A theoretical study on the elastic deformation of cellular phase and creation of necrosis due to the convection reaction process inside a spherical tumor

2016 ◽  
Vol 09 (06) ◽  
pp. 1650095 ◽  
Author(s):  
Bibaswan Dey ◽  
G. P. Raja Sekhar
Keyword(s):  
Fluid Flow ◽  
Fluid Motion ◽  
Mixture Theory ◽  
Biological Tissues ◽  
Interstitial Space ◽  
Interstitial Fluid Flow ◽  
Nutrient Distribution ◽  
Drug Molecules ◽  
Spherically Symmetry ◽  
Spherical Tumor

Several biological processes, such as convective nutrient transport and convective drug delivery in biological tissues involves the transvascular and interstitial movement of biofluids. This work addresses transvascular and interstitial transport of nutrient inside a spherical tumor. Most of the biological tissues behave like deformable porous material and show mechanical behavior towards the fluid motion, due to the fact, that the forces like the drag, which is associated with fluid flow may compress the tissue material. On the macroscopic level, transport of solutes like nutrients, drug molecules, etc. within the tumor interstitial space is modeled. The hydrodynamic problem is treated with biphasic mixture theory under steady state and spherically symmetry situation. The transvascular transport of nutrient is modeled with the modified Sterling’s equation. The present model describes the overall nutrient distribution and predicts various criteria for the necrosis formation inside the tumor. Present study justifies that the parameters, which controls the nutrient supply to the tumor interstitial space through the blood vessel network inside the tumor, competes with reversible nutrient consumption kinetics of the tumor cells. This study also finds the role of some of those parameters on the deformation of cellular phase of the tumor as a consequence of interstitial fluid flow.

Drug Transport by Fluid Motion

Drug Delivery ◽  
2001 ◽  
Author(s):  
W. Mark Saltzman
Keyword(s):  
Drug Transport ◽  
Interstitial Fluid ◽  
Fluid Motion ◽  
Convective Transport ◽  
Interstitial Space ◽  
The Body ◽  
Cross Sectional ◽  
Drug Molecules ◽  
Molecular Movement ◽  
The Brain

The rate of molecular movement by diffusion decreases dramatically with distance, and is generally inadequate for transport over distances greater than 100 μm. The movement of molecules over distances greater than 100 μm occurs in specialized compartments in the body: blood circulates through arteries and veins; interstitial fluid collects in lymphatic vessels before returning to the blood; cerebrospinal fluid (CSF) percolates through the central nervous system (CNS) in the brain ventricles and subarachnoid space. In these systems, molecules move primarily by bulk flow, or convection. Diffusive transport is driven by differences in concentration; convective transport is driven by differences in hydrostatic and osmotic pressure. This chapter introduces the principles of drug distribution by pressure-driven transport. The elaborate network of arteries, capillaries, and veins that carry blood throughout the body are described first in this chapter. Hydrostatic pressure within the blood vasculature drives fluid through the vessel wall (recall Equation 5-28) and into the extravascular space of tissues. Fluid flow through the interstitial space is not well understood, although the importance of interstitial flows in moving drug molecules through tissue is beginning to be appreciated. Engineering approaches for analyzing fluid flows in the interstitium are described in the second section of the chapter. Finally, the specialized systems for returning interstitial fluid to the blood are essential for clearance of molecules from the interstitial space; therefore, the chapter also provides a description of the dynamics of lymph flow in the periphery and CSF production and circulation in the brain. Our bodies appear, from the outside, to be solid masses that are slow to change, but, just beneath the surface, is a torrent of fluid motion. Blood moves at high velocity throughout the body within an interconnected and highly branched network of vessels. The cross-sectional area changes significantly along the network, and blood flow to the periphery emerges from the heart within a single vessel, which branches and rebranches to distribute blood to every tissue and organ.

scholarly journals On the characterization of interstitial fluid flow in the skeletal muscle endomysium

2020 ◽  
Vol 102 ◽  
pp. 103504 ◽  
Author(s):  
Qiuyun Wang ◽  
Shaopeng Pei ◽  
X. Lucas Lu ◽  
Liyun Wang ◽  
Qianhong Wu
Keyword(s):  
Skeletal Muscle ◽  
Fluid Flow ◽  
Interstitial Fluid ◽  
Interstitial Fluid Flow

Continuum Thermodynamics of Constrained Reactive Mixtures

2021 ◽  
Author(s):  
Gerard A. Ateshian ◽  
Brandon Zimmerman
Keyword(s):  
Heat Supply ◽  
Damage Mechanics ◽  
Reactive Power ◽  
Mixture Theory ◽  
Biological Tissues ◽  
Heat Of Reaction ◽  
Chemical Potentials ◽  
Ideal Gases ◽  
Reactive Processes ◽  
Energy Of Formation

Abstract Mixture theory models continua consisting of multiple constituents with independent motions. In constrained mixtures all constituents share the same velocity but they may have different reference configurations. The theory of constrained reactive mixtures was formulated to analyze growth and remodeling in living biological tissues. It can also reproduce and extend classical frameworks of damage mechanics and viscoelasticity under isothermal conditions, when modeling bonds that can break and reform. This study focuses on establishing the thermodynamic foundations of constrained reactive mixtures under more general conditions, for arbitrary reactive processes where temperature varies in time and space. By incorporating general expressions for reaction kinetics, it is shown that the residual dissipation statement of the Clausius-Duhem inequality must include a reactive power density, while the axiom of energy balance must include a reactive heat supply density. Both of these functions are proportional to the molar production rate of a reaction, and they depend on the chemical potentials of the mixture constituents. We present novel formulas for the classical thermodynamic concepts of energy of formation and heat of reaction, making it possible to evaluate the heat supply generated by reactive processes from the knowledge of the specific free energy of mixture constituents as well as the reaction rate. We illustrate these novel concepts with mixtures of ideal gases, and isothermal reactive damage mechanics and viscoelasticity, as well as reactive thermoelasticity. This framework facilitates the analysis of reactive tissue biomechanics and physiological and biomedical engineering processes where temperature variations cannot be neglected.

scholarly journals Interstitial flow promotes macrophage polarization toward an M2 phenotype

2018 ◽  
Vol 29 (16) ◽  
pp. 1927-1940 ◽  
Author(s):  
Ran Li ◽  
Jean Carlos Serrano ◽  
Hao Xing ◽  
Tara A. Lee ◽  
Hesham Azizgolshani ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Tumor Microenvironment ◽  
Tumor Progression ◽  
Cancer Cell ◽  
Interstitial Fluid ◽  
Macrophage Polarization ◽  
Interstitial Flow ◽  
Interstitial Fluid Flow ◽  
M2 Polarization ◽  
Tumor Tissues

Tumor tissues are characterized by an elevated interstitial fluid flow from the tumor to the surrounding stroma. Macrophages in the tumor microenvironment are key contributors to tumor progression. While it is well established that chemical stimuli within the tumor tissues can alter macrophage behaviors, the effects of mechanical stimuli, especially the flow of interstitial fluid in the tumor microenvironment, on macrophage phenotypes have not been explored. Here, we used three-dimensional biomimetic models to reveal that macrophages can sense and respond to pathophysiological levels of interstitial fluid flow reported in tumors (∼3 µm/s). Specifically, interstitial flow (IF) polarizes macrophages toward an M2-like phenotype via integrin/Src-mediated mechanotransduction pathways involving STAT3/6. Consistent with this flow-induced M2 polarization, macrophages treated with IF migrate faster and have an enhanced ability to promote cancer cell migration. Moreover, IF directs macrophages to migrate against the flow. Since IF emanates from the tumor to the surrounding stromal tissues, our results suggest that IF could not only induce M2 polarization of macrophages but also recruit these M2 macrophages toward the tumor masses, contributing to cancer cell invasion and tumor progression. Collectively, our study reveals that IF could be a critical regulator of tumor immune environment.

scholarly journals Mathematical analysis of hydrodynamics and tissue deformation inside an isolated solid tumor

2018 ◽  
Vol 45 (2) ◽  
pp. 253-278 ◽  
Author(s):  
Meraj Alam ◽  
Bibaswan Dey ◽  
Sekhar Raja
Keyword(s):  
Solid Tumor ◽  
Solid Phase ◽  
Fluid Motion ◽  
Extracellular Fluid ◽  
Mixture Theory ◽  
Coupled System ◽  
Weak Sense ◽  
Governing Equations ◽  
One Dimensional ◽  
2D And 3D

In this article, we present a biphasic mixture theory based mathematical model for the hydrodynamics of interstitial fluid motion and mechanical behavior of the solid phase inside a solid tumor. The tumor tissue considered here is an isolated deformable biological medium. The solid phase of the tumor is constituted by vasculature, tumor cells, and extracellular matrix, which are wet by a physiological extracellular fluid. Since the tumor is deformable in nature, the mass and momentum equations for both the phases are presented. The momentum equations are coupled due to the interaction (or drag) force term. These governing equations reduce to a one-way coupled system under the assumption of infinitesimal deformation of the solid phase. The well-posedness of this model is shown in the weak sense by using the inf-sup (Babuska?Brezzi) condition and Lax?Milgram theorem in 2D and 3D. Further, we discuss a one-dimensional spherical symmetry model and present some results on the stress fields and energy of the system based on ??2 and Sobolev norms. We discuss the so-called phenomena of ?necrosis? inside a solid tumor using the energy of the system.

Effects of focused shock waves on biological tissues: Cavitation in the prefocal region and the fluid flow in the focal region

Shock Waves ◽  
1992 ◽  
pp. 41-48
Author(s):  
M. Kuwahara ◽  
N. Ioritani ◽  
T. Saito ◽  
S. Hoshi ◽  
S. Shirai ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Shock Waves ◽  
Biological Tissues ◽  
Focal Region
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