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Theses/Dissertations

Chemical & Biological Engineering Graduate Theses & Dissertations

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Diagnostics And Selective Nano-Therapeutics To Combat Multidrug-Resistant Bacteria, Partha Pratim Chowdhury Jan 2019

Diagnostics And Selective Nano-Therapeutics To Combat Multidrug-Resistant Bacteria, Partha Pratim Chowdhury

Chemical & Biological Engineering Graduate Theses & Dissertations

Due to extensive use of antibiotics various strains multidrug resistant bacteria are emerging rapidly. In USA alone according to CDC report 2013 more than 2 million is affected by these strains of multidrug resistant bacteria causing several deaths. Hence an effective way of diagnostics and therapeutics need to be designed which can successfully combat the menace of

multidrug drug resistant bacteria.

In the present thesis, we discuss about novel strategies for both diagnostics and therapeutics for multidrug resistant bacteria. In the 1st chapter we discuss a novel DNA sequencing technique utilizing purely optical spectroscopy techniques like surface enhanced Raman and ...


Computational Protein Design For Peptide-Directed Bioconjugation, Joseph Gabriel Plaks Jan 2019

Computational Protein Design For Peptide-Directed Bioconjugation, Joseph Gabriel Plaks

Chemical & Biological Engineering Graduate Theses & Dissertations

Proteins enable living organisms to perform many of their critical functions, having been applied over evolutionary time to solve problems of overwhelming diversity and complexity. Protein engineering seeks to deploy these versatile molecules in addressing problems of human concern and would benefit from innovations that improve protein utilization in unnatural environments as well as from increased predictive capability in protein design.

Bioconjugation facilitates the use of proteins in unnatural environments by permitting the attachment of molecules, such as polymers, that can modulate protein stability, solubility, and activity and by mediating protein immobilization. We initially explored this propensity of bioconjugation by ...


Engineering Bacterial Gene Expression: Applications Towards Biofuels And Antibiotic Resistance, Peter Britton Otoupal Jan 2018

Engineering Bacterial Gene Expression: Applications Towards Biofuels And Antibiotic Resistance, Peter Britton Otoupal

Chemical & Biological Engineering Graduate Theses & Dissertations

Nature is rarely static. Organisms live in diverse and stressful environments that necessitate rapid response strategies for survival. Microorganisms have responded to this by evolving bet-hedging, wherein they exhibit constitutively heterogeneous gene expression to maximize fitness across numerous background. The goal of this thesis is to “hijack” this phenomenon using novel gene expression engineering techniques to alter how bacteria respond to their environments, in order to address pressing societal concerns.

This begins with a systematic exploration of how bacterial gene expression naturally responds to antibiotics and biofuels. This reveals promising gene candidates for targeted manipulation, for which a library of ...


The Role Of Protein-Protein Interactions In Inducing Interfacial Aggregation, Lea Line Gisele Sorret Jan 2018

The Role Of Protein-Protein Interactions In Inducing Interfacial Aggregation, Lea Line Gisele Sorret

Chemical & Biological Engineering Graduate Theses & Dissertations

The synergic exposure to silicone oil-water interfaces and to agitation has been shown to promote the aggregation of therapeutic proteins. Silicone oil is typically used as a lubricant for manufacturing surfaces and pharmaceutical containers such as glass prefilled syringes. This is a problem as protein aggregates formed at the silicone oil-water interface may shed into bulk solutions, leading to product recalls or adverse immunogenicity upon injections into patients.

Protein aggregation in solution occurs as a result of attractive protein-protein interactions (PPI). PPI can be characterized using techniques such as dynamic light scattering which measures the dependence of molecular diffusivity on ...


In Situ Designer Lipid Production: Integration Of Novel Characteristics And Behaviors Into Synthetic Cell Membranes, Danielle S. Konetski Jan 2018

In Situ Designer Lipid Production: Integration Of Novel Characteristics And Behaviors Into Synthetic Cell Membranes, Danielle S. Konetski

Chemical & Biological Engineering Graduate Theses & Dissertations

This thesis investigated the coupling of lysolipids and functionalized tails for in situ formation of synthetic liposomes designed to enable specific characteristics or behaviors in applications ranging from drug delivery to the advancement of artificial cell development. Copper-catalyzed Azide-Alkyne Cycloaddition (CuAAC) mediated lipid coupling was improved via incorporation of a photoinitiation system. Here, photo-CuAAC enabled spatiotemporal control over liposome assembly, an over 400-fold increase in formation density, and control over the maximal cross-sectional area of the liposomes formed.

Thiol-Michael mediated lipid coupling was enabled using thiol-functionalized lysolipids and acrylate tails where phospholipids were produced over 48 hours with approximate 90 ...


Biomimetic Hydrogels To Support Bone Development For Osteochondral Tissue Engineering Applications, Aaron H. Aziz Jan 2018

Biomimetic Hydrogels To Support Bone Development For Osteochondral Tissue Engineering Applications, Aaron H. Aziz

Chemical & Biological Engineering Graduate Theses & Dissertations

Osteochondral tissue engineering using multilayer hydrogel scaffolds to recapitulate the native layered structure serves as a promising strategy to repair and regenerate osteochondral defects due to joint trauma, injuries, and long-term diseases. The gold standard of clinical therapies relies on replacing the defect with autologous tissue from a non load-bearing site, yet these techniques often fail due to a lack of mechanical anchoring, donor site morbidity and tissue availability. Multilayered photopolymerizable poly(ethylene glycol) (PEG) hydrogels, with a bony layer that facilitates osteoconductivity and osseointegration present an opportunity to overcome these issues. Ensuring multilayer hydrogels supported bone growth within the ...


Modeling And Designing Genetic Devices Using Transcriptional Interference In Escherichia Coli, Antoni Escalas Bordoy Jan 2018

Modeling And Designing Genetic Devices Using Transcriptional Interference In Escherichia Coli, Antoni Escalas Bordoy

Chemical & Biological Engineering Graduate Theses & Dissertations

Microorganisms inhabit every extreme location of our planet. In their journey through the ages, they have been able to incredibly adapt to a myriad of different environmental conditions. A key mechanism for their success has been their ability to respond to environmental and nutritional changes through regulatory programs primarily encoded at the transcriptional level. This adaptability to new environments is what encourages scientists to believe in engineering a biological revolution that will transform our lives due to its potential to result in innovative approaches for bioremediation, sustainable energy production, and biomedical therapies. This thesis explores the potential of the phenomenon ...


Modifying Supported Palladium Catalysts Using Self-Assembled Monolayers For Liquid-Phase Reactions, Pengxiao Hao Jan 2018

Modifying Supported Palladium Catalysts Using Self-Assembled Monolayers For Liquid-Phase Reactions, Pengxiao Hao

Chemical & Biological Engineering Graduate Theses & Dissertations

In this thesis, we investigate the modification of Pd/Al2O3 catalyst using thiolate and phosphonate self-assembled monolayers (SAMs) for two types of reactions in liquid-phase environments: selective oxidation of α, β-unsaturated alcohols and vanillin hydrodeoxygenation. Through the study, we aim to gain a better understanding of the liquid-solid interface that governs the catalytic activity.

The selective oxidation of a linear unsaturated alcohol trans-2-hexen-1-ol (HOL) was studied on Pd/Al2O3 catalysts in heptane. Alkanethiolate self-assembled monolayers (SAMs) were applied to modify Pd/Al2O3 catalysts; the sulfur content on the Pd surface was ...


Connecting Protein Structure And Dynamics On Biomaterials With The Foreign Body Response, David Faulon Marruecos Jan 2018

Connecting Protein Structure And Dynamics On Biomaterials With The Foreign Body Response, David Faulon Marruecos

Chemical & Biological Engineering Graduate Theses & Dissertations

The harsh environment of the foreign body response (FBR) has the potential to negatively impact the implantations of biomaterials in the body. The FBR is initiated by inflammatory cells that recognize the material as foreign through surface-adsorbed proteins. When proteins interact with surfaces, they can unfold and expose epitopes that may be recognized by immune cells and trigger a series of reactions. Importantly, the presentation of unfolded proteins is directly influenced by the highly dynamic and heterogeneous behavior of proteins in near-surface environments, as well as by the physicochemical features of the underlying surface. Such behavior is the result of ...


Multicatalytic, Light-Driven Reactions For Improved Biofuels And Wastewater Remediation, Glenn Richard Hafenstine Jan 2018

Multicatalytic, Light-Driven Reactions For Improved Biofuels And Wastewater Remediation, Glenn Richard Hafenstine

Chemical & Biological Engineering Graduate Theses & Dissertations

Utilizing solar driven photocatalysis to facilitate coupling reaction systems is a promising route for low-energy and selective production of valuable chemicals. My doctoral research has focused on using photocatalytic cadmium sulfide nanorods to run novel reaction systems under mild, ambient conditions with sunlight as the only energy source. In this dissertation, I will first describe a cascade reaction system for catalytic upgrading of the fermentation products butanol and ethanol into an easily separated product in 2-ethylhexenal with a higher energy density. Specifically, I will report the use of the enzyme alcohol dehydrogenase, regeneration of the enzymatic cofactor by the photocatalyst ...


The Role Of Physiochemical Cues On Msc Differentiation And Tissue Regeneration In A Cartilage Biomimetic Hydrogel, Elizabeth Anne Aisenbrey Jan 2017

The Role Of Physiochemical Cues On Msc Differentiation And Tissue Regeneration In A Cartilage Biomimetic Hydrogel, Elizabeth Anne Aisenbrey

Chemical & Biological Engineering Graduate Theses & Dissertations

Cartilage defects, whether caused by injury or disease, often lead to further degeneration and ultimately osteoarthritis. Current treatments such as autologous chondrocyte implantation (ACI) and microfracture have shown limited success at repairing and regenerating cartilage tissue, thus an alternative treatment is necessary. Cartilage tissue engineering using scaffolds as a vehicle to deliver cells, biochemical cues, and soluble factors presents a promising strategy to regenerate cartilage tissue. Photopolymerizable poly(ethylene glycol) (PEG) hydrogels that can be modified with different biochemical moieties, degradable and nondegradable peptides, and therapeutic agents are an attractive platform to design and develop scaffolds that can be tailored ...


Modeling Alveolar Epithelial Cell Behavior In Spatially Designed Hydrogel Microenvironments, Katherine Jean Reeder Lewis Jan 2016

Modeling Alveolar Epithelial Cell Behavior In Spatially Designed Hydrogel Microenvironments, Katherine Jean Reeder Lewis

Chemical & Biological Engineering Graduate Theses & Dissertations

The alveolar epithelium consists of two cell phenotypes, elongated alveolar type I cells (AT1) and rounded alveolar type II cells (ATII), and exists in a complex three-dimensional environment as a polarized cell layer attached to a thin basement membrane and enclosing a roughly spherical lumen. Closely surrounding the alveolar cysts are capillary endothelial cells as well as interstitial pulmonary fibroblasts. Many factors are thought to influence alveolar epithelial cell differentiation during lung development and wound repair, including physical and biochemical signals from the extracellular matrix (ECM), and paracrine signals from the surrounding mesenchyme. In particular, disrupted signaling between the alveolar ...


Use Of Biofunctional Hydrogel Matrices For Chondrocyte Transplantation Applications, Balaji V. Sridhar Jan 2015

Use Of Biofunctional Hydrogel Matrices For Chondrocyte Transplantation Applications, Balaji V. Sridhar

Chemical & Biological Engineering Graduate Theses & Dissertations

Healing joint articular cartilage is a significant clinical challenge because it lacks self-healing properties. Focal defects that do not heal properly tend to progress to debilitating osteoarthritis that affects millions of people worldwide. Tissue engineering strategies that utilize biofunctional scaffolds as chondrocyte carriers present a promising treatment option to regenerate cartilage tissue. Autologous chondrocytes are a good cell source since they regulate cartilage extracellular matrix (ECM) production in the tissue. Cells can be combined with photopolymerizable scaffolds, which permit control over network formation and can be modified to present biological cues. Current treatment options for cartilage regeneration have generally yielded ...


Regulation Of Melanoma Cell Survival And Function By Matricellular Signaling And Microenvironmental Factors, Emi Yuriko Tokuda Jan 2015

Regulation Of Melanoma Cell Survival And Function By Matricellular Signaling And Microenvironmental Factors, Emi Yuriko Tokuda

Chemical & Biological Engineering Graduate Theses & Dissertations

Metastatic melanoma is an aggressive, drug resistant form of skin cancer. Despite the recent development of several new therapeutics, patients typically relapse within 6 months of starting treatment. Consequently, researchers are working to understand the mechanisms of melanoma drug resistance and the key factors that impact its survival. Because cell-ECM (extracellular matrix) interactions alter outside-in signaling and relay information about the surrounding tissue to a cell, the cellular microenvironment can regulate cell function and this, in turn, may influence melanoma responsiveness to pharmacological inhibition. Preclinical studies have shown differential drug efficacy between traditional tissue culture-treated polystyrene (TCPS) and multicellular spheroids ...


Improved Methods For Understanding Sparse, Multi-Dimensional, High Throughput Sequencing Data, Sophie J. Weiss Jan 2015

Improved Methods For Understanding Sparse, Multi-Dimensional, High Throughput Sequencing Data, Sophie J. Weiss

Chemical & Biological Engineering Graduate Theses & Dissertations

Tremendous advances in genetic and sequencing technology are enabling unprecedented insight into human disease, forensics, and cellular mechanisms, to name a few. Conclusions drawn from these studies are strongly influenced by the interpretation of their associated massive data sets. The goal of this thesis is to understand, develop, and apply algorithms to help overcome common ecological and biological sequencing study challenges: contamination, differences in sampling efforts, a very large amount of zeroes, and compositionality.

We use simulations and experimental data to understand how different matrix normalization strategies mitigate the effects of the aforementioned challenges on downstream analyses, particularly principal coordinate ...


The Immunogenicity Of Therapeutic Protein Formulations Containing Silicone Oil Microdroplets, Carly Fleagle Chisholm Jan 2015

The Immunogenicity Of Therapeutic Protein Formulations Containing Silicone Oil Microdroplets, Carly Fleagle Chisholm

Chemical & Biological Engineering Graduate Theses & Dissertations

Subvisible particles in therapeutic protein products may act as adjuvants to provoke unwanted immune responses against administered proteins. Silicone oil is used as a lubricant in prefilled syringes, and microdroplets of silicone oil are frequently detected in protein formulations expelled from prefilled syringes. In this work, we investigated the potential of silicone oil microdroplets to act as an adjuvant to elicit immune responses against formulations containing foreign or self-protein in vivo.

First, we tested the immunogenicity of formulations that contained a foreign protein and silicone oil microdroplets. A foreign model protein, ovalbumin (OVA), was added to emulsions of silicone oil ...


The Role Of Matrix Properties In Directing Valvular Interstitial Cell Phenotype, Kelly Marie Pollock Mabry Jan 2015

The Role Of Matrix Properties In Directing Valvular Interstitial Cell Phenotype, Kelly Marie Pollock Mabry

Chemical & Biological Engineering Graduate Theses & Dissertations

This thesis presents the development of hydrogel platforms to study the fibroblast-to-myofibroblast transition in valvular interstitial cells (VICs). These systems were used to characterize the effects of extracellular matrix cues on VICs, as well as the synergies between mechanical and biochemical signals. First, the impact of culture platform on VIC phenotype was assessed by culturing VICs in peptide-functionalized poly(ethylene glycol) hydrogels (2D and 3D) and comparing them to those cultured on tissue culture polystyrene (TCPS). Expression of the myofibroblast marker α-smooth muscle actin (αSMA), as well as by a global analysis of the transcriptional profiles1 demonstrated that TCPS ...


Bioactive Sutures To Prevent Fibrosis In Injured Skeletal Muscle Tissue, Núria Codina Castillo Jul 2014

Bioactive Sutures To Prevent Fibrosis In Injured Skeletal Muscle Tissue, Núria Codina Castillo

Chemical & Biological Engineering Graduate Theses & Dissertations

Primitive animals and earl mammalian embryos have the capacity to respond to injury by regenerating the affected tissue. Most tissues in the human body, however, follow an inferior method of wound repair that finishes with an accumulation of collagen, also known as scar tissue. Scar tissue blocks progenitor cells from infiltrating the site of injury, resulting in incomplete regeneration. Slowing the fibrotic response would shift the wound repair process towards regeneration and considerably improve human health.

The primary goal of this project is to develop novel bioactive sutures for preventing fibrosis in injured skeletal muscle. This will be achieved by ...


Tuning Hydrogel Degradation For Cartilage Tissue Engineering, Stacey Skaalure Jul 2014

Tuning Hydrogel Degradation For Cartilage Tissue Engineering, Stacey Skaalure

Chemical & Biological Engineering Graduate Theses & Dissertations

Cartilage tissue engineering using biodegradable scaffolds as carriers for cartilage cells (chondrocytes) presents a promising strategy to regenerate cartilage damaged by age, injury, or disease. State-of-the-art clinical therapies implement chondrocytes harvested from the patient, however these treatments suffer from patient-to-patient variability and ineffectiveness due to aging. Photopolymerizable poly(ethylene glycol) (PEG) hydrogel scaffolds that can be modified to permit tunable degradation present an opportunity to tailor scaffolds to the patient's cells. Scaffold degradation is crucial to encourage cartilaginous matrix deposition by entrapped chondrocytes, however the rate of degradation must be matched to matrix deposition, which is a significant design ...


Process Extension From Embryonic Stem Cell-Derived Motor Neurons Through Synthetic Extracellular Matrix Mimics, Daniel Devaud Mckinnon Jan 2014

Process Extension From Embryonic Stem Cell-Derived Motor Neurons Through Synthetic Extracellular Matrix Mimics, Daniel Devaud Mckinnon

Chemical & Biological Engineering Graduate Theses & Dissertations

This thesis focuses on studying the extension of motor axons through synthetic poly(ethylene glycol) PEG hydrogels that have been modified with biochemical functionalities to render them more biologically relevant. Specifically, the research strategy is to encapsulate embryonic stem cell-derived motor neurons (ESMNs) in synthetic PEG hydrogels crosslinked through three different chemistries providing three mechanisms for dynamically tuning material properties. First, a covalently crosslinked, enzymatically degradable hydrogel is developed and exploited to study the biophysical dynamics of axon extension and matrix remodeling. It is demonstrated that dispersed motor neurons require a battery of adhesive peptides and growth factors to maintain ...


Real-Time Single-Molecule Observations Of Proteins At The Solid-Liquid Interface, Blake Brianna Langdon Jan 2014

Real-Time Single-Molecule Observations Of Proteins At The Solid-Liquid Interface, Blake Brianna Langdon

Chemical & Biological Engineering Graduate Theses & Dissertations

Non-specific protein adsorption to solid surfaces is pervasive and observed across a broad spectrum of applications including biomaterials, separations, pharmaceuticals, and biosensing. Despite great interest in and considerable literature dedicated to the phenomena, a mechanistic understanding of this complex phenomena is lacking and remains controversial, partially due to the limits of ensemble-averaging techniques used to study it. Single-molecule tracking (SMT) methods allow us to study distinct protein dynamics (e.g. adsorption, desorption, diffusion, and intermolecular associations) on a molecule-by-molecule basis revealing the protein population and spatial heterogeneity inherent in protein interfacial behavior. By employing single-molecule total internal reflection fluorescence microscopy ...


Controlled Formation Of Beta-Cell Aggregates And Their Characterization, Abigail Banaszek Bernard Jan 2013

Controlled Formation Of Beta-Cell Aggregates And Their Characterization, Abigail Banaszek Bernard

Chemical & Biological Engineering Graduate Theses & Dissertations

Islets of Langerhans are multi-cellular aggregates within the pancreas containing β-cells that sense changes in blood glucose levels and respond by secreting insulin. Transplantation of these functional cell clusters represents a promising avenue for the treatment of severe cases of type 1 diabetes mellitus but much remains unknown about key aspects of cell-cell and cell-matrix communication that influence cell survival post-transplantation. Cell-cell contact between islet cells is crucial for cell survival and maintenance of glucose-dependent insulin release but large islets exhibit necrosis of central cells under transplant conditions. To facilitate cell-cell contact but limit aggregate size, several methods have been ...


Hydrogels For Cartilage Tissue Engineering In Mechanically Relevant Environments, Justine Jenna Roberts Jan 2013

Hydrogels For Cartilage Tissue Engineering In Mechanically Relevant Environments, Justine Jenna Roberts

Chemical & Biological Engineering Graduate Theses & Dissertations

Tissue engineering offers the potential to replace cartilage that is damaged due to age, injury, or disease with a native equivalent produced by a chondrocyte (cartilage cell)-laden scaffold. Although joints are highly dynamic environments, scaffolds designed for articular cartilage tissue engineering are often developed in static environments. This raises questions as to whether they will translate to the highly dynamic mechanical environment found in vivo. In healthy joints, cartilage experiences maximum strains of 30% and frequencies from 0.1-2 Hz. This environment leads to the induction of fluid flow and dynamic cellular deformation, both of which can be sensed ...


Integrin Binding Peptide-Functionalized Poly(Ethylene Glycol) Hydrogels For Understanding The Role Of Matricellular Effects On Vic Phenotype And Tissue Deposition, Sarah Trexler Gould Jan 2013

Integrin Binding Peptide-Functionalized Poly(Ethylene Glycol) Hydrogels For Understanding The Role Of Matricellular Effects On Vic Phenotype And Tissue Deposition, Sarah Trexler Gould

Chemical & Biological Engineering Graduate Theses & Dissertations

Aortic valve stenosis (AS) results in almost 100,000 valve replacement surgeries per year in the United States. These replacements are generally made of synthetic materials that require anticoagulants or decellularized allo/xenografts that tend to quickly calcify in younger patients. Valve replacements containing cells able to grow and repair damaged valve tissue could positively impact patient morbidity. However, matricellular cues associated with healthy tissue deposition by the resident aortic valvular interstitial cells (VICs) are still not well understood. This thesis aims to study the effects and underlying mechanisms of matrix elasticity and biochemical cues (e.g., bound integrins or ...


Poly(Ethylene Glycol) Based Biomaterial Platforms For Guiding Cell Behavior Through Control Of Presentation And Release Of Bioactive, Therapeutic Proteins., Joshua Daniel Mccall Jan 2012

Poly(Ethylene Glycol) Based Biomaterial Platforms For Guiding Cell Behavior Through Control Of Presentation And Release Of Bioactive, Therapeutic Proteins., Joshua Daniel Mccall

Chemical & Biological Engineering Graduate Theses & Dissertations

Poly(ethylene glycol) (PEG) based biomaterials offer a number of advantages for applications in biomedical technology, including drug delivery and tissue engineering. PEG is notable for both its hydrophilicity and bioinert properties, and is widely used to create hydrogels used for 3D cell culture. There is growing interest in strategies to introduce biological functionality into PEG-based materials, in order to develop platforms to study the complex biochemical and biomechanical cues that govern cell behavior in physiologically relevant context. This thesis explores photopolymerization conditions for hydrogel synthesis that maintain a high degree of bioactivity for proteins in-situ. Such reactions are then ...


Development And Implementation Of Clickable Amino Acids, Kenneth Christopher Koehler Jan 2012

Development And Implementation Of Clickable Amino Acids, Kenneth Christopher Koehler

Chemical & Biological Engineering Graduate Theses & Dissertations

Peptides present an enormous potential for therapeutic and material science applications. However, in their native format, due to a limited number of chemical handles useful for structural manipulation to address stability issues and facilitate inclusion into other materials, the ability to completely access and implement the potential wealth peptides have to offer is restricted. The overall objective of this thesis endeavored to expand the utility of peptides through the development of synthetic amino acids compatible with click chemistry. Specifically, this work investigated the development of maleimide and furan derivatized amino acids for implementation in the Michael addition and Diels-Alder click ...


Fundamental Characterization Of Photodegradable Hydrogels: Spatiotemporal Control Of The Cellular Microenvironment, Mark William Tibbitt Jan 2012

Fundamental Characterization Of Photodegradable Hydrogels: Spatiotemporal Control Of The Cellular Microenvironment, Mark William Tibbitt

Chemical & Biological Engineering Graduate Theses & Dissertations

Synthetic hydrogels are an attractive class of materials for the design of well-defined cell culture platforms to better understand how cells receive and integrate signals present in the extracellular environment. Within this class, responsive hydrogels have emerged to investigate questions as to how cells sense and respond to dynamic changes in the mechanical and biochemical nature of the cell niche. To complement this growing body of research, this thesis aimed to develop photoresponsive, synthetic hydrogels that enable experimenters to explore how spatiotemporally varying cues from the extracellular matric influence biological function in real time. Specifically, cytocompatible, chain and step polymerized ...


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 ...


Phototunable Click-Based Hydrogels For 3d Cell Culture: Dynamic Biochemical And Biomechanical Tailorability Of The Cell Niche, Cole Alexander Deforest Jan 2011

Phototunable Click-Based Hydrogels For 3d Cell Culture: Dynamic Biochemical And Biomechanical Tailorability Of The Cell Niche, Cole Alexander Deforest

Chemical & Biological Engineering Graduate Theses & Dissertations

To better understand how cells receive and respond to signals presented by their external surroundings, polymer-based hydrogels have emerged as highly tailorable constructs for assaying cell function in well-defined microenvironments where the effects of user-dictated functionalities can be individually probed. This thesis research aimed to develop synthetic strategies to create and modify 3D cell culture platforms that permit researchers to explore in real time how cell-material interactions influence important biological function. Specifically, cytocompatible hydrogels were formed via a novel strain-promoted azide-alkyne cycloaddition reaction between a tetrafunctional poly(ethylene glycol) and a difunctional enzymatically-degradable peptide sequence, which enabled cell-mediated active remodeling ...


Development And Characterization Of Porous And Patterned Hydrogel Scaffolds For Cardiac Muscle Tissue Engineering, Stephanie Marie Lanasa Jan 2010

Development And Characterization Of Porous And Patterned Hydrogel Scaffolds For Cardiac Muscle Tissue Engineering, Stephanie Marie Lanasa

Chemical & Biological Engineering Graduate Theses & Dissertations

Coronary heart disease has become increasingly prevalent in the U.S. and worldwide, and now affects over one million Americans annually. The damaged tissue that results from cardiac injury lacks the ability to regenerate, but no therapies exist to regenerate heart tissue. Tissue engineering is one promising method through which cardiac tissue could be regenerated. This research focuses on developing a tissue engineered hydrogel scaffold using a design regimen that facilitates nutrient transport, tensile properties, and cardiomyocyte adhesion and alignment. A porous structure incorporated into the bulk of the scaffold was selected as a means to enhance nutrient transport. Variations ...