Biomedical Engineering and Bioengineering Commons^™

Towards An In Vitro Model Of Testing Osteoblast Cellular Function In Contact With Various Surfaces, Raheleh Miralami

Theses & Dissertations

Past studies have shown that the success of total joint replacements depends on the biocompatibility of orthopaedic materials, which can be improved by modifying the implant surface. However, the exact roles of these modifications and their effective mechanisms are poorly understood. The objective of this study was to develop and evaluate a model system to investigate the impact of nano-structured surfaces, produced by the ion beam-assisted deposition (IBAD) technique, on biomarkers of osteointegration using an in vitro model. The IBAD technique was employed to deposit zirconium oxide (ZrO₂), Titanium oxide (TiO₂), and Titanium (Ti) nano-films on …

Manganese-Enhanced Magnetic Resonance Imaging: Overview And Central Nervous System Applications With A Focus On Neurodegeneration, Ryan A. Cloyd, Shon A. Koren, Jose F. Abisambra

Physiology Faculty Publications

Manganese-enhanced magnetic resonance imaging (MEMRI) rose to prominence in the 1990s as a sensitive approach to high contrast imaging. Following the discovery of manganese conductance through calcium-permeable channels, MEMRI applications expanded to include functional imaging in the central nervous system (CNS) and other body systems. MEMRI has since been employed in the investigation of physiology in many animal models and in humans. Here, we review historical perspectives that follow the evolution of applied MRI research into MEMRI with particular focus on its potential toxicity. Furthermore, we discuss the more current in vivo investigative uses of MEMRI in CNS investigations and …

Distinct White Matter Changes Associated With Cerebrospinal Fluid Amyloid-Β1-42 And Hypertension, Omar M. Al-Janabi, Christopher A. Brown, Ahmed A. Bahrani, Erin L. Abner, Justin M. Barber, Brian T. Gold, Larry B. Goldstein, Richard R. Murphy, Peter T. Nelson, Nathan F. Johnson, Leslie M. Shaw, Charles D. Smith, John Q. Trojanowski, Donna M. Wilcock, Gregory A. Jicha

Sanders-Brown Center on Aging Faculty Publications

BACKGROUND: Alzheimer's disease (AD) pathology and hypertension (HTN) are risk factors for development of white matter (WM) alterations and might be independently associated with these alterations in older adults.

OBJECTIVE: To evaluate the independent and synergistic effects of HTN and AD pathology on WM alterations.

METHODS: Clinical measures of cerebrovascular disease risk were collected from 62 participants in University of Kentucky Alzheimer's Disease Center studies who also had cerebrospinal fluid (CSF) sampling and MRI brain scans. CSF Aβ_1-42 levels were measured as a marker of AD, and fluid-attenuated inversion recovery imaging and diffusion tensor imaging were obtained to assess …

Demonstration Of Monolithic-Silicon Carbide (Sic) Neural Devices, Evans K. Bernardin

USF Tampa Graduate Theses and Dissertations

Brain Machine Interfaces (BMI) provide a communication pathway between the electrical conducting units of the brain (neurons) and external devices. BMI technology may provide improved neurological and physiological functions to patients suffering from disabilities due to damaged nervous systems. Unfortunately, microelectrodes used in Intracortical Neural Interfaces (INI), a subset of the BMI device family, have yet to demonstrate long-term in vivo performance due to material, mechanical and electrical failures. Many state-of-the-art INI devices are constructed using stacks of multiple materials, such as silicon (Si), titanium (Ti), platinum (Pt), parylene C, and polyimide. Not only must each material tolerate the biological …

In Vivo Brainstem Imaging In Alzheimer’S Disease: Potential For Biomarker Development, David J. Braun, Linda J. Van Eldik

Neuroscience Faculty Publications

The dearth of effective treatments for Alzheimer’s disease (AD) is one of the largest public health issues worldwide, costing hundreds of billions of dollars per year. From a therapeutic standpoint, research efforts to date have met with strikingly little clinical success. One major issue is that trials begin after substantial pathological change has occurred, and it is increasingly clear that the most effective treatment regimens will need to be administered earlier in the disease process. In order to identify individuals within the long preclinical phase of AD who are likely to progress to dementia, improvements are required in biomarker development. …

Neuroimaging Biomarkers Of Mtor Inhibition On Vascular And Metabolic Functions In Aging Brain And Alzheimer’S Disease, Jennifer Lee, Lucille M. Yanckello, David Ma, Jared D. Hoffman, Ishita Parikh, Scott Thalman, Bjoern Bauer, Anika M. S. Hartz, Fahmeed Hyder, Ai-Ling Lin

Pharmacology and Nutritional Sciences Faculty Publications

The mechanistic target of rapamycin (mTOR) is a nutrient sensor of eukaryotic cells. Inhibition of mechanistic mTOR signaling can increase life and health span in various species via interventions that include rapamycin and caloric restriction (CR). In the central nervous system, mTOR inhibition demonstrates neuroprotective patterns in aging and Alzheimer’s disease (AD) by preserving mitochondrial function and reducing amyloid beta retention. However, the effects of mTOR inhibition for in vivo brain physiology remain largely unknown. Here, we review recent findings of in vivo metabolic and vascular measures using non-invasive, multimodal neuroimaging methods in rodent models for brain aging and AD. …

Artificial Gravity As A Countermeasure To The Cardiovascular Deconditioning Of Spaceflight: Gender Perspectives, Joyce M. Evans, Charles F. Knapp, Nandu Goswami

Biomedical Engineering Faculty Publications

Space flight-induced physiological deconditioning resulting from decreased gravitational input, decreased plasma volume, and disruption of regulatory mechanisms is a significant problem in returning astronauts as well as in normal aging. Here we review effects of a promising countermeasure on cardiovascular systems of healthy men and women undergoing Earth-based models of space-flight. This countermeasure is produced by a centrifuge and called artificial gravity (AG). Numerous studies have determined that AG improves orthostatic tolerance (as assessed by various protocols) of healthy ambulatory men, of men deconditioned by bed rest or by immersion (both wet and dry) and, in one case, following spaceflight. …

Preparation And Characterization Of Functionalized Heparin-Loaded Poly-Ɛ-Caprolactone Fibrous Mats To Prevent Infection With Human Papillomaviruses, Daniela Gonzalez, Jorge Ragusa, Peter C. Angeletti, Gustavo F. Larsen

Department of Chemical and Biomolecular Engineering: Faculty Publications

In this study, heparin-loaded poly-ε-caprolactone (PCL) fibrous mats were prepared and characterized based on their physical, cytotoxic, thermal, and biological properties. The main objective of the work described here was to test the hypothesis that incorporation of heparin into a PCL carrier could serve as bio-compatible material capable of inhibiting Human Papillomavirus (HPV) infection. The idea of firmly anchoring heparin to capture soluble virus, vs. a slow heparin release to inhibit a virus in solution was tested. Thus, one material was produced via conventional heparin matrix encapsulation and electrohydrodynamic fiber processing in one step. A second type of material was …

Developmental Steps For A Functional Three-Dimensional Cell Culture System For The Study Of Asymmetrical Division Of Neural Stem Cells, Martina Zamponi

Biomedical Engineering Theses & Dissertations

Stem cells are a cell type present during and following development, which possess self- renewal properties, as well as the ability to differentiate into specific cells. Asymmetrical division is the cellular process that allows stem cells to produce one differentiated and one un-differentiated daughter cell during the same mitotic event. Insights in the molecular mechanisms of such process are minimal, due to the absence of effective methods for its targeted study. Currently, traditional methods of investigation include monolayer cell culture and animal models. The first poses structural limitations to the accurate representation of human tissue and cell structures, while animal …

Metabolic Patterning On A Chip: Towards In Vitro Liver Zonation Of Primary Rat And Human Hepatocytes, Young Bok (Abraham) Kang, Jinsu Eo, Safak Mert, Martin L. Yarmush, O. Berk Usta

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

An important number of healthy and diseased tissues shows spatial variations in their metabolic capacities across the tissue. The liver is a prime example of such heterogeneity where the gradual changes in various metabolic activities across the liver sinusoid is termed as “zonation” of the liver. Here, we introduce the Metabolic Patterning on a Chip (MPOC) platform capable of dynamically creating metabolic patterns across the length of a microchamber of liver tissue via actively enforced gradients of various metabolic modulators such as hormones and inducers. Using this platform, we were able to create continuous liver tissues of both rat and …

Submandibular Mechanical Stimulation Of Upper Airway Muscles To Treat Obstructive Sleep Apnea, Ferhat Erdogan

Dissertations

The extrinsic tongue muscles are activated in coordination with pharyngeal muscles to keep a patent airway during respiration in wakefulness and sleep. The activity of genioglossus, the primary tongue-protruding muscle playing an important role in this coordination, is known to be modulated by several reflex pathways mediated through the mechanoreceptors of the upper airways. The main objective is to investigate the effectiveness of activating these reflex pathways with mechanical stimulations, for the long-term goal of improving the upper airway patency during disordered breathing in sleep. The genioglossus response is examined during mandibular and sub-mandibular mechanical stimulations in healthy subjects during …

Cortical Statistical Correlation Tomography Of Eeg Resting State Networks, Chuang Li, Han Yuan, Guofa Shou, Yoon-Hee Cha, Sridhar Sunderam, Walter Besio, Lei Ding

Biomedical Engineering Faculty Publications

Resting state networks (RSNs) have been found in human brains during awake resting states. RSNs are composed of spatially distributed regions in which spontaneous activity fluctuations are temporally and dynamically correlated. A new computational framework for reconstructing RSNs with human EEG data has been developed in the present study. The proposed framework utilizes independent component analysis (ICA) on short-time Fourier transformed inverse source maps imaged from EEG data and statistical correlation analysis to generate cortical tomography of electrophysiological RSNs. The proposed framework was evaluated on three sets of resting-state EEG data obtained in the comparison of two conditions: (1) healthy …

In-Vitro Simulation Of Acute Ischemic Stroke, Paolo Garcia

Biomedical Engineering Undergraduate Honors Theses

Acute ischemic stroke (AIS) is a condition that involves the occlusion of a blood vessel within the brain, effectively preventing the passage of oxygen and nutrients. AIS is highly prevalent in the United States, where nearly 795,000 strokes happen per year and 87% of those are ischemic. From a medical standpoint, the obstructing clot can be removed with the use of a stroke retrieval device. However, a need arises for testing the aforementioned devices on a patient’s specific vascular geometries in order to increase the likelihood of a successful procedure. Outlined is a process for developing a physical simulation of …

Comparison Of Varying Tissue Freezing Methods On Murine Colonic Tissue, James Hughes

Biomedical Engineering Undergraduate Honors Theses

Histology often requires a tissue specimen to be embedded so that it may be sectioned, stained, and mounted on a microscope slide for viewing. One common method of tissue embedding for rapid histology is freezing, since freezing allows tissue to be stored without the need for fixing. Frozen tissue is often embedded in a medium such as Optimal Cutting Temperature (OCT) compound so that it can be sectioned using a cryostat. However, factors such as ice-crystal formation during the freezing process can cause damage to the tissue. As such, the protocol used to freeze the tissue can affect the quality …

Neural Mechanisms Of Transcranial Magnetic Stimulation In The Treatment Of Tinnitus, Andrea S. Lowe

USF Tampa Graduate Theses and Dissertations

Millions of people suffer from tinnitus, a disorder for which there is currently no effective treatment or cure. My dissertation work provides insight into the neural correlates of this pervasive hearing disorder and examines how a newly emerging therapy, transcranial magnetic stimulation (TMS), affects the central auditory system in the generation of the tinnitus percept. This work has a multifold focus of: i) developing and modeling the function of a miniature magnetic coil that can be used for TMS in rodents, ii) establishing a reliable mouse model of tinnitus that can be used for assessing TMS treatment-induced changes, iii) measuring …

Optimization Of Wavelength Selection For Multispectral Image Acquisition: A Case Study Of Atrial Ablation Lesions, Huda Asfour, S. Guan, Narine Muselimyan, Luther M. Swift, Murray Loew, Narine Sarvazyan

Pharmacology and Physiology Faculty Publications

In vivo autofluorescence hyperspectral imaging of moving objects can be challenging due to motion artifacts and to the limited amount of acquired photons. To address both limitations, we selectively reduced the number of spectral bands while maintaining accurate target identification. Several downsampling approaches were applied to data obtained from the atrial tissue of adult pigs with sites of radiofrequency ablation lesions. Standard image qualifiers such as the mean square error, the peak signal-to-noise ratio, the structural similarity index map, and an accuracy index of lesion component images were used to quantify the effects of spectral binning, an increased spectral distance …

Quantum Confined Peptide Assemblies With Tunable Visible To Near-Infrared Spectral Range, Kai Tao, Zhen Fan, Leming Sun, Pandeeswar Makam, Zhen Tian, Mark Ruegsegger, Shira Shaham-Niv, Derek Hansford, Ruth Aizen, Zui Pan, Scott Galster, Jianjie Ma, Fan Yuan, Mingsu Si, Songnan Qu, Mingjun Zhang, Ehud Gazit, Junbai Li

Faculty & Staff Scholarship

Quantum confined materials have been extensively studied for photoluminescent applica- tions. Due to intrinsic limitations of low biocompatibility and challenging modulation, the utilization of conventional inorganic quantum confined photoluminescent materials in bio- imaging and bio-machine interface faces critical restrictions. Here, we present aromatic cyclo-dipeptides that dimerize into quantum dots, which serve as building blocks to further self-assemble into quantum confined supramolecular structures with diverse morphologies and photoluminescence properties. Especially, the emission can be tuned from the visible region to the near-infrared region (420 nm to 820 nm) by modulating the self-assembly process. Moreover, no obvious cytotoxic effect is observed for …

Development Of Low Frequency Electron Paramagnetic Resonance Methods And Instrumentation For Biological Applications, Laura A. Buchanan

Electronic Theses and Dissertations

EPR is a powerful biophysical tool that can be used to measure tumor physiology. With the addition of magnetic field gradients, the spectral properties of paramagnetic species can be mapped. To facilitate EPR imaging, methods and instrumentation at frequencies between 250 MHz and 1 GHz were developed.

At low spin concentrations, the rapid scan background signal is often many times larger than the EPR signal of interest. To help remove the background contribution, a data acquisition procedure that takes advantage of a cross-loop resonator and bipolar power supplies was developed at 250 MHz. In this procedure, two scans are collected. …

Tumor Cell Death After Electrotransfer Of Plasmid Dna Is Associated With Cytosolic Dna Sensor Upregulation, Katarina Znidar, Masa Bosnjak, Nina Semenova, Olga N. Pakhomova, Loree Heller, Maja Cemazar

Bioelectrics Publications

Cytosolic DNA sensors are a subgroup of pattern recognition receptors (PRRs) and are activated by the abnormal presence of the DNA in the cytosol. Their activation leads to the upregulation of pro-inflammatory cytokines and chemokines and can also induce cell death. The presence of cytosolic DNA sensors and inflammatory cytokines in TS/A murine mammary adenocarcinoma and WEHI 164 fibrosarcoma cells was demonstrated using real time reverse transcription polymerase chain reaction (RT-PCR), western blotting and enzyme-linked immunosorbent assay (ELISA). After electrotransfer of plasmid DNA (pDNA) using two pulse protocols, the upregulation of DNA-depended activator of interferon regulatory factor or Z-DNA binding …

Targeting Ovarian Cancer And Endothelium With An Allosteric Ptp4a3 Phosphatase Inhibitor, Kelley E. Mcqueeney, Joseph M. Salamoun, James C. Burnett, Nektarios Barabutis, Paula Pekic, Sophie L. Lewandowski, Danielle C. Llaneza, Robert Cornelison, Yunpeng Bai, Zhong-Yin Zhang, John D. Catravas

Bioelectrics Publications

Overexpression of protein tyrosine phosphatase PTP4A oncoproteins is common in many human cancers and is associated with poor patient prognosis and survival. We observed elevated levels of PTP4A3 phosphatase in 79% of human ovarian tumor samples, with significant overexpression in tumor endothelium and pericytes. Furthermore, PTP4A phosphatases appear to regulate several key malignant processes, such as invasion, migration, and angiogenesis, suggesting a pivotal regulatory role in cancer and endothelial signaling pathways. While phosphatases are attractive therapeutic targets, they have been poorly investigated because of a lack of potent and selective chemical probes. In this study, we disclose that a potent, …

Nano-Pulse Stimulation Ablates Orthotopic Rat Hepatocellular Carcinoma And Induces Innate And Adaptive Memory Immune Mechanisms That Prevent Recurrence, Brittany P. Lassiter, Siqi Guo, Stephen J. Beebe

Bioelectrics Publications

Nano-pulse stimulation (NPS), previously called nsPEFs, induced a vaccine-like effect after ablation of orthotopic N1-S1 hepatocellular carcinoma (HCC), protecting rats from subsequent challenges with N1-S1 cells. To determine immunity, immune cell phenotypes were analyzed in naïve, treated and protected rats. NPS provides a positive, post-ablation immuno-therapeutic outcome by alleviating immunosuppressive T regulatory cells (Treg) in the tumor microenvironment (TME), allowing dendritic cell influx and inducing dynamic changes in natural killer cells (NKs), NKT-cells and T-lymphocytes in blood, spleen and liver. NPS induced specific increases in NKs and NKT-cells expressing CD8 and activation receptors CD314-NKG2D and CD161 (NK1.1) in the TME …

The Effects Of Emerging Technology On Healthcare And The Difficulties Of Integration, Skyler J. Pavlish-Carpenter

Honors Undergraduate Theses

Background: Disruptive technology describes technology that is significantly more advanced than previous iterations, such as: 3D printing, genetic manipulation, stem cell research, innovative surgical procedures, and computer-based charting software. These technologies often require extensive overhauls to implement into older systems and must overcome many difficult financial and societal complications before they can be widely used. In a field like healthcare that makes frequent advancements, these difficulties can mean that the technology will not be utilized to its full potential or implemented at all.

Objective: To determine the inhibiting factors that prevent disruptive technology from being implemented in conventional healthcare.

Methods: …

Characterization Of Language Cortex Activity During Speech Production And Perception, Hassan Baker

Electrical & Computer Engineering Theses & Dissertations

Millions of people around the world suffer from severe neuromuscular disorders such as spinal cord injury, cerebral palsy, amyotrophic lateral sclerosis (ALS), and others. Many of these individuals cannot perform daily tasks without assistance and depend on caregivers, which adversely impacts their quality of life. A Brain-Computer Interface (BCI) is technology that aims to give these people the ability to interact with their environment and communicate with the outside world. Many recent studies have attempted to decode spoken and imagined speech directly from brain signals toward the development of a natural-speech BCI. However, the current progress has not reached practical …