Cellular strain assessment tool (CSAT): Precision-controlled cyclic uniaxial tensile loading

Yung, Yu Ching; Vandenburgh, Herman H.; Mooney, David J.

doi:10.1016/j.jbiomech.2008.10.038

Cited by 21 publications

(13 citation statements)

References 16 publications

(20 reference statements)

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“…In theory, a onedimensional gradient could be accomplished by uniaxially stretching a membrane produced with a gradient of stiffness or thickness; however, in practice, each of these scenarios would produce complex two-dimensional strain patterns due to the non-uniform stress patterns in the membrane and uneven lateral contraction (Poisson effect) along the length of the membrane. Recently, in an analogous method as used herein, Mooney and colleagues (Yung et al 2009) affixed a rigid rectangular glass material to the bottom of a uniaxially stretched planar compliant culture substrate in an effort to produce a one-dimensional strain gradient. Unfortunately, the two-dimensional deformation field resulting from this modification was not fully analyzed, thus the effects of the inclusion and culture well boundaries on the strain field are not clear.…”

Section: Benefit Of a Symmetric Biaxial Gradient System Over A Uniaximentioning

confidence: 99%

“…Cells have been shown to alter migration and proliferation in response to gradients of stiffness ("durotaxis" or "durokinesis") (Lo et al 2000), yet the effects of gradients of strain on cell migration (we term "tendotaxis") have only recently begun to be considered (Ohashi et al 2007;Yung et al 2009). Early cell stretching systems involved inflation of circularly clamped membranes, and inadvertently created radially symmetric strain gradients (Gilbert et al 1994;Williams et al 1992;Winston et al 1989;Yung et al 2009). These systems are however, no longer utilized extensively due to complex fluid stresses and difficulty in evaluating the strain field (caused by the out-of-plane motion of the membrane).…”

Section: Introductionmentioning

confidence: 99%

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Applying controlled non-uniform deformation for in vitro studies of cell mechanobiology

Balestrini

Skorinko

Hera

et al. 2010

Biomech Model Mechanobiol

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Cells within connective tissues routinely experience a wide range of non-uniform mechanical loads that regulate many cell behaviors. In this study, we developed an experimental system to produce complex strain patterns for the study of strain magnitude, anisotropy, and gradient effects on cells in culture. A standard equibiaxial cell stretching system was modified by affixing glass coverslips (5, 10, or 15 mm diameter) to the center of 35 mm diameter flexible-bottomed culture wells. Ring inserts were utilized to limit applied strain to different levels in each individual well at a given vacuum pressure thus enabling parallel experiments at different strain levels. Deformation fields were measured using high-density mapping for up to 6% applied strain. The addition of the rigid inclusion creates strong circumferential and radial strain gradients, with a continuous range of stretch anisotropy ranging from strip biaxial to equibiaxial strain and radial strains up to 24% near the inclusion. Dermal fibroblasts seeded within our 2D system (5 mm inclusions; 2% applied strain for 2 days at 0.2 Hz) demonstrated the characteristic orientation perpendicular to the direction of principal strain. Dermal fibroblasts seeded within fibrin gels (5 mm inclusions; 6% applied strain for 8 days at 0.2 Hz) oriented themselves similarly and compacted their surrounding matrix to an increasing extent with local strain magnitude. This study verifies how inhomogeneous strain fields can be produced in a tunable and simply constructed system and demonstrates the potential utility for studying gradients with a continuous spectrum of strain magnitudes and anisotropies.

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Section: Benefit Of a Symmetric Biaxial Gradient System Over A Uniaximentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Applying controlled non-uniform deformation for in vitro studies of cell mechanobiology

Balestrini

Skorinko

Hera

et al. 2010

Biomech Model Mechanobiol

View full text Add to dashboard Cite

show abstract

“…However, they do not quantify the,se behaviors, nor state whether this was the case for the majority of cells or just a sporadic finding, Yung et al, used a similar setup for their "cellular strain assessment tool." but after characterizing the mechanical environment of the uniaxial stretching device and quantifying an achievable gradient, the focus was retumed to homogeneous strain environments with no mention of a plan for studying the effects of the gradient [29].…”

Section: Discussionmentioning

confidence: 99%

A Device to Study the Effects of Stretch Gradients on Cell Behavior

Richardson

Metz

Moreno

et al. 2011

Journal of Biomechanical Engineering

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Mechanical forces are key regulators of cell function with varying loads capable of modulating behaviors such as alignment, migration, phenotype modulation, and others. Historically, cell-stretching experiments have employed mechanically simple environments (e.g., uniform uniaxial or equibiaxial stretches). However, stretch distributions in vivo can be highly non-uniform, particularly in cases of disease or subsequent to interventional treatments. Herein, we present a cell-stretching device capable of subjecting cells to controllable gradients in biaxial stretch via radial deformation of circular elastomeric membranes. By including either a defect or a rigid fixation at the center of the membrane, various gradients are generated. Capabilities of the device were quantified by tracking marked positions of the membrane while applying various loads, and experimental feasibility was assessed by conducting preliminary experiments with 3T3 fibroblasts and 10T1/2 cells subjected to 24 h of cyclic stretch. Quantitative real-time PCR was used to measure changes in mRNA expression of a profile of genes representing the major smooth muscle phenotypes. Genes associated with the contractile state were both upregulated (e.g., calponin) and downregulated (e.g., α-2-actin), and genes associated with the synthetic state were likewise both upregulated (e.g., SKI-like oncogene) and downregulated (e.g., collagen III). In addition, cells aligned with an orientation perpendicular to the maximal stretch direction. We have developed an in vitro cell culture device that can produce non-uniform stretch environments similar to in vivo mechanics. Cells stretched with this device showed alignment and altered mRNA expression indicative of phenotype modulation. Understanding these processes as they relate to in vivo pathologies could enable a more accurately targeted treatment to heal or inhibit disease, either through implantable device design or pharmaceutical approaches.

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“…Similar systems have been used in studies of neuronal axons [104] and lung epithelium/endothelium coculture [105]. Researchers can more accurately replicate in vivo conditions by stretching cells cultured in 3D gels in addition to 2D membranes [106,107]. Another important modification is live-cell visualization, which can open up new possibilities for relevant data collection during mechanostimulation studies [107,108].…”

Section: Strain Methodsmentioning

confidence: 99%

“…Researchers can more accurately replicate in vivo conditions by stretching cells cultured in 3D gels in addition to 2D membranes [106,107]. Another important modification is live-cell visualization, which can open up new possibilities for relevant data collection during mechanostimulation studies [107,108]. Several systems have been developed to facilitate live-cell imaging in uniaxial strain systems [95,106,108].…”

Section: Strain Methodsmentioning

confidence: 99%

Device-Based In Vitro Techniques for Mechanical Stimulation of Vascular Cells: A Review

Davis

Zambrano

Anumolu

et al. 2015

Journal of Biomechanical Engineering

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The most common cause of death in the developed world is cardiovascular disease. For decades, this has provided a powerful motivation to study the effects of mechanical forces on vascular cells in a controlled setting, since these cells have been implicated in the development of disease. Early efforts in the 1970 s included the first use of a parallel-plate flow system to apply shear stress to endothelial cells (ECs) and the development of uniaxial substrate stretching techniques (Krueger et al., 1971, "An in Vitro Study of Flow Response by Cells," J. Biomech., 4(1), pp. 31-36 and Meikle et al., 1979, "Rabbit Cranial Sutures in Vitro: A New Experimental Model for Studying the Response of Fibrous Joints to Mechanical Stress," Calcif. Tissue Int., 28(2), pp. 13-144). Since then, a multitude of in vitro devices have been designed and developed for mechanical stimulation of vascular cells and tissues in an effort to better understand their response to in vivo physiologic mechanical conditions. This article reviews the functional attributes of mechanical bioreactors developed in the 21st century, including their major advantages and disadvantages. Each of these systems has been categorized in terms of their primary loading modality: fluid shear stress (FSS), substrate distention, combined distention and fluid shear, or other applied forces. The goal of this article is to provide researchers with a survey of useful methodologies that can be adapted to studies in this area, and to clarify future possibilities for improved research methods.

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Cellular strain assessment tool (CSAT): Precision-controlled cyclic uniaxial tensile loading

Cited by 21 publications

References 16 publications

Applying controlled non-uniform deformation for in vitro studies of cell mechanobiology

Applying controlled non-uniform deformation for in vitro studies of cell mechanobiology

A Device to Study the Effects of Stretch Gradients on Cell Behavior

Device-Based In Vitro Techniques for Mechanical Stimulation of Vascular Cells: A Review

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