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Molecular, Cellular, and Tissue Engineering

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Articles 151 - 178 of 178

Full-Text Articles in Biomedical Engineering and Bioengineering

Impaired Resistance Artery Reactivity Following Arteriogenesis, Michael (Mike) Machado Sep 2011

Impaired Resistance Artery Reactivity Following Arteriogenesis, Michael (Mike) Machado

Biomedical Engineering

No abstract provided.


Protective Effects Of Milk Phospholipids Against Uv Photodamage In Human Skin Equivalents, Zyra Achay Sep 2011

Protective Effects Of Milk Phospholipids Against Uv Photodamage In Human Skin Equivalents, Zyra Achay

Master's Theses and Project Reports

The ultraviolet (UV) spectrum has been known to cause damage to skin in varying degrees. UVB radiation (290-320 nm) in particular, has been proven to be highly mutagenic and carcinogenic in many animal experiments compared to either UVA or UVC. The alarming rate of increase in skin cancer incidence has prompted many investigators to pursue other alternatives to sunscreens including changes in lifestyle habits and dietary consumption in order to boost our efforts in tackling this widespread disease. Previous studies employing confocal reflectance, MTT assay and histology suggest that milk phospholipids may possess protective properties against UVB-mediated damage but the ...


Determining A Method For Rendering Low Cost Cdse(Zns) Core(Shell) Quantum Dots Aqueous Soluble Via Amphiphilic Polymer Wrapping, Patrick Mcbride Jun 2011

Determining A Method For Rendering Low Cost Cdse(Zns) Core(Shell) Quantum Dots Aqueous Soluble Via Amphiphilic Polymer Wrapping, Patrick Mcbride

Materials Engineering

Herein is described the procedure of two amphiphilic polymer wrapping techniques that may be employed for obtaining aqueous soluble quantum dots (QDs) for use in biological fluorescent imaging applications. The advent of QDs has led to new nanoscale fluorescent materials that exhibit unparalleled quantum yields (QYs), high resistance to photobleaching, tunable emissions, and
absorption over a large optical range. However, the QD synthesis employed here at Cal Poly to obtain bright, photostable CdSe(ZnS) core(shell) QDs involves the use of organic solvents and surfactants, leading to hydrophobic QDs. Since all of biology relies on aqueous solubility, this hydrophobicity creates ...


Development Of An In-Vitro Hyperglycemic Tissue Engineered Blood Vessel Mimic, Brian C. Wong Jun 2011

Development Of An In-Vitro Hyperglycemic Tissue Engineered Blood Vessel Mimic, Brian C. Wong

Biomedical Engineering

No abstract provided.


Ischemia Impairs Vasodilation In Skeletal Muscle Resistance Artery, Kyle Remington Struthers Jun 2011

Ischemia Impairs Vasodilation In Skeletal Muscle Resistance Artery, Kyle Remington Struthers

Master's Theses and Project Reports

Functional vasodilation in arterioles is impaired with chronic ischemia. We sought to examine the impact of chronic ischemia and age on skeletal muscle resistance artery function. To examine the impact of chronic ischemia, the femoral artery was resected from young (2-3mo) and adult (6-7mo) mice and the profunda femoris artery diameter was measured at rest and following gracilis muscle contraction 14 days later using intravital microscopy. Functional vasodilation was significantly impaired in ischemic mice (14.4±4.6% vs. 137.8±14.3%, p<0.0001 n=8) and non-ischemic adult mice (103.0±9.4% vs. 137.8±14.3%, p=0.05 n=10). In order to analyze the cellular mechanisms of the impairment, a protocol was developed to apply pharmacological agents to the experimental preparation while maintaining tissue homeostasis. Endothelial and smooth muscle dependent vasodilation were impaired with ischemia, 39.6 ± 13.6% vs. 80.5 ± 11.4% and 43.0 ± 11.7% vs. 85.1 ± 10.5%, respectively. From this data, it can be supported that smooth muscle dysfunction is the reason for the observed impairment in arterial vasodilation.


Implementation And Assessment Of Hyperglycemic Conditions For The Creation Of A Diabetic Blood Vessel Mimic, Vikramaditya Mediratta Jun 2011

Implementation And Assessment Of Hyperglycemic Conditions For The Creation Of A Diabetic Blood Vessel Mimic, Vikramaditya Mediratta

Master's Theses and Project Reports

Introduction: Diabetes Mellitus is a metabolic disorder that affects a person’s ability to either produce insulin (Type I diabetes mellitus) or properly use insulin (Type II diabetes mellitus) in order to maintain adequate blood glucose levels. The most severe diabetic complications arise due to hyperglycemia – a state of extremely high blood glucose levels – such as, coronary artery disease (CAD), in which coronary stent therapy is a popular method of treatment. However, research has shown a high rate of in-stent restenosis in diabetic patients with CAD, most likely due to activation of cellular adhesion molecules on endothelial cells exposed to ...


Regulation Of Tgf-Β1-Induced Apoptosis And Epithelial-Mesenchymal Transition By Matrix Rigidity, Jennifer L. Leight May 2011

Regulation Of Tgf-Β1-Induced Apoptosis And Epithelial-Mesenchymal Transition By Matrix Rigidity, Jennifer L. Leight

Publicly Accessible Penn Dissertations

Transforming growth factor-β (TGF-β) plays an important role in several diseases that characteristically involve changes in tissue rigidity, such as cancer and tissue fibrosis. To determine whether matrix rigidity regulates the effects of TGF-β, we examined NMuMG and MDCK epithelial cells cultured on polyacrylamide gels with varying rigidity and treated with TGF-β1. Decreasing matrix rigidity reduced cell spreading and increased TGF-β1-induced apoptosis, while increasing matrix rigidity resulted in epithelial-mesenchymal transition (EMT). To more carefully control cell spreading, microcontact printing was used to restrict ECM area and revealed that reducing cell spreading also increased apoptosis. Apoptosis on compliant substrates was associated ...


Improvement Of The Immunoisolation Capacity Of Peg Hydrogels Through Bioactive Modifications, Patrick Scott Hume Jan 2011

Improvement Of The Immunoisolation Capacity Of Peg Hydrogels Through Bioactive Modifications, Patrick Scott Hume

Chemical & Biological Engineering Graduate Theses & Dissertations

Cell-based therapies are a promising approach for the treatment of diseases such as Type I diabetes mellitus (TIDM), where endogenous insulin production is restored via delivery of insulin-producing beta-cells or islet of Langerhans clusters. Tissue rejection by the host's immune system, however, is a major hurdle limiting the broad use of transplanted tissues, so beta-cell-based therapies require systemic immunosuppression. To reduce this requirement, tissues have been encapsulated within natural and synthetic barrier materials in a process known as immunoisolation. Immunoisolation materials, including poly (ethylene glycol) (PEG) hydrogels, create physical barriers between host immune cells and donor tissue while enabling ...


Characterization Of Bioreactor System For Tissue Engineered Blood Vessels, Kasim Shah Jan 2011

Characterization Of Bioreactor System For Tissue Engineered Blood Vessels, Kasim Shah

Biomedical Engineering

No abstract provided.


Dendritic Cell Migration And Traction Force Generation In Engineered Microenvironments, Brendon Guenther Ricart Dec 2010

Dendritic Cell Migration And Traction Force Generation In Engineered Microenvironments, Brendon Guenther Ricart

Publicly Accessible Penn Dissertations

Dendritic cells (DCs) are potent initiators of the adaptive immune response. Their trafficking from sites of inflammation to lymphoid tissue is essential to their function. Exactly how dendritic cells integrate multiple chemotactic cues to organize an accurate migratory path is not fully understood. We first characterize DC random motility (chemokinesis) on extracellular matrix proteins in the presence of chemokines. Then, using a microfluidic device, we present both single and competing chemokine gradients to murine bone-marrow derived DCs in a controlled, time-invariant microenvironment. We show that in counter gradients, CCL19 is 10 to 100 fold more potent than other chemokines CCL21 ...


Characterization And Analysis Techniques Of A Dynamic In Vitro Blood-Brain Barrier Model, Ryan Everett Woodhouse Dec 2010

Characterization And Analysis Techniques Of A Dynamic In Vitro Blood-Brain Barrier Model, Ryan Everett Woodhouse

Biomedical Engineering

The blood-brain barrier (BBB) is responsible for maintaining the sensitive environment required by the brain. Although the BBB is necessary for proper functioning of the brain, it acts as an obstacle for doctors attempting to treat neurological disease. For a drug to act upon the brain, it must first pass through the discriminating BBB. For this reason, much research has been performed in recent years in order to create an in vitro model of the BBB on which drugs targeted for the central nervous system may be tested. The main goal of this project is to create an in vitro ...


Meniscus Tissue Engineering With Nanofibrous Scaffolds, Brendon M. Baker Aug 2010

Meniscus Tissue Engineering With Nanofibrous Scaffolds, Brendon M. Baker

Publicly Accessible Penn Dissertations

The fibrocartilaginous menisci dwell between the articular surfaces of the knee and play a central role in joint function. Damage through trauma or degenerative changes is a common orthopaedic injury, disrupts the meniscus mechanical function, and leads to the precocious development of osteoarthritis. The current standard of treatment is removal of the damaged tissue, a procedure that does not re-establish normal knee mechanics. Given the frequency of meniscal injury, a restorative repair strategy remains a major unmet need in orthopaedic medicine. With the goal of replacing damaged meniscus with engineered biologic tissue that can restore meniscal function, this work focuses ...


Combinatorial Polymer Synthesis And High-Throughput Screening Technology To Identify Optimal Approaches For Mineralized Tissue Engineering, Darren M. Brey Aug 2010

Combinatorial Polymer Synthesis And High-Throughput Screening Technology To Identify Optimal Approaches For Mineralized Tissue Engineering, Darren M. Brey

Publicly Accessible Penn Dissertations

The general tissue engineering approach is to combine cells, scaffolding, and signaling molecules in a manner that treats damaged or diseased tissues. Progress in the field has been made incrementally since changes to these inputs require meticulous iterative steps. However, recent advances in combinatorial chemistry and high through-put screening (HTS) technology have made available a wider range of potential scaffold materials with diverse properties, as well as new methods to accelerate the process of testing soluble factors or combinations of factors.

To this end, a library of poly(β-amino ester)s has been developed as the first combinatorial library of ...


Enhancing Mesenchymal Stem Cell Chondrogenesis For Cartilage Tissue Engineering, Alice H. Huang Aug 2010

Enhancing Mesenchymal Stem Cell Chondrogenesis For Cartilage Tissue Engineering, Alice H. Huang

Publicly Accessible Penn Dissertations

Articular cartilage provides a bearing surface for transmitting forces across joints. The poor ability of cartilage to self-repair has motivated efforts to engineer replacement tissues, and mesenchymal stem cells (MSCs), which can undergo chondrogenesis, have emerged as a promising cell source. To date however, the functional properties of MSC-based constructs remain lower than those of the native tissue and of chondrocyte-based constructs cultured identically. Therefore, the overall objective of this thesis is to better understand the transcriptional and functional limitations underlying chondrogenic differentiation and enhance MSC chondrogenesis.

Toward this end, established tissue engineering strategies from the chondrocyte literature were applied ...


Regulation Of Angiogenesis By Adhesive And Mechanical Cues From The Extracellular Matrix, Colette Shen May 2010

Regulation Of Angiogenesis By Adhesive And Mechanical Cues From The Extracellular Matrix, Colette Shen

Publicly Accessible Penn Dissertations

Angiogenesis, the sprouting of new capillaries from existing blood vessels, is essential for the survival of tissues and normally occurs during development and wound healing. Successful vascularization of engineered tissues is currently a major challenge, as it is critical for the survival and incorporation of implanted tissue replacements. While the role of soluble factors in regulating angiogenesis is well established, there is significant interest in uncovering the contributions of cellular interactions with the extracellular matrix (ECM). We chose to study the role of cell-ECM adhesion in regulating angiogenesis, with the hypothesis that quantitative changes in the degree of cell-ECM adhesion ...


Biochemical And Biomechanical Modulation Of Nucleus Pulposus Cells Encapsulated In Novel Cellulose-Based Hydrogels, Anna T. Reza Dec 2009

Biochemical And Biomechanical Modulation Of Nucleus Pulposus Cells Encapsulated In Novel Cellulose-Based Hydrogels, Anna T. Reza

Publicly Accessible Penn Dissertations

Low back pain may be caused by a direct, acute injury or degeneration of the intervertebral disc (IVD). Intradiscal replacement of the nucleus pulposus (NP) with a tissue engineered hydrogel scaffold may provide a biologic therapy capable of restoring the structure and mechanical function of the IVD. Therefore, the global objective of this dissertation was to develop and optimize a novel, cell-laden, covlently crosslinkable carboxymethylcellulose (CMC) hydrogel construct as a functional tissue engineered NP replacement. The versatility of the photocrosslinkable CMC system was explored by examining the resultant differences in material and mechanical properties due to varying the macromer concentration ...


Differential Cellular Response To Linear And Strain Stiffening Hydrogel Substrates, Jessamine P. Winer Dec 2009

Differential Cellular Response To Linear And Strain Stiffening Hydrogel Substrates, Jessamine P. Winer

Publicly Accessible Penn Dissertations

The mechanical properties of the substrate upon which cells are cultured have been shown to influence a variety of cell properties including cell adhesion, spreading, protein expression and differentiation. The work presented here examines how the nonlinear mechanical properties of biopolymer gels affect the cellular responses to substrate stiffness. Cell spread area decreases with decreasing substrate stiffness when cells are cultured on linearly elastic polyacrylamide gels but display no spread area sensitivity when cultured on fibrin gels of various moduli. Fibrin gels, and other semiflexible biopolymer networks, exhibit strain stiffening, whereby the elastic modulus of the gel increases with increasing ...


The Electrical Properties Of Human Tissue For The Diagnosis And Treatment Of Melanoma Skin Cancer, Glenn Cameron Stante Dec 2009

The Electrical Properties Of Human Tissue For The Diagnosis And Treatment Of Melanoma Skin Cancer, Glenn Cameron Stante

Master's Theses and Project Reports

This thesis discusses the research, experimental methods, and data gathered for the investigation of a novel method for the diagnosis of melanoma skin cancer. First, a background about human skin tissue is presented. Then, a detailed description of melanoma along with current diagnosis techniques and treatment options are presented. In the experimental methods, the electrical properties of several types of tissue were analyzed, the purpose of which was to discover if a tissue type can be distinguished by its electrical properties alone. This would allow for the diagnosis of melanoma to be done by examining the electrical properties of the ...


Regression Analysis Of Fracture Toughness For Secondary Osteons Located In Human Cortical Bone, Chase A. Fetzer Oct 2009

Regression Analysis Of Fracture Toughness For Secondary Osteons Located In Human Cortical Bone, Chase A. Fetzer

Master's Theses and Project Reports

An experiment was carried out in order to locate and quantify osteon types within a sample of cortical bone taken from a human tibia. This was done using a microscope-camera assembly and the BioQuant computer software. The results of this were correlated with a previous experiment’s results on fracture toughness so that an analysis could be run on the data in order to determine the factors that most affect the value of fracture toughness of this cortical bone. Results were examined closely and the analysis repeated until the author was satisfied that the best possible model for fracture toughness ...


Assessment Of Electrospinning As An In-House Fabrication Technique For Blood Vessel Mimic Cellular Scaffolding, Colby M. James Sep 2009

Assessment Of Electrospinning As An In-House Fabrication Technique For Blood Vessel Mimic Cellular Scaffolding, Colby M. James

Master's Theses and Project Reports

Intravascular devices, such as stents, must be rigorously tested before they can be approved by the FDA. This includes bench top in vitro testing to determine biocompatibility, and animal model testing to ensure safety and efficacy. As an intermediate step, a blood vessel mimic (BVM) testing method has been developed that mimics the three dimensional structure of blood vessels using a perfusion bioreactor system, human derived endothelial cells, and a biocompatible polymer scaffold used to support growth of the blood vessel cells. The focus of this thesis was to find an in-house fabrication method capable of making cellular scaffolding for ...


Mechanical And Chemical Effects In Adhesion Of Thin Shell Structures With Applications In Wafer Bonding And Adhesion Of Living Cells, Richard M. Springman Aug 2009

Mechanical And Chemical Effects In Adhesion Of Thin Shell Structures With Applications In Wafer Bonding And Adhesion Of Living Cells, Richard M. Springman

Publicly Accessible Penn Dissertations

A theoretical model is analyzed to investigate the adhesion of thin shell structures to both rigid and deformable substrates under a variety of surface conditions. The thermodynamic forces driving the adhesive process are determined from an interfacial free energy, which is described within a classical thermodynamics framework. Deformations of the thin, elastic shells are studied using a geometrically nonlinear shell theory. Finite-range adhesive tractions, chemical segregation, substrate compliance, and substrate topography all are considered over a wide range of geometric and material parameters. Equilibrium adhesion states are characterized by a shell flatness parameter, the contact radius, and the adhesive and ...


Preparation And Characterization Of Electrospun Poly(D,L-Lactide-Co-Glycolide) Scaffolds For Vascular Tissue Engineering And The Advancement Of An In Vitro Blood Vessel Mimic, Tiffany Richelle Pena Jun 2009

Preparation And Characterization Of Electrospun Poly(D,L-Lactide-Co-Glycolide) Scaffolds For Vascular Tissue Engineering And The Advancement Of An In Vitro Blood Vessel Mimic, Tiffany Richelle Pena

Master's Theses and Project Reports

PREPARATION AND CHARACTERIZATION OF ELECTROSPUN POLY(D,L-LACTIDE-CO-GLYCOLIDE) SCAFFFOLDS FOR VASCULAR TISSUE ENGINEERING AND THE ADVANCEMENT OF AN IN VITRO BLOOD VESSEL MIMIC

Tiffany Richelle Peña

Currently, an estimated 1 in every 3 adult Americans are affected by one or more cardiovascular complications. The most common complication is coronary artery disease, specifically atherosclerosis. Outcomes of balloon angioplasty treatments have been significantly improved with the addition of drug eluting stents to the process. Although both bare metal and drug eluting stents have greatly increased the effectiveness of angioplasty and decreased the occurrence of restenosis, several complications still exist. For this reason ...


Development Of An In-Vitro Tissue Engineered Blood Vessel Mimic Using Human Large Vessel Cell Sources, Dimitri E. Delagrammaticas May 2009

Development Of An In-Vitro Tissue Engineered Blood Vessel Mimic Using Human Large Vessel Cell Sources, Dimitri E. Delagrammaticas

Master's Theses and Project Reports

Tissue engineering is an emerging field that offers novel and unmatched potential medical therapies and treatments. While the vast aim of tissue engineering endeavors is to provide clinically implantable constructs, secondary applications have been developed to utilize tissue-engineered constructs for in-vitro evaluation of devices and therapies. Specifically, in-vitro blood vessel mimics (BVM) have been developed to create a bench-top blood vessel model using human cells that can be used to test and evaluate vascular disease treatments and intravascular devices. Previous BVM work has used fat derived human microvascular endothelial cells (EC) sodded on an ePTFE scaffold. To create a more ...


Nano-Mechanics Of Cartilage Glycosaminoglycans Using Molecular Dynamics Methods, Kevin Neil Hendrickson Jan 2009

Nano-Mechanics Of Cartilage Glycosaminoglycans Using Molecular Dynamics Methods, Kevin Neil Hendrickson

Master's Theses and Project Reports

Articular Cartilage (AC) is the main load carrying material in synovial joints {Hamerman, 1962} and degeneration of AC can cause pain in the form of arthritis. Current work is centered on the method of replacing damaged cartilage inside the body (in vivo) with tissue engineered outside the body (ex vivo) {Temenoff, 2000}. In order to engineer tissue ex vivo similar to the native tissue in structure and function there must be a comprehensive understanding of the mechanical properties of AC. This work focuses on the study of glycosaminoglycans (GAGs), a molecule known to be primarily responsible for the compressive stiffness ...


Development Of A Cell Depositing System Using Inkjet Technology, Jason Robert Ozaeta Jun 2008

Development Of A Cell Depositing System Using Inkjet Technology, Jason Robert Ozaeta

Master's Theses and Project Reports

In the past decade, advances in tissue engineering have allowed researchers to fabricate simple tissues. However, the process of creating these native tissues is a time consuming and inefficient process. A scaffold must first be fabricated then exposed to a sea of cells in the hopes of seeding. Furthermore, even though cells may have attached, more time must be spent in order to allow the cells to migrate to their ideal locations. To deal with this problem, researchers have investigated whether rapid prototyping principals could be adapted to facilitate the cell seeding process by placing cells in their respective locations ...


Generation Of Recombinant Mouse Embryonic Stem Cell Lines And Theirapplication For In Vivo Bioluminiscence Imaging In The Heart, Ramana Kammili Jan 2008

Generation Of Recombinant Mouse Embryonic Stem Cell Lines And Theirapplication For In Vivo Bioluminiscence Imaging In The Heart, Ramana Kammili

Electronic Theses and Dissertations

Cardiovascular disease is the major cause of death in the United States, with 80 million people suffering from some form of heart disease each year. One major limitation is the inability of the heart to repair the damaged tissue. Stem cell therapy holds enormous promise to repair and regenerate the damaged myocardium, but there are many technical difficulties that must first be overcome. One such difficulty is the present lack of ability to track and assess transplanted stem cells over time in vivo. The central hypothesis of this thesis is that in vivo bioluminescence imaging is a safe and useful ...


The Competitive Effects Of Medroxyprogesterone Acetate (Mpa) In Vitro And In Vivo On Hypothalmic Androgen Binding In Cf-L Male Mice, Michael Patrick Perry Jan 1989

The Competitive Effects Of Medroxyprogesterone Acetate (Mpa) In Vitro And In Vivo On Hypothalmic Androgen Binding In Cf-L Male Mice, Michael Patrick Perry

Theses and Dissertations

No abstract provided.


A Quantitative Analysis By Emission Spectroscopy Of The Metallic Constituents Of Biological Samples After Treatment By A Carcinogenic Agent, Charles R. Frydrych Dec 1972

A Quantitative Analysis By Emission Spectroscopy Of The Metallic Constituents Of Biological Samples After Treatment By A Carcinogenic Agent, Charles R. Frydrych

Master's Theses

No abstract provided.