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Full-Text Articles in Biomedical Engineering and Bioengineering

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 ...


Nanoscale Stiffness Cues Influence Valvular Interstitial Cell Activation To Myofibroblasts, Michaela Wenning Jan 2019

Nanoscale Stiffness Cues Influence Valvular Interstitial Cell Activation To Myofibroblasts, Michaela Wenning

Undergraduate Honors Theses

Surgery is currently the primary treatment option for aortic valve stenosis (AVS) patients, many of whom are ineligible for surgery and are left untreated. AVS is progression is known to differ between males and females, and an understanding of sex-specific mechanisms of disease progression is imperative in developing accurate treatment options for men and women. The development of a nonsurgical therapy for AVS patients requires a deeper understanding of the molecular and cellular mechanisms of AVS progression. Currently, the role of calcium phosphate nanoparticles detected in the aortic valve during early stages of AVS in influencing disease progression and valvular ...


Thermal Fusion For Sutureless Closure: Devices, Composition, Methods, Eric Anthony Kramer Jan 2018

Thermal Fusion For Sutureless Closure: Devices, Composition, Methods, Eric Anthony Kramer

Mechanical Engineering Graduate Theses & Dissertations

As minimally invasive surgical techniques progress, the demand for reliable ligation is pronounced. The surgical advantages of energy-based vessel sealing exceed those of traditional, compression-based ligatures in procedures sensitive to duration, foreign bodies, and recovery time alike. While the use of energy-based devices to seal or transect vasculature and connective tissue bundles is widespread, the breadth of heating strategies and energy dosimetry used between devices underscores an uncertainty as to the molecular nature of the sealing mechanism and induced tissue bond. Further, energy-based techniques (e.g., tissue “fusion” or tissue “welding”) exhibit promise for the closure, repair and functional recovery ...


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 ...


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 ...


Application Of Advances In Synthetic Biology To Modular Megasynthase Design And Scalable Combinatorial Biosynthesis, William Clifford Grau Jan 2018

Application Of Advances In Synthetic Biology To Modular Megasynthase Design And Scalable Combinatorial Biosynthesis, William Clifford Grau

Chemistry & Biochemistry Graduate Theses & Dissertations (1986-2018)

The diversity in structure and biological activity of natural products has long captured the imagination of chemists and molecular biologists alike. Natural products are synthesized by elaborate secondary metabolic pathways or enzymes. For example, modular megasynthases such as Type I Polyketide Synthases (PKSs), Non-ribosomal Peptide Synthetases (NRPSs), and PKS-NRPS hybrids, produce an array of quintessential natural products. The apparent modularity, defined architecture, and predictable chemistry of modular megasynthases make them especially attractive for combinatorial biosynthesis, which has long been a focus of biotechnology. Combinatorial biosynthetic libraries are of particular interest due to the high value of many natural products and ...


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 ...


Engineering The Phospholipid Monolayer On Fluorocarbon, Hydrocarbon, And Liquid Crystal Nanodroplets For Applications In Biosensing, Rajarshi Chattaraj Jan 2018

Engineering The Phospholipid Monolayer On Fluorocarbon, Hydrocarbon, And Liquid Crystal Nanodroplets For Applications In Biosensing, Rajarshi Chattaraj

Mechanical Engineering Graduate Theses & Dissertations

Nanodroplets (NDs) are liquid-in-liquid dispersions of ~100-800 nm size range that are often stabilized by a shell of lipids, polymer, proteins, or surfactants. NDs have been explored for a variety of biomedical applications, mostly involving drug formulation and delivery. However, the unique properties of encapsulated liquids, and the effects of interfacial chemistry on these properties, makes NDs potentially powerful candidates for new biosensing technologies. This dissertation explores different oil-in-water or fluorocarbon-in-water ND systems for in-solution sensing of biomarkers as both a platform for diagnostic assays and as a precursor to in vivo biosensing. Nanodroplets, because of their size, provide a ...


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 ...


Enzymatically Degradable Poly(Ethylene Glycol) Hydrogels For Diverse Tissue Engineering Applications And For The Study Of The Foreign Body Response, Luke Daniel Amer Jan 2016

Enzymatically Degradable Poly(Ethylene Glycol) Hydrogels For Diverse Tissue Engineering Applications And For The Study Of The Foreign Body Response, Luke Daniel Amer

Chemical Engineering Graduate Theses & Dissertations

The field of tissue engineering aims to create replacements for diseased or damaged tissues which restore function and integrate with the host. Poly(ethylene glycol) (PEG) hydrogels are promising materials for the delivery of cells for tissue engineering applications, however, as with all synthetic materials, they elicit a foreign body response (FBR) upon implantation. Generally, the FBR begins with an initial inflammatory response and ends with the encapsulation of the implant in an avascular fibrous capsule. The harsh environment present during the FBR may harm encapsulated cells and impair integration into the host, ultimately reducing the efficacy of tissue engineering ...


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 ...


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 ...


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 ...


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 ...


Synthetic Peptide Design For Functionalized Hydrogels: Development Of Cellularly Responsive Drug Delivery Platforms And Cyclic, Multivalent Peptide Derivatives Using Radical-Mediated Thiol-Ene/Thiol-Yne Chemistries, Alex Arthur Aimetti Jan 2010

Synthetic Peptide Design For Functionalized Hydrogels: Development Of Cellularly Responsive Drug Delivery Platforms And Cyclic, Multivalent Peptide Derivatives Using Radical-Mediated Thiol-Ene/Thiol-Yne Chemistries, Alex Arthur Aimetti

Chemical & Biological Engineering Graduate Theses & Dissertations

Poly(ethylene glycol) (PEG)-based hydrogels represent a class of biomaterials with a growing interest for their application in numerous fields, such as drug delivery and regenerative medicine. PEG is commonly used in these applications due to its hydrophilic and bioinert properties. Additionally, peptides have been successfully incorporated within PEG hydrogels to serve as biological functionalities within a synthetic polymer platform. Peptide-functionalized PEG hydrogels have been shown to act as extracellular matrix (ECM)-mimics capable of enhancing cell survival, function, and differentiation. Alternatively, peptides can be designed to degrade in recognition of highly specific, cell-secreted proteases. This phenomenon has been ...