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Georgia Tech
1.
Miller, Ryan Michael.
Continuum Modeling of Liquid-Solid Suspensions for Nonviscometric Flows.
Degree: PhD, Chemical Engineering, 2004, Georgia Tech
URL: http://hdl.handle.net/1853/4864
► A suspension flow model based on the "suspension balance" approach has been developed. This work modifies the model to allow the solution of suspension flows…
(more)
▼ A suspension flow model based on the "suspension balance" approach has been developed. This work modifies the model to allow the solution of suspension flows under general flow conditions. This requires the development of a frame-invariant constitutive model for the particle stress which can take into account the spatially-varying local kinematic conditions. The mass and momentum balances for the bulk suspension
and particle phase are solved numerically using a finite volume method. The particle stress is based upon the computed rate of strain and the local kinematic conditions. A nonlocal stress
contribution corrects the continuum approximation of the particle phase for finite particle size effects. Local kinematic conditions are accounted through the local ratio of rotation to extension in the flow field. The coordinates for the stress definition are the local principal axes of the rate of strain field.
The developed model is applied to a range of problems. (i) Axially-developing conduit flows are computed using both the full two-dimensional solution and the more computationally
efficient "marching" method. The model predictions are compared to experimental results for cross-stream particle concentration profiles and axial development lengths. (ii) Model
predictions are compared to experiments for wide-gap circular Couette flow of a concentrated suspension in a shear-thinning liquid. With minor modification, the suspension flow model predicts the major trends and results observed in this flow. (iii) Comparisons are made to experiments for an axisymmetric contraction-expansion. Model predictions for a two-dimensional planar contraction flow test the influence of model formulation. The variation of the magnitude of an isotropic particle normal stress with local kinematic conditions and anisotropy in the
in-plane normal stresses are both explored. The formulation of the particle phase stress is found to have significant effects on the solid fraction and velocity. (iv) Finally, for a rectangular
piston-driven flow and an obstructed channel flow, a "computational suspension dynamics" study explores the effect of particle migration on the bulk flow field, system pressure drop
and particle phase composition.
Advisors/Committee Members: Forney, Larry (Committee Co-Chair), Morris, Jeffrey F. (Committee Co-Chair), Carr, Wallace W. (Committee Member), Koros, William J. (Committee Member), Wick, Timothy M. (Committee Member), Yiacoumi, Sotira Z. (Committee Member), Yoda, Minami (Committee Member).
Subjects/Keywords: Two-phase flow; Suspension flow; Frame-invariant rheology; Finite volume method; Shear-induced migration; Suspension balance model; Shear flow; Finite volume method; Two-phase flow; Rheology; Continuum mechanics
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APA (6th Edition):
Miller, R. M. (2004). Continuum Modeling of Liquid-Solid Suspensions for Nonviscometric Flows. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/4864
Chicago Manual of Style (16th Edition):
Miller, Ryan Michael. “Continuum Modeling of Liquid-Solid Suspensions for Nonviscometric Flows.” 2004. Doctoral Dissertation, Georgia Tech. Accessed April 13, 2021.
http://hdl.handle.net/1853/4864.
MLA Handbook (7th Edition):
Miller, Ryan Michael. “Continuum Modeling of Liquid-Solid Suspensions for Nonviscometric Flows.” 2004. Web. 13 Apr 2021.
Vancouver:
Miller RM. Continuum Modeling of Liquid-Solid Suspensions for Nonviscometric Flows. [Internet] [Doctoral dissertation]. Georgia Tech; 2004. [cited 2021 Apr 13].
Available from: http://hdl.handle.net/1853/4864.
Council of Science Editors:
Miller RM. Continuum Modeling of Liquid-Solid Suspensions for Nonviscometric Flows. [Doctoral Dissertation]. Georgia Tech; 2004. Available from: http://hdl.handle.net/1853/4864

Georgia Tech
2.
Xing, Yun.
Effects of Mechanical Forces on the Biological Properties of Porcine Aortic Valve Leaflets.
Degree: PhD, Bioengineering, 2005, Georgia Tech
URL: http://hdl.handle.net/1853/6828
► Cardiac valves are dynamic, sophisticated structures which interact closely with the surrounding hemodynamic environment. Altered mechanical stresses, including pressure, shear and bending stresses, are believed…
(more)
▼ Cardiac valves are dynamic, sophisticated structures which interact closely with the surrounding hemodynamic environment. Altered mechanical stresses, including pressure, shear and bending stresses, are believed to cause changes in valve biology, but the cellular and molecular events involved in these processes are not well characterized. Therefore, the overall goal of this project is to determine the effects of pressure and shear stress on porcine aortic valve leaflets biology.
Results from the pressure study showed that elevated constant pressure (140 and 170 mmHg) causes significant increases in collagen synthesis. The increases were 37.5% and 90% for 140 and 170 mmHg, respectively. No significant differences in DNA and sGAG synthesis were observed under constant pressure. In the cyclic pressure study, the effects of both pressure magnitude and pulse frequency were studied. With the frequency fixed at 1.167 Hz, collagen and sGAG synthesis increased proportionally with mean pressure level. At a fixed pressure level (80-120 mmHg), collagen and sGAG synthesis were slightly increased by 25% and 14% at 0.5 Hz, respectively. DNA synthesis was significantly increased by 72% at 2 Hz. An experiment combining high magnitude (150-190 mmHg) and high frequency (2 Hz) demonstrated significant increases in collagen and sGAG synthesis (collagen: 74%, sGAG: 56%), but no significant changes in cell proliferation.
Shear levels ranging from 1 to 80 dyne/cm2 were studied. Scanning electron microscopy results indicated that 48 hrs exposure to shear stress did not alter the circumferential alignment of endothelial cells. Collagen synthesis was significantly enhanced at 9 and 25 dyne/cm2, but not different from static controls under other shear conditions. Leaflets denuded of the endothelium were exposed to identical shear stress and showed very different responses. Collagen synthesis was not affected at any shear levels, but sGAG content was increased at shear of 9, 25 and 40 dyne/cm2.
Further studies showed that the increases in collagen synthesis under pressure or shear stress was concurrent with a decline in the expression and activities of cathepsins L and S. This converse relationship between collagen synthesis and cathepsin activity indicated that cathepsins might be involved in valvular ECM remodeling.
Advisors/Committee Members: Yoganathan, Ajit (Committee Chair), Hilbert, Steve (Committee Member), Jo, Hanjoong (Committee Member), Nerem, Robert (Committee Member), Wick, Timothy (Committee Member).
Subjects/Keywords: Heart valves; Mechanical forces; Tissue engineering; Shear flow; Strains and stresses; Heart valves; Hemodynamics
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
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APA (6th Edition):
Xing, Y. (2005). Effects of Mechanical Forces on the Biological Properties of Porcine Aortic Valve Leaflets. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/6828
Chicago Manual of Style (16th Edition):
Xing, Yun. “Effects of Mechanical Forces on the Biological Properties of Porcine Aortic Valve Leaflets.” 2005. Doctoral Dissertation, Georgia Tech. Accessed April 13, 2021.
http://hdl.handle.net/1853/6828.
MLA Handbook (7th Edition):
Xing, Yun. “Effects of Mechanical Forces on the Biological Properties of Porcine Aortic Valve Leaflets.” 2005. Web. 13 Apr 2021.
Vancouver:
Xing Y. Effects of Mechanical Forces on the Biological Properties of Porcine Aortic Valve Leaflets. [Internet] [Doctoral dissertation]. Georgia Tech; 2005. [cited 2021 Apr 13].
Available from: http://hdl.handle.net/1853/6828.
Council of Science Editors:
Xing Y. Effects of Mechanical Forces on the Biological Properties of Porcine Aortic Valve Leaflets. [Doctoral Dissertation]. Georgia Tech; 2005. Available from: http://hdl.handle.net/1853/6828

Georgia Tech
3.
Brown, Lola A.
The Effects of Sickle Erythrocytes on Endothelial Permeability.
Degree: MS, Biomedical Engineering, 2005, Georgia Tech
URL: http://hdl.handle.net/1853/6960
► Sickle cell anemia is a hematological disorder that is caused by a single point mutation in the beta-globin chain of hemoglobin. It results in several…
(more)
▼ Sickle cell anemia is a hematological disorder that is caused by a single point mutation in the beta-globin chain of hemoglobin. It results in several complications related to the small and large vessels in patients with the disease. Large vessel complications include cerebral infarcts, which are observed in children under ten years old. The mechanism behind this complication is not completely understood.
It is the goal of this project to begin to understand the role sickle erythrocytes may play in causing endothelial dysfunction as a precursor to sickle related complications. The hypothesis of this work is that exposure of large vessel endothelium to sickle erythrocytes causes an increase in endothelial permeability through loosening of adherens junctions.
In the first goal of this work, bovine aortic endothelial cells (BAECs) are grown on coverslips and exposed to sickle erythrocytes for 5 minutes and either immediately fixed or incubated in 30 minutes and then fixed. Immunofluorescent studies labeling VE cadherin show changes in VE cadherin dynamics, suggesting sickle erythrocytes may be involved in this observation.
Next, BAECs were grown on transwell inserts and exposed to sickle erythrocytes for 5 minutes. The erythrocytes are washed off and the BAEC are incubated with 10,000 MW dextran conjugated to lucifer yellow or FITC-BSA or to determine BAEC permeability. When dextran is used as the test molecule, endothelial permeability did not show a significant change from baseline. However, when BSA is used as the test molecule, increases in endothelial permeability are observed. Explanations into the differences between the transport mechanisms of the two molecules are discussed.
These experiments show changes in VE cadherin localization due to sickle erythrocyte exposure. This may cause increases in endothelial permeability and an experimental model and preliminary studies are performed. This study provides potential mechanisms to explain the changes in VE cadherin localization and provide suggestions for further studies to test the effect of sickle erythrocytes on endothelial permeability. This work provides a strong foundation for continuing studies on the effects of sickle erythrocytes on endothelial dysfunction within the confines of sickle related complications.
Advisors/Committee Members: Wick, Timothy (Committee Chair), Barabino, Gilda (Committee Co-Chair), Eckman, James (Committee Member), Nerem, Robert (Committee Member).
Subjects/Keywords: Permeability coefficient; VE cadherin; Stroke; Endothelial cells; Sickle cell anemia
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
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APA (6th Edition):
Brown, L. A. (2005). The Effects of Sickle Erythrocytes on Endothelial Permeability. (Masters Thesis). Georgia Tech. Retrieved from http://hdl.handle.net/1853/6960
Chicago Manual of Style (16th Edition):
Brown, Lola A. “The Effects of Sickle Erythrocytes on Endothelial Permeability.” 2005. Masters Thesis, Georgia Tech. Accessed April 13, 2021.
http://hdl.handle.net/1853/6960.
MLA Handbook (7th Edition):
Brown, Lola A. “The Effects of Sickle Erythrocytes on Endothelial Permeability.” 2005. Web. 13 Apr 2021.
Vancouver:
Brown LA. The Effects of Sickle Erythrocytes on Endothelial Permeability. [Internet] [Masters thesis]. Georgia Tech; 2005. [cited 2021 Apr 13].
Available from: http://hdl.handle.net/1853/6960.
Council of Science Editors:
Brown LA. The Effects of Sickle Erythrocytes on Endothelial Permeability. [Masters Thesis]. Georgia Tech; 2005. Available from: http://hdl.handle.net/1853/6960
4.
Kinney, Ramsey Christian.
The role of sexual dimorphism in cartilage tissue regeneration.
Degree: PhD, Biomedical Engineering, 2008, Georgia Tech
URL: http://hdl.handle.net/1853/28225
► Osteoarthritis is a degenerative joint disease characterized by progressive erosion of the articular cartilage. Epidemiological studies have established a relationship between osteoarthritis and menopause suggesting…
(more)
▼ Osteoarthritis is a degenerative joint disease characterized by progressive erosion of the articular cartilage. Epidemiological studies have established a relationship between osteoarthritis and menopause suggesting that estrogen may be important in the development of cartilage regeneration therapies. The overall goal of this research project was to advance the field of cartilage tissue regeneration by investigating the role of 17 ß -estradiol (E2), an active estrogen metabolite, on the chondrocyte phenotype. The central hypothesis was that E2 plays an important and sex-specific role in regulating chondrogenesis. Specific Aim-1 focused on establishing and characterizing a primary human articular chondrocyte (HAC) cell source, and then examining the response of the cells in culture to E2. It was demonstrated that the response of HACs to E2 treatment was sex-specific despite both male and females cells expressing estrogen receptors. Female HACs showed changes in proliferation, matrix production, and differentiation while male cells did not. In addition, the female response was regulated through a rapid membrane signaling pathway mediated by protein kinase C. Specific Aim-2 involved establishing an ovariectomized animal model to investigate the effects of E2 on orthopaedic tissue implants. Human demineralized bone matrix (DBM) was implanted intramuscularly into female nude mice and rats. Ovariectomy was shown to reduce the ability of DBM to induce the formation of cartilage and bone tissue. Moreover, the inductive properties of DBM were reestablished with subcutaneous E2 supplementation. Specific Aim-3 entailed developing and characterizing a microencapsulation method for in vitro culture and in vivo delivery of chondrocytes to study the effects of E2 on chondrogenesis. Rat growth plate chondrocytes and HACs were microencapsulated in alginate using an extrusion method in conjunction with high electrostatic potential. Chondrocytes maintained their phenotype in alginate suspension but were unable to form cartilage tissue when implanted into our animal model. Further optimization of the system is required before the role of E2 on chondrogenesis of tissue engineered constructs can be determined. In summary, our results suggest that the successful production of tissue engineered therapies will likely depend on understanding and manipulating the actions of sex hormones in both the in vitro and in vivo environment.
Advisors/Committee Members: Boyan, Barbara (Committee Chair), Bonassar, Lawrence (Committee Member), Sambanis, Anthanassios (Committee Member), Schwartz, Zvi (Committee Member), Wick, Timothy (Committee Member).
Subjects/Keywords: Estrogen; Chondrocyte; Tissue engineering; Sex-specific; Alginate; Electrostatic microencapsulation; Sexual dimorphism (Animals); Articular cartilage; Regeneration (Biology); Osteoarthritis; Estrogen
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
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APA (6th Edition):
Kinney, R. C. (2008). The role of sexual dimorphism in cartilage tissue regeneration. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/28225
Chicago Manual of Style (16th Edition):
Kinney, Ramsey Christian. “The role of sexual dimorphism in cartilage tissue regeneration.” 2008. Doctoral Dissertation, Georgia Tech. Accessed April 13, 2021.
http://hdl.handle.net/1853/28225.
MLA Handbook (7th Edition):
Kinney, Ramsey Christian. “The role of sexual dimorphism in cartilage tissue regeneration.” 2008. Web. 13 Apr 2021.
Vancouver:
Kinney RC. The role of sexual dimorphism in cartilage tissue regeneration. [Internet] [Doctoral dissertation]. Georgia Tech; 2008. [cited 2021 Apr 13].
Available from: http://hdl.handle.net/1853/28225.
Council of Science Editors:
Kinney RC. The role of sexual dimorphism in cartilage tissue regeneration. [Doctoral Dissertation]. Georgia Tech; 2008. Available from: http://hdl.handle.net/1853/28225

Georgia Tech
5.
Rangamani, Padmini.
Bioprocessing Conditions for Improving the Material Properties of Tissue Engineered Cartilage.
Degree: MS, Chemical Engineering, 2005, Georgia Tech
URL: http://hdl.handle.net/1853/7140
► Cartilage tissue engineering is an emerging treatment option for osteoarthritis and trauma related joint injuries. A continuing challenge for cartilage tissue engineering is increasing construct…
(more)
▼ Cartilage tissue engineering is an emerging treatment option for osteoarthritis and trauma related joint injuries. A continuing challenge for cartilage tissue engineering is increasing construct extracellular matrix production and material properties. Shear stress and oxygen tension play an important role in tissue engineering of cartilage. In this select stimulatory conditions using combinations of shear stress and oxygen tension have been used to enhance the construct extracellular matrix deposition and material properties. Additionally, a perfusion concentric cylinder bioreactor has been developed to incorporate multiple fluid flow regimes through the construct.
This thesis attempts to elucidate the effect of shear stress and biochemical conditions on cartilage development in vitro to provide functional tissue engineered constructs.
Advisors/Committee Members: Wick, Timothy (Committee Chair), Boyan, Barbara (Committee Member), Guldberg, Robert (Committee Member), Koros, William (Committee Member), Rousseau, Ronald (Committee Member).
Subjects/Keywords: Bioprocessing; Cartilage; Tissue engineering; Shear flow; Tissue engineering; Biochemical engineering; Bioreactors; Cartilage
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
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APA (6th Edition):
Rangamani, P. (2005). Bioprocessing Conditions for Improving the Material Properties of Tissue Engineered Cartilage. (Masters Thesis). Georgia Tech. Retrieved from http://hdl.handle.net/1853/7140
Chicago Manual of Style (16th Edition):
Rangamani, Padmini. “Bioprocessing Conditions for Improving the Material Properties of Tissue Engineered Cartilage.” 2005. Masters Thesis, Georgia Tech. Accessed April 13, 2021.
http://hdl.handle.net/1853/7140.
MLA Handbook (7th Edition):
Rangamani, Padmini. “Bioprocessing Conditions for Improving the Material Properties of Tissue Engineered Cartilage.” 2005. Web. 13 Apr 2021.
Vancouver:
Rangamani P. Bioprocessing Conditions for Improving the Material Properties of Tissue Engineered Cartilage. [Internet] [Masters thesis]. Georgia Tech; 2005. [cited 2021 Apr 13].
Available from: http://hdl.handle.net/1853/7140.
Council of Science Editors:
Rangamani P. Bioprocessing Conditions for Improving the Material Properties of Tissue Engineered Cartilage. [Masters Thesis]. Georgia Tech; 2005. Available from: http://hdl.handle.net/1853/7140

Georgia Tech
6.
Cheng, Shing-Yi.
Development of a Tissue Engineered Pancreatic Substitute Based on Genetically Engineered Cells.
Degree: PhD, Chemical Engineering, 2005, Georgia Tech
URL: http://hdl.handle.net/1853/7160
► Genetically engineered cells have the potential to solve the cell availability problem in developing a pancreatic tissue substitute for the treatment of insulin-dependent diabetes (IDD).…
(more)
▼ Genetically engineered cells have the potential to solve the cell availability problem in developing a pancreatic tissue substitute for the treatment of insulin-dependent diabetes (IDD). These cells can be beta-cells genetically engineered so that they can be grown in culture, such as the betaTC3 and betaTC tet mouse insulinomas developed by Efrat et al; or, they can be non-beta cells genetically engineered to secrete insulin constitutively or under transcriptional regulation. The aim of this work was to thoroughly characterize and improve the secretion dynamics of pancreatic substitutes based on genetically engineered cells.
One issue involved with the continuous beta-cell lines is the remodeling of the cells inside an encapsulated cell system, which may affect the insulin secretion dynamics exhibited by the construct. To evaluate the effect of remodeling on the secretion properties of the construct, we used a single-pass perfusion system to characterize the insulin secretion dynamics of different alginate beads in response to step-ups and downs in glucose concentration. Results indicated that the secretion dynamics of beads indeed changed after long-term culture. On the other hand, data with a growth-regulated cell line, betaTC tet cells, showed that the secretion profile of beads can be retained if the cell growth is suppressed.
A major concern associated with genetically engineered cells of non-beta origin is that they generally exhibit sub-optimal insulin secretion characteristics relative to normal pancreatic islets. Instead of relying on molecular tools such as manipulating gene elements, our approach was to introduce a glucose-responsive material acting as a control barrier for insulin release from a device containing constitutively secreting cells. Proof-of-concept experiments were performed with a disk-shaped prototype based on recombinant HepG2 hepatomas or C2C12 myoblasts, which constitutively secreted insulin, and concanavalin A (con A)-based glucose-responsive material as the control barrier. Results demonstrated that the a hybrid pancreatic substitute consisting of constitutively secreting cells and glucose-responsive material has the potential to provide a more physiologic regulation of insulin release than the cells by themselves or in an inert material.
Advisors/Committee Members: Sambanis, Athanassios (Committee Chair), Chaikof, Elliot (Committee Member), Lyon, L. Andrew (Committee Member), Thule, Peter (Committee Member), Wick, Timothy (Committee Member).
Subjects/Keywords: Pancreatic substitute; Insulin secretion dynamics; Glucose-responsive; Genetically engineered cells
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
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APA (6th Edition):
Cheng, S. (2005). Development of a Tissue Engineered Pancreatic Substitute Based on Genetically Engineered Cells. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/7160
Chicago Manual of Style (16th Edition):
Cheng, Shing-Yi. “Development of a Tissue Engineered Pancreatic Substitute Based on Genetically Engineered Cells.” 2005. Doctoral Dissertation, Georgia Tech. Accessed April 13, 2021.
http://hdl.handle.net/1853/7160.
MLA Handbook (7th Edition):
Cheng, Shing-Yi. “Development of a Tissue Engineered Pancreatic Substitute Based on Genetically Engineered Cells.” 2005. Web. 13 Apr 2021.
Vancouver:
Cheng S. Development of a Tissue Engineered Pancreatic Substitute Based on Genetically Engineered Cells. [Internet] [Doctoral dissertation]. Georgia Tech; 2005. [cited 2021 Apr 13].
Available from: http://hdl.handle.net/1853/7160.
Council of Science Editors:
Cheng S. Development of a Tissue Engineered Pancreatic Substitute Based on Genetically Engineered Cells. [Doctoral Dissertation]. Georgia Tech; 2005. Available from: http://hdl.handle.net/1853/7160

Georgia Tech
7.
Carnevale, Kevin A.
Finite-Difference Model of Cell Dehydration During Cryopreservation.
Degree: MS, Mechanical Engineering, 2004, Georgia Tech
URL: http://hdl.handle.net/1853/7258
► A numerical model for describing the kinetics of intracellular water transport during cryopreservation was developed. As ice is formed outside the cell, depleting the extracellular…
(more)
▼ A numerical model for describing the kinetics of intracellular water transport during cryopreservation was developed. As ice is formed outside the cell, depleting the extracellular liquid of water, the cell will experience an osmotic pressure difference across its membrane, which causes cell dehydration and concomitant shrinkage. Although Mazur (1963) has previously modeled this phenomenon as a two-compartment system with membrane limited transport, the assumption of well-mixed compartments breaks down at large Biot numbers. Therefore, we have developed a numerical solution to this moving-boundary problem, including diffusive transport in the intracellular liquid, in addition to the osmotically driven membrane flux. Our model uses a modified Crank-Nicolson scheme with a non-uniform Eulerian-Lagrangian grid, and is able to reproduce predictions from Mazurs model at low Biot numbers, while generating novel predictions at high Biot numbers. Given that cell damage may result from excessive water loss, our model can be used to predict freezing methods that minimize the probability of cell injury during the cryopreservation process.
Advisors/Committee Members: Karlsson, Jens (Committee Chair), Udaykumar, H.S. (Committee Member), Wick, Timothy (Committee Member).
Subjects/Keywords: Cryobiology; Cryopreservation; Membrane permeability; Vitrification; Membrane-limited water transport; Diffusion-limited water transport; Crank-Nicolson; Biot number; Peclet number; Dimensional analysis; Cell dehydration; Mathematical models; Finite differences
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Carnevale, K. A. (2004). Finite-Difference Model of Cell Dehydration During Cryopreservation. (Masters Thesis). Georgia Tech. Retrieved from http://hdl.handle.net/1853/7258
Chicago Manual of Style (16th Edition):
Carnevale, Kevin A. “Finite-Difference Model of Cell Dehydration During Cryopreservation.” 2004. Masters Thesis, Georgia Tech. Accessed April 13, 2021.
http://hdl.handle.net/1853/7258.
MLA Handbook (7th Edition):
Carnevale, Kevin A. “Finite-Difference Model of Cell Dehydration During Cryopreservation.” 2004. Web. 13 Apr 2021.
Vancouver:
Carnevale KA. Finite-Difference Model of Cell Dehydration During Cryopreservation. [Internet] [Masters thesis]. Georgia Tech; 2004. [cited 2021 Apr 13].
Available from: http://hdl.handle.net/1853/7258.
Council of Science Editors:
Carnevale KA. Finite-Difference Model of Cell Dehydration During Cryopreservation. [Masters Thesis]. Georgia Tech; 2004. Available from: http://hdl.handle.net/1853/7258

Georgia Tech
8.
Farooque, Tanya Mahbuba.
Biochemical and mechanical stimuli for improved material properties and preservation of tissue-engineered cartilage.
Degree: PhD, Chemical Engineering, 2008, Georgia Tech
URL: http://hdl.handle.net/1853/26710
► Articular cartilage on weight-bearing joints experiences three main forces: fluid-induced shear across the surface, perfusion through the cartilage from the surrounding fluid, and compression during…
(more)
▼ Articular cartilage on weight-bearing joints experiences three main forces: fluid-induced shear across the surface, perfusion through the cartilage from the surrounding fluid, and compression during motion of the joint. A new bioreactor that employs two of these forces was developed in this lab to study their effect on tissue-engineered cartilage development. The focus of this research and overall hypothesis is that bioreactors that employ both perfusion and shear will improve chondrogenesis and preservation to produce functionally relevant cartilage by modulating shear stress and introducing exogenous preservation factors. Applying both a low shear stress across the surface of cell-seeded scaffolds and perfusion through them in a perfusion concentric cylinder (PCC) bioreactor may stimulate chondrocytes to undergo chondrogenesis. Experimental data showed that the PCC bioreactor stimulated cartilage growth over the course of four weeks, supported by the appearance of glycosaminoglycan (GAG) and collagen type II, which are markers for articular cartilage. Computational fluid dynamics modeling showed that shear stress across the face of the construct was heterogeneous, and that only the center experienced a relatively uniform shear stress of 0.4 dynes/cm
2 when the outer cup of the bioreactor rotated at 38 rpm. When compared to a concentric cylinder (CC) bioreactor that employed only shear stress, the PCC bioreactor caused a significant increase in cellular proliferation, which resulted in a 12-fold increase in cell number per construct compared to 7-fold increase within the CC bioreactor. However, the PCC bioreactor had a less pronounced effect on glycosaminoglycan and collagen content with 1.3 mg of GAG and 1.8 mg of collagen per construct within the CC bioreactor and 0.7 mg of GAG and 0.8 mg of collagen per construct within the PCC bioreactor after 28 days in culture (p < 0.05). Our results led to an important observation that the PCC bioreactor affected cellular proliferation significantly but not extracellular matrix synthesis.
The next objective of this study focused on the PCC bioreactor to evaluate the direct role of perfusion and shear on chondrogenesis in vitro and in vivo.
Advisors/Committee Members: Boyan, Barbara (Committee Chair), Wick, Timothy (Committee Chair), Brockbank, Kelvin (Committee Member), Nenes, Athanasios (Committee Member), Sambanis, Athanassios (Committee Member).
Subjects/Keywords: Cryopreservation; Shear stress; Perfusion; Bioreactors; Cartilage; Tissue engineering; Tissue engineering; Articular cartilage; Bioreactors Fluid dynamics; Computational fluid dynamics
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Farooque, T. M. (2008). Biochemical and mechanical stimuli for improved material properties and preservation of tissue-engineered cartilage. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/26710
Chicago Manual of Style (16th Edition):
Farooque, Tanya Mahbuba. “Biochemical and mechanical stimuli for improved material properties and preservation of tissue-engineered cartilage.” 2008. Doctoral Dissertation, Georgia Tech. Accessed April 13, 2021.
http://hdl.handle.net/1853/26710.
MLA Handbook (7th Edition):
Farooque, Tanya Mahbuba. “Biochemical and mechanical stimuli for improved material properties and preservation of tissue-engineered cartilage.” 2008. Web. 13 Apr 2021.
Vancouver:
Farooque TM. Biochemical and mechanical stimuli for improved material properties and preservation of tissue-engineered cartilage. [Internet] [Doctoral dissertation]. Georgia Tech; 2008. [cited 2021 Apr 13].
Available from: http://hdl.handle.net/1853/26710.
Council of Science Editors:
Farooque TM. Biochemical and mechanical stimuli for improved material properties and preservation of tissue-engineered cartilage. [Doctoral Dissertation]. Georgia Tech; 2008. Available from: http://hdl.handle.net/1853/26710
.