Pipette aspiration technique for the measurement of nonlinear and anisotropic mechanical properties of blood vessel walls under biaxial stretch

Ohashi, Toshiro; Abe, Hidetsugu; Matsumotο, Takeo; Sato, Masaaki

doi:10.1016/j.jbiomech.2004.09.019

Cited by 37 publications

(60 citation statements)

References 13 publications

(18 reference statements)

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“…Previous computational and experimental studies by Ohashi et al and Aoki et al investigated the ability of pipette aspiration to measure nonlinear finite elasticity of soft tissues. 17,18 Geometric influences were negligible if the tissue sample was at least 5 times the radius of the pipette in diameter and 4 times the radius of the pipette in thickness, which was the case in all of our tissue samples (supplemental Figure III). They then used strain energy based pseudoelasticity theory to model changes in local tissue mechanics, 18,19 and found that the principal tissue stress was equivalent to the applied pressure.…”

Section: Mesomechanical Testingmentioning

confidence: 84%

“…17,18 Geometric influences were negligible if the tissue sample was at least 5 times the radius of the pipette in diameter and 4 times the radius of the pipette in thickness, which was the case in all of our tissue samples (supplemental Figure III). They then used strain energy based pseudoelasticity theory to model changes in local tissue mechanics, 18,19 and found that the principal tissue stress was equivalent to the applied pressure. To apply this theory to embryonic cushions, it was therefore assumed that the cushion material response was homogeneous, isotropic, and nonlinear hyperelastic.…”

Section: Mesomechanical Testingmentioning

confidence: 84%

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Transitions in Early Embryonic Atrioventricular Valvular Function Correspond With Changes in Cushion Biomechanics That Are Predictable by Tissue Composition

Butcher

McQuinn

Sedmera

et al. 2007

Circulation Research

135

158

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Abstract-Endocardial cushions are critical to maintain unidirectional blood flow under constantly increasing hemodynamic forces, but the interrelationship between endocardial cushion structure and the mechanics of atrioventricular junction function is poorly understood. Atrioventricular (AV) canal motions and blood velocities of embryonic chicks at Hamburger and Hamilton (HH) stages 17, 21, and 25 were quantified using ultrasonography. Similar to the embryonic zebrafish heart, the HH17 AV segment functions like a suction pump, with the cushions expanding in a wave during peak myocardial contraction and becoming undetectable during the relaxation phase. By HH25, the AV canal contributes almost nothing to the piston-like propulsion of blood, but the cushions function as stoppers apposing blood flow with near constant thickness. Using a custom built mesomechanical testing system, we quantified the nonlinear pseudoelastic biomechanics of developing AV cushions, and found that both AV cushions increased in effective modulus between HH17 and HH25. Enzymatic digestion of major structural constituent collagens or glycosaminoglycans resulted in distinctly different stress-strain curves suggestive of their individual contributions. Mixture theory using histologically determined volume fractions of cells, collagen, and glycosaminoglycans showed good prediction of cushion material properties regardless of stage and cushion position. Key Words: chick Ⅲ development Ⅲ modeling Ⅲ ultrasound Ⅲ flow Ⅲ aspiration T he development of the atrioventricular (AV) and semilunar valves of the heart from the endocardial cushions occurs concomitantly with a constant barrage of hemodynamic and mechanical forces. Several studies have demonstrated that both blood pressure and velocities increase during morphological development in the heart, implying that the stresses on the endocardial cushions are also increasing. [1][2][3] Early investigations highlighted the motions of cushions in concert with the contracting myocardium, suggesting that they serve a valve-like function before valves form. 4 However, a recent study showed that the atrioventricular canal in the tubular early zebrafish heart functions like a suction pump, in contrast to the peristaltic mechanism previously described. 5 These observations raise no controversy with respect to current understanding of transitions that occur structurally and molecularly in the myocardium during early tube heart development, but raise major questions with respect to the mechanism through which endocardial cushions function in promoting unidirectional blood flow during the transition from tubular heart to a septated structure. In this study we examined the mechanical properties and myocardial/endocardial cushion mechanical interaction in 3 stages of cardiac development in the chick embryo to better understand how the mechanical properties of the cushions contribute to their functional roles.Various mutant models demonstrate that genetic defects compromising valve structural maturation result in s...

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Section: Mesomechanical Testingmentioning

confidence: 84%

Section: Mesomechanical Testingmentioning

confidence: 84%

Transitions in Early Embryonic Atrioventricular Valvular Function Correspond With Changes in Cushion Biomechanics That Are Predictable by Tissue Composition

Butcher

McQuinn

Sedmera

et al. 2007

Circulation Research

135

158

View full text Add to dashboard Cite

show abstract

“…One of the oldest andin principle-simplest methods is micropipette aspiration in which a sample is partly or completely aspirated into a micropipette (Mitchison and Swann, 1954;Tickle and Trinkaus, 1973;Nakamura and Hiramoto, 1978;Schmid-Schonbein et al, 1981;Engler et al, 2006;Merryman et al, 2006). The amount of displacement into the pipette at a given pressure difference provides a method for measuring tissue mechanical properties including stiffness and viscosity (Sato et al, 1990;Zhou et al, 2005;Boudou et al, 2006), or with some modifications, anisotropy and Poisson's ratio (Ohashi et al, 2005;Boudou et al, 2006).…”

Section: Methods For Assessing Embryo-to-embryo Variationmentioning

confidence: 99%

Variation and robustness of the mechanics of gastrulation: The role of tissue mechanical properties during morphogenesis

Dassow

Davidson

2007

Birth Defects Research Pt C

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Diverse mechanisms of morphogenesis generate a wide variety of animal forms. In this work, we discuss two ways that the mechanical properties of embryonic tissues could guide one of the earliest morphogenetic movements in animals, gastrulation. First, morphogenetic movements are a function of both the forces generated by cells and the mechanical properties of the tissues. Second, cells could change their behavior in response to their mechanical environment. Theoretical studies of gastrulation indicate that different morphogenetic mechanisms differ in their inherent sensitivity to tissue mechanical properties. Those few empirical studies that have investigated the mechanical properties of amphibian and echinoderm gastrula-stage embryos indicate that there could be high embryo-to-embryo variability in tissue stiffness. Such high embryo-to-embryo variability would imply that gastrulation is fairly robust to variation in tissue stiffness. Cell culture studies demonstrate a wide variety of cellular responses to the mechanical properties of their microenvironment. These responses are likely to be developmentally regulated, and could either increase or decrease the robustness of gastrulation movements depending on which cells express which responses. Hence both passive physical and mechanoregulatory processes will determine how sensitive gastrulation is to tissue mechanics. Addressing these questions is important for understanding the significance of diverse programs of early development, and how genetic or environmental perturbations influence development. We discuss methods for measuring embryo-to-embryo variability in tissue mechanics, and for experimentally perturbing those mechanical properties to determine the sensitivity of gastrulation to tissue mechanics.

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“…The mechanical properties of the aorta have been studied in the literature leading to several constitutive models (Bergel 1961;Dobrin 1978;Chandran and Vonesh 1998;Chuong and Fung 1983;Cox 1978;Dobrin and Mrkvicka 1992;Fung 1988). Both uniaxial (He and Roach 1994;Raghavan et al 1996;Thubrikar et al 2001;Prendergast et al 2003;Carew et al 2003;Vorp et al 2003;Doehring et al 2005;Holzapfel 2006;Sokolis et al 2006) and biaxial (Sacks and Sun 2003;Vande Geest et al 2004;Fukui et al 2005;Ohashi et al 2005) tensile tests have been used to determine the mechanical behavior of the arterial walls.…”

Section: Introductionmentioning

confidence: 99%

Effects of strain rate, mixing ratio, and stress–strain definition on the mechanical behavior of the polydimethylsiloxane (PDMS) material as related to its biological applications

Khanafer

Duprey

Schlicht

et al. 2008

Biomed Microdevices

237

165

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Tensile tests on Polydimethylsiloxane (PDMS) materials were conducted to illustrate the effects of mixing ratio, definition of the stress-strain curve, and the strain rate on the elastic modulus and stress-strain curve. PDMS specimens were prepared according to the ASTM standards for elastic materials. Our results indicate that the physiological elastic modulus depends strongly on the definition of the stress-strain curve, mixing ratio, and the strain rate. For various mixing ratios and strain rates, true stress-strain definition results in higher stress and elastic modulus compared with engineering stress-strain and true stress-engineering strain definitions. The elastic modulus increases as the mixing ratio increases up-to 9:1 ratio after which the elastic modulus begins to decrease even as the mixing ratio continues to increase. The results presented in this study will be helpful to assist the design of in vitro experiments to mimic blood flow in arteries and to understand the complex interaction between blood flow and the walls of arteries using PDMS elastomer.

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Pipette aspiration technique for the measurement of nonlinear and anisotropic mechanical properties of blood vessel walls under biaxial stretch

Cited by 37 publications

References 13 publications

Transitions in Early Embryonic Atrioventricular Valvular Function Correspond With Changes in Cushion Biomechanics That Are Predictable by Tissue Composition

Transitions in Early Embryonic Atrioventricular Valvular Function Correspond With Changes in Cushion Biomechanics That Are Predictable by Tissue Composition

Variation and robustness of the mechanics of gastrulation: The role of tissue mechanical properties during morphogenesis

Effects of strain rate, mixing ratio, and stress–strain definition on the mechanical behavior of the polydimethylsiloxane (PDMS) material as related to its biological applications

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