/2023]
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Moles MD, Scotchford CA, Ritchie AC. Development of an elastic cell culture substrate for a novel uniaxial tensile strain bioreactor. J Biomed Mater Res A 2013; 102:2356-64. [PMID: 23946144 PMCID: PMC4255296 DOI: 10.1002/jbm.a.34917] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Revised: 07/30/2013] [Accepted: 08/09/2013] [Indexed: 02/01/2023]
Abstract
Bioreactors can be used for mechanical conditioning and to investigate the mechanobiology of cells in vitro. In this study a polyurethane (PU), Chronoflex AL, was evaluated for use as a flexible cell culture substrate in a novel bioreactor capable of imparting cyclic uniaxial tensile strain to cells. PU membranes were plasma etched, across a range of operating parameters, in oxygen. Contact angle analysis and X-ray photoelectron spectroscopy showed increases in wettability and surface oxygen were related to both etching power and duration. Atomic force microscopy demonstrated that surface roughness decreased after etching at 20 W but was increased at higher powers. The etching parameters, 20 W 40 s, produced membranes with high surface oxygen content (21%), a contact angle of 66° ± 7° and reduced topographical features. Etching and protein conditioning membranes facilitated attachment, and growth to confluence within 3 days, of MG-63 osteoblasts. After 2 days with uniaxial strain (1%, 30 cycles/min, 1500 cycles/day), cellular alignment was observed perpendicular to the principal strain axis, and found to increase after 24 h. The results indicate that the membrane supports culture and strain transmission to adhered cells. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 2356–2364, 2014.
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Affiliation(s)
- Matthew D Moles
- Division of Materials, Mechanics and Structures, Faculty of Mechanical, Materials and Manufacturing Engineering, University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom
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Thompson MS. Tendon mechanobiology: experimental models require mathematical underpinning. Bull Math Biol 2013; 75:1238-54. [PMID: 23681792 DOI: 10.1007/s11538-013-9850-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Accepted: 04/25/2013] [Indexed: 10/26/2022]
Abstract
Mathematical and computational modeling is in demand to help address current challenges in mechanobiology of musculoskeletal tissues. In particular for tendon, the high clinical importance of the tissue, the huge mechanical demands placed on it and its ability to adapt to these demands, require coupled, multiscale models incorporating complex geometrical and microstructural information as well as time-based descriptions of cellular activity and response.This review introduces the information sources required to develop such multiscale models. It covers tissue structure and biomechanics, cell biomechanics, the current understanding of tendon's ability in health and disease to update its properties and structure and the few already existing multiscale mechanobiological models of the tissue. Finally, a sketch is provided of what such models could achieve ideally, pointing out where experimental data and knowledge are still missing.
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Affiliation(s)
- Mark S Thompson
- Institute of Biomedical Engineering, Botnar Research Centre, University of Oxford, Windmill Road, Oxford, OX3 7LD, UK.
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