Biomedical Engineering and Bioengineering Commons^™

Electrophysiology Of Basal Ganglia (Bg) Circuitry And Dystonia As A Model Of Motor Control Dysfunction, Deepak Kumbhare

Theses and Dissertations

The basal ganglia (BG) is a complex set of heavily interconnected nuclei located in the central part of the brain that receives inputs from the several areas of the cortex and projects via the thalamus back to the prefrontal and motor cortical areas. Despite playing a significant part in multiple brain functions, the physiology of the BG and associated disorders like dystonia remain poorly understood. Dystonia is a devastating condition characterized by ineffective, twisting movements, prolonged co-contractions and contorted postures. Evidences suggest that it occurs due to abnormal discharge patterning in BG-thalamocortocal (BGTC) circuitry. The central purpose of this study …

Novel Small Airway Model Using Electrospun Decellularized Lung Extracellular Matrix, Bethany M. Young

Theses and Dissertations

Chronic respiratory diseases affects many people worldwide with little known about the mechanisms diving the pathology, making it difficult to find a cure. Improving the understanding of smooth muscle and extracellular matrix (ECM) interaction is key to developing a remedy to this leading cause of death. With currently no relevant or controllable in vivo or in vitro model to investigate diseased and normal interactions of small airway components, the development of a physiologically relevant in vitro model with comparable cell attachment, signaling, and organization is necessary to develop new treatments for airway disease. The goal of this study is to …

Improved Capability Of A Computational Foot/Ankle Model Using Artificial Neural Networks, Ruchi D. Chande

Theses and Dissertations

Computational joint models provide insight into the biomechanical function of human joints. Through both deformable and rigid body modeling, the structure-function relationship governing joint behavior is better understood, and subsequently, knowledge regarding normal, diseased, and/or injured function is garnered. Given the utility of these computational models, it is imperative to supply them with appropriate inputs such that model function is representative of true joint function. In these models, Magnetic Resonance Imaging (MRI) or Computerized Tomography (CT) scans and literature inform the bony anatomy and mechanical properties of muscle and ligamentous tissues, respectively. In the case of the latter, literature reports …

Characterization Of Poly(Dimethylsiloxane) Blends And Fabrication Of Soft Micropillar Arrays For Force Detection, Thomas J. Petet Jr

Theses and Dissertations

Diseases involving fibrosis cause tens of thousands of deaths per year in the US alone. These diseases are characterized by a large amount of extracellular matrix, causing stiff abnormal tissues that may not function correctly. To take steps towards curing these diseases, a fundamental understanding of how cells interact with their substrate and how mechanical forces alter signaling pathways is vital. Studying the mechanobiology of cells and the interaction between a cell and its extracellular matrix can help explain the mechanisms behind stem cell differentiation, cell migration, and metastasis. Due to the correlation between force, extracellular matrix assembly, and substrate …

Role Of E-Cadherin Force In The Spatial Regulation Of Cell Proliferation, Abhinav Mohan

Theses and Dissertations

Cell proliferation and contact inhibition play a major role in maintaining epithelial cell homeostasis. A hallmark of epithelial cells is strong cell-cell junctions. These junctions include E-Cadherin, a type of adherens junction that is critical for both barrier function and contact inhibition. Prior experiments by other groups have shown that adherens junctions are subject to mechanical tension. Externally applied forces (e.g. stretch) results in changes in E-Cadherin forces that coordinate proliferation. My current work tests the hypothesis that E-Cadherin forces mediate the spatial regulation of cell proliferation even in the absence of externally applied forces.

An Investigation Of Kinetic Visual Biofeedback On Dynamic Stance Symmetry, Trisha J. Massenzo

Theses and Dissertations

The intent of the following research is to utilize task-specific, constraint-induced therapies and apply towards dynamic training for symmetrical balance. Modifications to an elliptical trainer were made to both measure weight distributions during dynamic stance as well as provide kinetic biofeedback through a man-machine interface. Following a review of the background, which includes research from several decades that are seminal to current studies, a design review is discussed to cover the design of the modified elliptical (Chapter 2).

An initial study was conducted in a healthy sample population in order to determine the best visual biofeedback representation by comparing different …

A Computational Study Of Curvature In The Outflow Graft Of A Continuous Flow Left Ventricular Assist Device, Laura Patterson

Theses and Dissertations

Left ventricular assist devices (LVADs) are an increasingly utilized therapy for end-stage heart failure. Thrombosis within the graft from the pump to the aorta has been documented, but is poorly researched. This study examines the effect of graft geometry, as measured by radius of curvature, bend angle, and diameter, on thrombogenic flow patterns within the graft for a range of flow conditions. It also examines the effect blood properties, including viscosity and density, on these flow patterns. The results indicated that radius of curvature had a powerful effect on thrombogenic flow patterns. Flowrate and bend angle were also influential. The …

Intracellular Ros Mediates Gas Plasma-Facilitated Cellular Transfection In 2d And 3d Cultures, Dehui Xu, Biqing Wang, Yujing Xu, Zeyu Chen, Qinjie Cui, Yanjie Yang, Hailan Chen, Michael G. Kong

Bioelectrics Publications

This study reports the potential of cold atmospheric plasma (CAP) as a versatile tool for delivering oligonucleotides into mammalian cells. Compared to lipofection and electroporation methods, plasma transfection showed a better uptake efficiency and less cell death in the transfection of oligonucleotides. We demonstrated that the level of extracellular aqueous reactive oxygen species (ROS) produced by gas plasma is correlated with the uptake efficiency and that this is achieved through an increase of intracellular ROS levels and the resulting increase in cell membrane permeability. This finding was supported by the use of ROS scavengers, which reduced CAP-based uptake efficiency. In …

Biom 3110: Medical Physiology (Syllabus), Bradford D. Pendley

Biomedical Engineering Syllabi Archive

Course Description: Basic principles of human physiology and how these are applied in medicine and biomedical engineering problem and devices; physiological principles using appropriate mathematical and engineering models to construct an understanding of how the body works as an integrated system.

Biom 4110/6110: The Science Of Medicine (Syllabus), Bradford D. Pendley

Biomedical Engineering Syllabi Archive

Course Description: Integration of fundamental principles from physics, chemistry, biology and mathematics, and applications of these principles to solve problems in medicine.

Microbubble Assisted Polyhydroxybutyrate Production In Escherichia Coli, Kadriye Innan, Fulya Ay Sal, Asif Rahman, Ryan J. Putman, Foster A. Agblevor, Charles D. Miller

Biological Engineering Faculty Publications

Background

One of the potential limitations of large scale aerobic Escherichia coli fermentation is the need for increased dissolved oxygen for culture growth and bioproduct generation. As culture density increases the poor solubility of oxygen in water becomes one of the limiting factors for cell growth and product formation. A potential solution is to use a microbubble dispersion (MBD) generating device to reduce the diameter and increase the surface area of sparged bubbles in the fermentor. In this study, a recombinantE. coli strain was used to produce polyhydroxybutyrate (PHB) under conventional and MBD aerobic fermentation conditions.

Results

In conventional …

Rational Design Of Rama-Labeled Nanoparticles For A Dual-Modaility, Light Scattering Immunoassay On A Polystyrene Substrate, Nathan D. Israelsen, Donald Wooley, Cynthia Hanson, Elizabeth Vargis

Biological Engineering Faculty Publications

Background: Surface-enhanced Raman scattering (SERS) is a powerful light scattering technique that can be used for sensitive immunoassay development and cell labeling. A major obstacle to using SERS is the complexity of fabricating SERS probes since they require nanoscale characterization and optical uniformity. The light scattering response of SERS probes may also be modulated by the substrate used for SERS analysis. A typical SERS substrate such as quartz can be expensive. Polystyrene is a cheaper substrate option but can decrease the SERS response due to interfering Raman emission peaks and high background fluorescence. The goal of this research is to …

Bioactive Poly(Beta-Amino Ester) Biomaterials For Treatment Of Infection And Oxidative Stress, Andrew L. Lakes

Theses and Dissertations--Chemical and Materials Engineering

Polymers have deep roots as drug delivery tools, and are widely used in clinical to private settings. Currently, however, numerous traditional therapies exist which may be improved through use of polymeric biomaterials. Through our work with infectious and oxidative stress disease prevention and treatment, we aimed to develop application driven, enhanced therapies utilizing new classes of polymers synthesized in-house. Applying biodegradable poly(β-amino ester) (PBAE) polymers, covalent-addition of bioactive substrates to these PBAEs avoided certain pitfalls of free-loaded and non-degradable drug delivery systems. Further, through variation of polymer ingredients and conditions, we were able to tune degradation rates, release profiles, cellular …

Synthesis And Characterization Of Antioxidant Conjugated Poly(Βeta-Amino Ester) Micro/Nanogels For The Suppression Of Oxidative Stress, Prachi Gupta

Theses and Dissertations--Chemical and Materials Engineering

Oxidative stress is a pathophysiological condition defined by an increased production of reactive oxygen species (ROS), which can result in the growth arrest of cells followed by cell disintegration or necrosis. A number of small molecule antioxidants (e.g. curcumin, quercetin and resveratrol) are capable of directly scavenging ROS, thereby short-circuiting the self-propagating oxidative stress state. However, poor solubility and rapid 1^st pass metabolism results in overall low bioavailability and acts as a barrier for its use as a drug to suppress oxidative stress efficiently.

To overcome this limitation, these small molecule antioxidants were covalently conjugated into poly(β-amino ester) (PβAE) …

Modeling Early Stage Bone Regeneration With Biomimetic Electrospun Fibrinogen Nanofibers And Adipose-Derived Mesenchymal Stem Cells, Michael P. Francis, Yas M. Moghaddam-White, Patrick C. Sachs, Matthew J. Beckman, Stephen M. Chen, Gary L. Bowlin, Lynne W. Elmore, Shawn E. Holt

School of Medical Diagnostics & Translational Sciences Publications

The key events of the earliest stages of bone regeneration have been described in vivo although not yet modeled in an in vitro environment, where mechanistic cell-matrix-growth factor interactions can be more effectively studied. Here, we explore an early-stage bone regeneration model where the ability of electrospun fibrinogen (Fg) nanofibers to regulate osteoblastogenesis between distinct mesenchymal stem cells populations is assessed. Electrospun scaffolds of Fg, polydioxanone (PDO), and a Fg:PDO blend were seeded with adipose-derived mesenchymal stem cells (ASCs) and grown for 7-21 days in osteogenic differentiation media or control growth media. Scaffolds were analyzed weekly for histologic and molecular …

Accessible Bioprinting: Adaptation Of A Low-Cost 3d-Printer For Precise Cell Placement And Stem Cell Differentiation, John A. Reid, Peter A. Mollica, Garett D. Johnson, Roy C. Ogle, Robert D. Bruno, Patrick C. Sachs

School of Medical Diagnostics & Translational Sciences Publications

The precision and repeatability offered by computer-aided design and computer-numerically controlled techniques in biofabrication processes is quickly becoming an industry standard. However, many hurdles still exist before these techniques can be used in research laboratories for cellular and molecular biology applications. Extrusion-based bioprinting systems have been characterized by high development costs, injector clogging, difficulty achieving small cell number deposits, decreased cell viability, and altered cell function post-printing. To circumvent the high-price barrier to entry of conventional bioprinters, we designed and 3D printed components for the adaptation of an inexpensive 'off-the-shelf' commercially available 3D printer. We also demonstrate via goal based …

Categorizing Fetal Heart Rate Variability With And Without Visual Aids, Amanda J. Ashdown, Mark W. Scerbo, Lee A. Belfore Ii, Stephen S. Davis, Alfred Z. Abuhamad

Psychology Faculty Publications

Objective This study examined the ability of clinicians to correctly categorize images of fetal heart rate (FHR) variability with and without the use of exemplars.

Study Design A sample of 33 labor and delivery clinicians inspected static FHR images and categorized them into one of four categories defined by the National Institute of Child Health and Human Development (NICHD) based on the amount of variability within absent, minimal, moderate, or marked ranges. Participants took part in three conditions: two in which they used exemplars representing FHR variability near the center or near the boundaries of each range, and a third …

A Software Application For Cardiac-Gated Computerized Tomography Scanning, Stephen Caldwell, Trevor Engelsman

Williams Honors College, Honors Research Projects

Computerized tomography (CT) scans are a common clinical imaging procedure used worldwide. Operating in the X-Ray spectrum, these machines rotate scanners around a stationary body in order to compile two-dimensional images into a unified three-dimensional image. With adjustment to scan frequency and intensity, internal features such as muscles, organs, and tendons can easily be viewed. However, the heart has long evaded CT use due to its near-constant motion. Recently, cardiac-gated scans have entered the market as a technique to image the heart at a specific moment in time when it is nearly still - the quiescent period. Occurring during rapid …

Characterization Of Fibrin Matrix Incorporated Electrospun Polycaprolactone Scaffold, Cho Yi Wong

Theses and Dissertations

Specific objective: Guided tissue regeneration (GTR) aims to regenerate the lost attachment apparatus caused by periodontal disease through the use of a barrier membrane. For the GTR procedures to be successful, barrier membranes are required to be present at the surgical site for an extended period of time (weeks to months). Synthetic membranes have the advantage of prolonged presence in a wound site; however, they do not actively contribute to wound healing. Biologic membranes are recognized by the host tissue and participate in wound healing but have the disadvantage of early resorption. Therefore, the goal of this study is …

The Protective Role Of Mlcp-Mediated Erm Dephosphorylation In Endotoxin-Induced Lung Injury In Vitro And In Vivo, Anita Kovacs-Kasa, Boris A. Gorshkov, Kyung-Mi Kim, Sanjiv Kumar, Stephen M. Black, David J. Fulton, Christiana Dimitropoulou, John D. Catravas, Alexander D. Verin

Bioelectrics Publications

The goal of this study was to investigate the role of MLC phosphatase (MLCP) in a LPS model of acute lung injury (ALI). We demonstrate that ectopic expression of a constitutively-active (C/A) MLCP regulatory subunit (MYPT1) attenuates the ability of LPS to increase endothelial (EC) permeability. Down-regulation of MYPT1 exacerbates LPS-induced expression of ICAM1 suggesting an anti-inflammatory role of MLCP. To determine whether MLCP contributes to LPS-induced ALI in vivo, we utilized a nanoparticle DNA delivery method to specifically target lung EC. Expression of a C/A MYPT1 reduced LPS-induced lung inflammation and vascular permeability. Further, increased expression of the …