Effects of osmotic pressure in the extracellular matrix on tissue deformation

2006 ◽  
Vol 364 (1843) ◽  
pp. 1407-1422 ◽  
Author(s):  
Y Lu ◽  
K.H Parker ◽  
W Wang
Keyword(s):  
Extracellular Matrix ◽  
Osmotic Pressure ◽  
Soft Tissues ◽  
Moving Boundary ◽  
Analytic Solutions ◽  
Tissue Deformation ◽  
Large Molecules ◽  
Tissue Integrity ◽  
External Pressures ◽  
Dynamic Loading Conditions

In soft tissues, large molecules such as proteoglycans trapped in the extracellular matrix (ECM) generate high levels of osmotic pressure to counter-balance external pressures. The semi-permeable matrix and fixed negative charges on these molecules serve to promote the swelling of tissues when there is an imbalance of molecular concentrations. Structural molecules, such as collagen fibres, form a network of stretch-resistant matrix, which prevents tissue from over-swelling and keeps tissue integrity. However, collagen makes little contribution to load bearing; the osmotic pressure in the ECM is the main contributor balancing external pressures. Although there have been a number of studies on tissue deformation, there is no rigorous analysis focusing on the contribution of the osmotic pressure in the ECM on the viscoelastic behaviour of soft tissues. Furthermore, most previous works were carried out based on the assumption of infinitesimal deformation, whereas tissue deformation is finite under physiological conditions. In the current study, a simplified mathematical model is proposed. Analytic solutions for solute distribution in the ECM and the free-moving boundary were derived by solving integro-differential equations under constant and dynamic loading conditions. Osmotic pressure in the ECM is found to contribute significantly to the viscoelastic characteristics of soft tissues during their deformation.

Deformation of the Extracellular Matrix Due to Osmotic Pressure in Cartilaginous Tissues

2010 ◽  
Vol 93-94 ◽  
pp. 243-246
Author(s):  
Boonyong Punantapong
Keyword(s):  
Extracellular Matrix ◽  
Osmotic Pressure ◽  
Preferential Flow ◽  
Soft Tissues ◽  
Analytic Solutions ◽  
Tissue Integrity ◽  
Cartilaginous Tissues ◽  
External Pressures ◽  
Field Fluctuations ◽  
Constrained Deformation

This study is to characterize and estimate preferential flow and solute transport in soft tissue. In soft tissues, large molecules such as proteoglycans trapped in the extracellular matrix generate high levels of osmotic pressure to counter balance external pressures. The semi-permeable matrix and fixed negative charges on these molecules serve to promote the swelling and collapse behaviour of cartilaginous tissues when there is an imbalance of molecular concentrations. At the same time, the collagen fibres were a network of stretch-resistant matrix, which prevents tissue from over-swelling and keeps tissue integrity. Therefore, a simplified mathematical model is proposed, and implemented in the finite element method. Analytic solutions for solute distribution in the extracellular matrix were derived by solving under loading conditions. The results were found that the estimate with field fluctuations led to the numerical results in most cases, and significant differences were only found under conditions of highly constrained deformation.

A Multiscale Approach to Modeling the Passive Mechanical Contribution of Cells in Tissues

2013 ◽  
Author(s):  
Victor K. Lai ◽  
Mohammad F. Hadi ◽  
Robert T. Tranquillo ◽  
Victor H. Barocas
Keyword(s):  
Extracellular Matrix ◽  
Soft Tissues ◽  
Multiscale Model ◽  
Tissue Mechanics ◽  
Multiscale Approach ◽  
Cellular Solids ◽  
Comprehensive Model ◽  
Modeling Framework ◽  
Tissue Biomechanics ◽  
Tensegrity Model

In addition to their obvious biological roles in tissue function, cells often play a significant mechanical role through a combination of passive and active behaviors. Phenomenological and continuum modeling approaches to understand tissue biomechanics have included improved constitutive laws that incorporate anisotropy in the extracellular matrix (ECM) and/or cellular phenomenon, e.g, [1]. The lack of microstructural detail in these models, however, limits their ability to explore the respective contributions and interactions between different components within a tissue. In contrast, structural approaches attempt to understand tissue biomechanics by incorporating microstructural details directly into the model, e.g., the tensegrity model [2], cellular solids models [3], or biopolymer models [4]. Research in our group focuses on developing a comprehensive model to predict the mechanical behavior of soft tissues via a multiscale approach, a technique that allows integration of the microstructural details of different components into the modeling framework. A significant gap in our previous models, however, is the absence of cells. The current work represents an improvement of the multiscale model via the addition of cells, and investigates the passive mechanical contribution of cells to overall tissue mechanics.

Development and Verification of a Dynamic TKR Model

2002 ◽  
Author(s):  
Jason P. Halloran ◽  
Anthony J. Petrella ◽  
Paul J. Rullkoetter
Keyword(s):  
Finite Element ◽  
Contact Mechanics ◽  
Dynamic Loading ◽  
Soft Tissues ◽  
Dynamic Models ◽  
Total Joint Replacement ◽  
Fe Model ◽  
Loading Conditions ◽  
Dynamic Loading Conditions

The success of current total knee replacement (TKR) devices is contingent on the kinematics and contact mechanics during in vivo activity. Indicators of potential clinical performance of total joint replacement devices include contact stress and area due to articulations, and tibio-femoral and patello-femoral kinematics. An effective way of evaluating these parameters during the design phase or before clinical use is via computationally efficient computer models. Previous finite element (FE) knee models have generally been used to determine contact stresses and/or areas during static or quasi-static loading conditions. The majority of knee models intended to predict relative kinematics have not been able to determine contact mechanics simultaneously. Recently, however, explicit dynamic finite element methods have been used to develop dynamic models of TKR able to efficiently determine joint and contact mechanics during dynamic loading conditions [1,2]. The objective of this research was to develop and validate an explicit FE model of a TKR which includes tibio-femoral and patello-femoral articulations and surrounding soft tissues. The six degree-of-freedom kinematics, kinetics and polyethylene contact mechanics during dynamic loading conditions were then predicted during gait simulation.

Osmo-inelastic response of the intervertebral disc

2019 ◽  
Vol 233 (3) ◽  
pp. 332-341 ◽  
Author(s):  
Amil Derrouiche ◽  
Ameni Zaouali ◽  
Fahmi Zaïri ◽  
Jewan Ismail ◽  
Makram Chaabane ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Intervertebral Disc ◽  
Soft Tissues ◽  
Rate Dependency ◽  
Fluid Exchange ◽  
Inelastic Response ◽  
Loading Rates ◽  
Inelastic Behaviour ◽  
Tension And Compression ◽  
Chemical Conditions

The intervertebral disc exhibits a complex inelastic response characterized by relaxation, hysteresis during cyclic loading and rate dependency. All these inelastic phenomena depend on osmotic interactions between disc tissues and their surrounding chemical environment. Coupling between osmotic and inelastic effects is not fully understood, so this article aimed to study the influence of chemical conditions on the inelastic behaviour of the intervertebral disc in response to different modes of loading. A total of 18 non-frozen ‘motion segments’ (two vertebrae and the intervening soft tissues) were dissected from the cervical spines of mature sheep. The motion segments were loaded in tension, compression and torsion at various loading rates and saline concentrations. Analysis of variance showed that saline concentration significantly influenced inelastic effects in tension and especially in compression (p < 0.05), but not in torsion. Opposite effects were seen in tension and compression. An interpretation of the underlying osmo-inelastic mechanisms is proposed in which two sources of inelastic effects are identified, that is, extracellular matrix rearrangements and fluid exchange created by osmosis.

Probing Micromechanical Properties of the Extracellular Matrix of Soft Tissues by Atomic Force Microscopy

2016 ◽  
Vol 232 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Ignasi Jorba ◽  
Juan J. Uriarte ◽  
Noelia Campillo ◽  
Ramon Farré ◽  
Daniel Navajas
Keyword(s):  
Extracellular Matrix ◽  
Atomic Force Microscopy ◽  
Soft Tissues ◽  
Force Microscopy ◽  
Micromechanical Properties ◽  
Atomic Force

scholarly journals The same but different: cell intercalation as a driver of tissue deformation and fluidity

2018 ◽  
Vol 373 (1759) ◽  
pp. 20170328 ◽  
Author(s):  
Robert J. Tetley ◽  
Yanlan Mao
Keyword(s):  
Cell Adhesion ◽  
Large Scale ◽  
Computational Models ◽  
Driving Forces ◽  
Tissue Deformation ◽  
Animal Development ◽  
Tissue Integrity ◽  
Epithelial Tissues ◽  
Tissue Deformations ◽  
Cell Intercalation

The ability of cells to exchange neighbours, termed intercalation, is a key feature of epithelial tissues. Intercalation is predominantly associated with tissue deformations that drive morphogenesis. More recently, however, intercalation that is not associated with large-scale tissue deformations has been described both during animal development and in mature epithelial tissues. This latter form of intercalation appears to contribute to an emerging phenomenon that we refer to as tissue fluidity—the ability of cells to exchange neighbours without changing the overall dimensions of the tissue. Here, we discuss the contribution of junctional dynamics to intercalation governing both morphogenesis and tissue fluidity. In particular, we focus on the relative roles of junctional contractility and cell–cell adhesion as the driving forces behind intercalation. These two contributors to junctional mechanics can be used to simulate cellular intercalation in mechanical computational models, to test how junctional cell behaviours might regulate tissue fluidity and contribute to the maintenance of tissue integrity and the onset of disease. This article is part of the Theo Murphy meeting issue ‘Mechanics of development’.

Role of extravascular protein in capillary-tissue fluid exchange

1978 ◽  
Vol 234 (1) ◽  
pp. H52-H58
Author(s):  
E. P. Salathe ◽  
R. Venkataraman
Keyword(s):  
Mathematical Model ◽  
Perturbation Theory ◽  
Osmotic Pressure ◽  
Analytic Solutions ◽  
Tissue Fluid ◽  
Fluid Exchange ◽  
Numerical Examples ◽  
Pathological Conditions ◽  
And Diffusion

A mathematical model of capillary-tissue fluid exchange is presented. The effect of variation in plasma and interstitial osmotic pressure that occurs as a result of convection and diffusion of protein is examined. Analytic solutions to the resulting equations are obtained by using the methods of perturbation theory. It is found that fluid exchange can significantly alter the pericapillary interstitial osmotic pressure, reducing both filtration and reabsorption. Variation in plasma osmotic pressure is important only for certain pathological conditions in which excessive filtration occurs. Specific numerical examples are presented which show quantitatively the extent of these effects for various normal and pathological conditions of physiological interest.

scholarly journals Extracellular Matrix Stiffness and Composition Regulate the Myofibroblast Differentiation of Vaginal Fibroblasts

2020 ◽  
Vol 21 (13) ◽  
pp. 4762
Author(s):  
Alejandra M. Ruiz-Zapata ◽  
Andrea Heinz ◽  
Manon H. Kerkhof ◽  
Cindy van de Westerlo-van Rijt ◽  
Christian E. H. Schmelzer ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Soft Tissues ◽  
Smooth Muscle Actin ◽  
Pelvic Organ ◽  
Preliminary Evidence ◽  
Myofibroblast Differentiation ◽  
Matrix Stiffness ◽  
Gene Expressions ◽  
Vaginal Reconstruction ◽  
Vaginal Fibroblasts

Fibroblast to myofibroblast differentiation is a key feature of wound-healing in soft tissues, including the vagina. Vaginal fibroblasts maintain the integrity of the vaginal wall tissues, essential to keep pelvic organs in place and avoid pelvic organ prolapse (POP). The micro-environment of vaginal tissues in POP patients is stiffer and has different extracellular matrix (ECM) composition than healthy vaginal tissues. In this study, we employed a series of matrices with known stiffnesses, as well as vaginal ECMs, in combination with vaginal fibroblasts from POP and healthy tissues to investigate how matrix stiffness and composition regulate myofibroblast differentiation in vaginal fibroblasts. Stiffness was positively correlated to production of α-smooth muscle actin (α-SMA). Vaginal ECMs induced myofibroblast differentiation as both α-SMA and collagen gene expressions were increased. This differentiation was more pronounced in cells seeded on POP-ECMs that were stiffer than those derived from healthy tissues and had higher collagen and elastin protein content. We showed that stiffness and ECM content regulate vaginal myofibroblast differentiation. We provide preliminary evidence that vaginal fibroblasts might recognize POP-ECMs as scar tissues that need to be remodeled. This is fundamentally important for tissue repair, and provides a rational basis for POP disease modelling and therapeutic innovations in vaginal reconstruction.

A tale of 2 tissues: the overlapping role of scleraxis in tendons and the heart

2014 ◽  
Vol 92 (9) ◽  
pp. 707-712 ◽  
Author(s):  
Michael P. Czubryt
Keyword(s):  
Extracellular Matrix ◽  
Cell Types ◽  
Response Mechanism ◽  
Growth And Remodeling ◽  
Tissue Integrity ◽  
Common Response ◽  
The Face ◽  
Physical Forces ◽  
Inherent Nature

Tissue integrity in the face of external physical forces requires the production of a strong extracellular matrix (ECM) composed primarily of the protein collagen. Tendons and the heart both withstand large and changing physical forces, and emerging evidence suggests that the transcription factor scleraxis plays a central role in responding to these forces by directly regulating the production of ECM components and (or) by determining the fate of matrix-producing cell types. Thus, despite the highly disparate inherent nature of these tissues, a common response mechanism may exist to govern the development, growth, and remodeling of the ECM in response to external force.

scholarly journals A moving boundary problem for the Stokes equations involving osmosis: Variational modelling and short-time well-posedness

2015 ◽  
Vol 27 (4) ◽  
pp. 647-666
Author(s):  
FRIEDRICH LIPPOTH ◽  
MARK A. PELETIER ◽  
GEORG PROKERT
Keyword(s):  
Surface Tension ◽  
Boundary Problem ◽  
Osmotic Pressure ◽  
Moving Boundary ◽  
Stokes Equations ◽  
Semipermeable Membrane ◽  
Moving Boundary Problem ◽  
Classical Solutions ◽  
Well Posedness ◽  
Short Time

Within the framework of variational modelling we derive a one-phase moving boundary problem describing the motion of a semipermeable membrane enclosing a viscous liquid, driven by osmotic pressure and surface tension of the membrane. For this problem we prove the existence of classical solutions for a short-time.

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