DIRECTIONAL BIOMECHANICAL PROPERTIES OF PORCINE SKIN TISSUE

2014 ◽  
Vol 14 (05) ◽  
pp. 1450069 ◽  
Author(s):  
HSIAO-YING SHADOW HUANG ◽  
SIYAO HUANG ◽  
COLIN P. FRAZIER ◽  
PETER M. PRIM ◽  
OLA HARRYSSON
Keyword(s):  
Material Properties ◽  
Collagen Fiber ◽  
Biomechanical Properties ◽  
Skin Tissue ◽  
Elastic Fibers ◽  
Fiber Direction ◽  
Porcine Skin ◽  
Biomechanical Behavior ◽  
Tissue Anisotropy ◽  
Biaxial Mechanical Properties

Skin is a multilayered composite material and composed principally of the proteins collagen, elastic fibers and fibroblasts. The direction-dependent material properties of skin tissue is important for physiological functions like skin expansion. The current study has developed methods to characterize the directional biomechanical properties of porcine skin tissues as studies have shown that pigs represent a useful animal model due to similarities between porcine and human skin. It is observed that skin tissue has a nonlinear anisotropy biomechanical behavior, where the parameters of material modulus is 378 ± 160 kPa in the preferred-fiber direction and 65.96 ± 40.49 kPa in the cross-fiber direction when stretching above 30% strain equibiaxially. The result from the study provides methods of characterizing biaxial mechanical properties of skin tissue, as the collagen fiber direction appears to be one of the primary determinants of tissue anisotropy.

scholarly journals A Biomechanical Study of Directional Mechanical Properties of Porcine Skin Tissues

2013 ◽  
Author(s):  
Hsiao-Ying Shadow Huang ◽  
Siyao Huang ◽  
Taylor Gettys ◽  
Peter M. Prim ◽  
Ola L. Harrysson
Keyword(s):  
Material Properties ◽  
Biomechanical Properties ◽  
Biomechanical Study ◽  
Skin Tissue ◽  
Elastic Fibers ◽  
Fiber Direction ◽  
Porcine Skin ◽  
Biomechanical Behavior ◽  
Skin Stretching ◽  
Material Stiffness

Skin is a multilayered composite material and composed principally of the proteins collagen, elastic fibers, and fibroblasts. The direction-dependent material properties of skin tissue is important for physiological functions like skin expansion. The current study has developed methods to characterize the directional biomechanical properties of porcine skin tissues. It is observed that skin tissue has a nonlinear anisotropy biomechanical behavior, where the parameters of material stiffness is 378 ±160 kPa in the preferred-fiber direction and 65.96±40.49 kPa in the cross-fiber direction when stretching above 30% strain equibiaxially. The results from the current study will help optimize functional skin stretching for patients requiring large surface area skin grafts and reconstructions due to burns or other injuries.

Die unterschiedliche Ausdehnung der Übergangszone in der Karotisgabel

VASA ◽  
2001 ◽  
Vol 30 (2) ◽  
pp. 101-106 ◽  
Author(s):  
J. Janzen ◽  
P. Lanzer ◽  
K. Rothenberger-Janzen ◽  
P.N. Vuong
Keyword(s):  
Carotid Artery ◽  
Transitional Zone ◽  
Biomechanical Properties ◽  
Elastic Fibers ◽  
Arterial Segment ◽  
Biomechanical Behavior ◽  
Atherosclerotic Lesions ◽  
The Media ◽  
Potential Factor ◽  
The Impact

Background: The goal of our study was to demonstrate the extension of the transitional zone (TZ) between elastic and muscular medial structure in carotid artery tripod. Patients and methods: A histologic study of 56 probes from 8 carotid artery tripods was performed. The probes were obtained from autopsies of 4 adults (mean age: 47.5 years, range 38 to 55 years) and were taken from 7 different topographic sites. Results: At each level of the CCA (at 1 cm and 2 cm proximal to the bifurcation as well as at the bifurcation) we observed an elastic arterial type in 24 (42.8%) probes with 11 to 20 (medium 15.0) elastic fibers per view field (200 ¥ magnification) in the media. In contrast the histologic structure of the ICA and ECA varied as follows: in 8 sections (14.3%) elastic arterial type with 11 to 16 (medium 13.1) elastic fibers, in 11 sections (19.6%) muscular arterial type with 2 to 5 (medium 3.5) elastic fibers and in 9 sections (16.1%) a transitional arterial type with 6 to 8 (medium 6.7) elastic fibers in the media. Atherosclerotic lesions have prevented the assessment of the arterial type in 4 probes (7.1%). The TZ in the medial structure of carotid artery tripods is exclusively localized in the ICA/ECA but not in the CCA. The ICA/ECA presented a TZ with a length up to 0.5 cm (4 probes; 25%), up to 1.5 cm (4 probes; 25%) and longer than 1.5 cm (6 probes; 37.5%). Conclusions: In this study we confirmed that in the carotid artery tripod, a TZ – an arterial segment with transition from elastic to muscular type – does exist, involving a variable length. Furthermore studies on the impact of the biomechanical properties of the TZ as a potential factor in atherosclerotic disease are justified. In addition, the complex biomechanical behavior of the TZ should be considered prior to interventional procedures.

scholarly journals Pigmentation Affects Elastic Fiber Patterning and Biomechanical Behavior of the Murine Aortic Valve

2021 ◽  
Vol 8 ◽  
Author(s):  
Sana Nasim ◽  
Popular Pandey ◽  
Rosemeire M. Kanashiro-Takeuchi ◽  
Jin He ◽  
Joshua D. Hutcheson ◽  
...  
Keyword(s):  
Aortic Valve ◽  
Elastic Fiber ◽  
Biomechanical Properties ◽  
Systemic Circulation ◽  
Elastic Fibers ◽  
Multiphoton Imaging ◽  
Force Microscopy ◽  
Biomechanical Behavior ◽  
Atomic Force ◽  
Fiber Organization

The aortic valve (AoV) maintains unidirectional blood distribution from the left ventricle of the heart to the aorta for systemic circulation. The AoV leaflets rely on a precise extracellular matrix microarchitecture of collagen, elastin, and proteoglycans for appropriate biomechanical performance. We have previously demonstrated a relationship between the presence of pigment in the mouse AoV with elastic fiber patterning using multiphoton imaging. Here, we extended those findings using wholemount confocal microscopy revealing that elastic fibers were diminished in the AoV of hypopigmented mice (KitWv and albino) and were disorganized in the AoV of K5-Edn3 transgenic hyperpigmented mice when compared to wild type C57BL/6J mice. We further used atomic force microscopy to measure stiffness differences in the wholemount AoV leaflets of mice with different levels of pigmentation. We show that AoV leaflets of K5-Edn3 had overall higher stiffness (4.42 ± 0.35 kPa) when compared to those from KitWv (2.22 ± 0.21 kPa), albino (2.45 ± 0.16 kPa), and C57BL/6J (3.0 ± 0.16 kPa) mice. Despite the striking elastic fiber phenotype and noted stiffness differences, adult mutant mice were found to have no overt cardiac differences as measured by echocardiography. Our results indicate that pigmentation, but not melanocytes, is required for proper elastic fiber organization in the mouse AoV and dictates its biomechanical properties.

Optimization of a decellularization protocol of porcine tracheas. Long-term effects of cryopreservation. A histological study

2021 ◽  
pp. 039139882110089
Author(s):  
Lara Milian ◽  
María Sancho-Tello ◽  
Joan Roig-Soriano ◽  
Giovanna Foschini ◽  
Néstor J Martínez-Hernández ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Histological Study ◽  
Biomechanical Properties ◽  
Elastic Fibers ◽  
Appreciable Effect ◽  
Long Term Effects ◽  
Minimal Impact ◽  
Biomechanical Effect ◽  
Triton X

Objective: The aim of this study was to optimize a decellularization protocol in the trachea of Sus scrofa domestica (pig) as well as to study the effects of long-term cryopreservation on the extracellular matrix of decellularized tracheas. Methods: Porcine tracheas were decellularized using Triton X-100, SDC, and SDS alone or in combination. The effect of these detergents on the extracellular matrix characteristics of decellularized porcine tracheas was evaluated at the histological, biomechanical, and biocompatibility level. Morphometric approaches were used to estimate the effect of detergents on the collagen and elastic fibers content as well as on the removal of chondrocytes from decellularized organs. Moreover, the long-term structural, ultrastructural, and biomechanical effect of cryopreservation of decellularized tracheas were also estimated. Results: Two percent SDS was the most effective detergent tested concerning cell removal and preservation of the histological and biomechanical properties of the tracheal wall. However, long-term cryopreservation had no an appreciable effect on the structure, ultrastructure, and biomechanics of decellularized tracheal rings. Conclusion: The results presented here reinforce the use of SDS as a valuable decellularizing agent for porcine tracheas. Furthermore, a cryogenic preservation protocol is described, which has minimal impact on the histological and biomechanical properties of decellularized porcine tracheas.

scholarly journals Material properties and effect of preconditioning of human sclera, optic nerve, and optic nerve sheath

2021 ◽  
Author(s):  
Joseph Park ◽  
Andrew Shin ◽  
Somaye Jafari ◽  
Joseph L. Demer
Keyword(s):  
Optic Nerve ◽  
Mechanical Behavior ◽  
Material Properties ◽  
Biomechanical Properties ◽  
Ocular Tissues ◽  
Tangent Moduli ◽  
Nonlinear Mechanical ◽  
Human Eyes ◽  
Range Of Variation ◽  
Great Stress

AbstractThe optic nerve (ON) is a recently recognized tractional load on the eye during larger horizontal eye rotations. In order to understand the mechanical behavior of the eye during adduction, it is necessary to characterize material properties of the sclera, ON, and in particular its sheath. We performed tensile loading of specimens taken from fresh postmortem human eyes to characterize the range of variation in their biomechanical properties and determine the effect of preconditioning. We fitted reduced polynomial hyperelastic models to represent the nonlinear tensile behavior of the anterior, equatorial, posterior, and peripapillary sclera, as well as the ON and its sheath. For comparison, we analyzed tangent moduli in low and high strain regions to represent stiffness. Scleral stiffness generally decreased from anterior to posterior ocular regions. The ON had the lowest tangent modulus, but was surrounded by a much stiffer sheath. The low-strain hyperelastic behaviors of adjacent anatomical regions of the ON, ON sheath, and posterior sclera were similar as appropriate to avoid discontinuities at their boundaries. Regional stiffnesses within individual eyes were moderately correlated, implying that mechanical properties in one region of an eye do not reliably reflect properties of another region of that eye, and that potentially pathological combinations could occur in an eye if regional properties are discrepant. Preconditioning modestly stiffened ocular tissues, except peripapillary sclera that softened. The nonlinear mechanical behavior of posterior ocular tissues permits their stresses to match closely at low strains, although progressively increasing strain causes particularly great stress in the peripapillary region.

scholarly journals Collagen Structure and Mechanical Properties of the Human Sclera: Analysis for the Effects of Age

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Baptiste Coudrillier ◽  
Jacek Pijanka ◽  
Joan Jefferys ◽  
Thomas Sorensen ◽  
Harry A. Quigley ◽  
...  
Keyword(s):  
Material Properties ◽  
Collagen Fiber ◽  
Image Correlation ◽  
Mechanical Anisotropy ◽  
Matrix Stiffness ◽  
Fiber Structure ◽  
Human Donor ◽  
Full Field ◽  
X Ray Scattering ◽  
The Difference

The objective of this study was to measure the collagen fiber structure and estimate the material properties of 7 human donor scleras, from age 53 to 91. The specimens were subjected to inflation testing, and the full-field displacement maps were measured by digital image correlation. After testing, the collagen fiber structure was mapped using wide-angle X-ray scattering. A specimen-specific inverse finite element method was applied to calculate the material properties of the collagen fibers and interfiber matrix by minimizing the difference between the experimental displacements and model predictions. Age effects on the fiber structure and material properties were estimated using multivariate models accounting for spatial autocorrelation. Older age was associated with a larger matrix stiffness (p = 0.001), a lower degree of fiber alignment in the peripapillary sclera (p = 0.01), and a lower mechanical anisotropy in the peripapillary sclera (p = 0.03).

Biaxial Mechanical Properties of Passive Right Ventricular Free Wall Myocardium

1993 ◽  
Vol 115 (2) ◽  
pp. 202-205 ◽  
Author(s):  
M. S. Sacks ◽  
C. J. Chuong
Keyword(s):  
Mechanical Properties ◽  
Right Ventricular ◽  
Mechanical Response ◽  
Ventricular Free Wall ◽  
Fiber Direction ◽  
Free Wall ◽  
Right Ventricular Free Wall ◽  
Tissue Specimens ◽  
Excised Tissue ◽  
Biaxial Mechanical Properties

The biaxial mechanical properties of right ventricular free wall (RVFW) myocardium were studied. Tissue specimens were obtained from the sub-epicardium of potassium-arrested hearts and different stretch protocols were used to characterize the myocardium’s mechanical response. To assess regional differences, we excised tissue specimens from the conus and sinus regions. The RVFW myocardium was found to be consistently anisotropic, with a greater stiffness along the preferred (or averaged) fiber direction. The anisotropy in the conus region was more pronounced than in the sinus region. A comparison with studies of left ventricle (LV) midwall myocardium revealed that, 1) the fiber direction stiffnesses are greater in the RVFW than in the LV, 2) the degree of anisotropy is greater in the RVFW than in the LV.

A Comparative Study of the Main Pulmonary Artery and Ascending Aorta Biomechanical Behavior

2011 ◽  
Author(s):  
Bahar Fata ◽  
Elena Galdi ◽  
Michael S. Sacks
Keyword(s):  
Pulmonary Artery ◽  
Mechanical Behavior ◽  
Ductus Arteriosus ◽  
Main Pulmonary Artery ◽  
Blood Flow Rate ◽  
Biomechanical Properties ◽  
Ascending Aorta ◽  
External Diameter ◽  
Blood Flows ◽  
Biomechanical Behavior

During the prenatal period a state of physiologic pulmonary hypertension exists due to the equalization of pressures by the patent ductus arteriosus, resulting in similar wall thickness of the ascending aorta (AA) and main pulmonary artery (MPA). After birth, as the ductus arteriosus closes and pulmonary arterial pressure decreases, attenuation of medial smooth muscle occurs such that the ratio of medial thickness to external diameter decreases from about 25% in fetuses to less than 10% in infants 3 to 6 months of age. After the first year of life, thickness of the MPA is normally less than half that of the adjacent ascending aorta, although the diameters of the two great arteries remain the same relative to one another [1]. During homeostatic conditions, the total pulmonary and systemic blood flows are essentially identical. In spite of their comparable blood flow rate and common embryologic origin, the anatomic characteristics of these two segments of the cardiovascular system differ substantially [2]. Futhremore, both these arteries are affected by many congenital abnormalities and also are subject to hypertension. Knowledge of the normal biomechanical properties of these great arteries is important for surgical treamtment, angioplasty, and tissue engineering. It can also provide insight into the disease processes and is a prerequisite to the study of mechanical behavior during disease conditions. In this study we characterized the biaxial mechanical behavior of both arteries as a function of location, which has not been previously performed in the pulmonary trunk.

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