Biomedical Engineering and Bioengineering Commons^™

A Microfluidic Tissue Array (Μfta) For Personalized Medicine Using Tumor Biopsies, A.H. R. Ahmed

Dissertations and Theses

Cancer is recognized as a complex disease with both genetic and epigenetic drivers that can vary from one individual to another. While very early research into cancer treated it as a clonal malfunction that could originate from as small as a single deregulated cell, the disease itself manifests itself with several more complexities beyond tumorigenic cells only. The tumor microenvironment itself – from the extracellular matrix to stromal cells - cooperate with tumor cells in a symbiotic manner towards metastatic progression. Clinical studies have provided more information regarding the degree of individualization possible, such that patients with similar genetic makeup …

Controlled Migration Of Retinal Progenitor Cells Within Electro-Chemotactic Fields, Shawn Mishra

Dissertations and Theses

Vision loss in retinal degenerative diseases is overwhelmingly attributed to damage and death of retinal photoreceptor cells. Studies in mouse retina have suggested that transplantation of isolated post-natal or stem cell-derived retinal progenitor cells (RPCs) to replace apoptotic or damaged photoreceptors may be a novel approach to restore vision. Thus far, outcomes project that the amount of restored visual response depends upon the migration of transplanted cells from insertion in the sub-retinal space to the outer nuclear layer (ONL). However, transplantation efficiency is exceedingly low – ~5% cells transplanted enter the retina – directly limiting the efficacy of the treatments. …

Neuron-Glial (Ng) Interactions: A Microfluidic Examination Of Ng Emergent Responses For Repair, Tanya Singh

Dissertations and Theses

Neuron-glia communication is crucial to the development, plasticity, and repair of the nervous system (NS). While neurons are well known to conduct electrical impulses that transfer biological information and stimuli throughout the NS, our understanding of the roles of glia continues to evolve from when the cells were largely believed to act solely for neuronal support. Recent decades of research has shown that glia can alter metabolism, conduct impulses and change phenotype for NS repair. NG interactions have, thereby, become heavily researched in varied areas of biomedical engineering, including embryogenesis, neural regeneration, growth, and intracellular synaptic activity. However, while NG …

Modification Of Lipid Microenvironments On Solid Support Structures For Use In Transmembrane Protein Assays, William J. Houlihan

Dissertations and Theses

Gamma-Secretase (γ-secretase) is a transmembrane protease of increasing interest, which has been shown to have significant connections to both cancer and Alzheimer’s disease. γ-secretase cleaves both Notch-1, a transmembrane signaling protein, and Amyloid precursor protein (APP), a transmembrane protein whose cleavage may result in the formation of β-amyloid plaques in the brain. Notch-1 and APP are widely studied proteins that have substantial impacts on the development and proliferation of cancer and Alzheimer’s disease, respectively. Notch-1 partakes in the signaling of apoptosis in damaged and mutated cells, thus its cleavage by γ-secretase within the plasma membrane has ramifications on cell growth …

Translational Modeling Of Non-Invasive Electrical Stimulation, Dennis Quangvinh Truong

Dissertations and Theses

Seminal work in the early 2000’s demonstrated the effect of low amplitude non-invasive electrical stimulation in people using neurophysiological measures (motor evoked potentials, MEPs). Clinical applications of transcranial Direct Current Stimulation (tDCS) have since proliferated, though the mechanisms are not fully understood. Efforts to refine the technique to improve results are on-going as are mechanistic studies both in vivo and in vitro. Volume conduction models are being applied to these areas of research, especially in the design and analysis of clinical montages. However, additional research on the parameterization of models remains.

In this dissertation, Finite Element Method (FEM) models of …

Effect Of Hypoxia On Spontaneous Neural Activity In The Cortex Of Neonate Mouse Pups, Krithikka Ravi Ms

Dissertations and Theses

Hypoxia caused by inadequate oxygenation has profound effects on the normal functioning of the brain in mammals. Acute or chronic hypoxic insults occur in the brain depending on the duration of hypoxic exposure. Hypoxia is known to occur in the human womb and exerts adverse effects on the developing fetus. Most of the ongoing research on hypoxia is performed on rodent brain slice taken from various brain regions using intracellular recording. Extensive work has been carried out to understand the effects of chronic hypoxia on the developing nervous system, specifically during intrauterine development. However, effects of acute hypoxia occurring perinatally, …

Intensification Of Gas Absorption In A Downward Flow Microbubble Bioreactor, Manizheh Ansari

Dissertations and Theses

Bioreactors are of interest for value-upgrading of stranded or waste industrial gases, such as CO, CH₄, or syngas. Process economics requires reduction of reactor cost and size while maintaining high production rate via rapid delivery of gas feedstock to the liquid phase which in turn requires a high volumetric mass transfer rate (). One strategy to achieve this goal is to increase interfacial area density, a, to >3000 m² m^-3, while minimizing use of energy. Here we show a novel reactor column design that uses a micro-jet array to break feedstock at ambient pressure …

Collective Behavior Of Drosophila Melanogaster Neural Progenitor And Imaginal Disc Cells Within Controlled Microenvironments, Caroline D. Pena

Dissertations and Theses

Regenerative therapies for the damaged visual system have introduced stem-derived cells to recapitulate developmental processes and initiate functional regeneration in different components of the eye. The developing visual system in Drosophila Melanogaster offers a model in which to analyze the associated processes in retinogenesis. The optic nerve is critical to vision and is developmentally preceded in Drosophila by a structure called the Optic Stalk (OS). Collective migration of neural and retinal progenitor cells (RPCs) from the developing brain lobes (DBL) to the Imaginal Disc (ID), through the OS, is a fundamental part of regenerative strategies in retina. Developmental signals governing …