Biomedical Engineering and Bioengineering Commons^™

Optimizing Genetic Manipulation Of Methanogens Through Faster Cloning Techniques, Merrisa Jennings

Biological and Agricultural Engineering Undergraduate Honors Theses

Methanogenesis is the biological production of methane. Only anaerobic archaea known as methanogens are capable of such a metabolic feat. They have strict living conditions and substrate sources which determine their rate of metabolism. This is of particular importance from a greenhouse gas reduction perspective or biogas capturing perspective. One of the best ways to optimize methanogen methane production is via genetic manipulation. The current procedures are timely though, therefore a faster cloning processes should be developed. The objective of this study was to optimize a premade genetic transformation kit known as the Gibson Kit. The Gibson Kit was supposed …

In-Cage Surface Wetting System For Cooling Poultry In Transport, Ryan Clark

Biological and Agricultural Engineering Undergraduate Honors Theses

Abstract

Poultry health and mortality rates are important considerations in poultry production, as companies can minimize product loss and appeal to a consumer base whose concern for animal welfare continues to grow. Although animal welfare is a consideration for the entire poultry production process, this project focuses on the live-haul phase of the process, specifically during transport from grow houses to processing facilities. During the summer months, broiler chickens being transported can suffer from heat stress that can lead to death. This project consists of the designing and testing of an in-cage surface wetting system to minimize heat stress incidents …

Effects Of Gsk101 Exposure On Astrocyte Mechanical Properties, Collagen Production, And Viability, Ethan Echols

Biomedical Engineering Undergraduate Honors Theses

Transient receptor potential vanilloid 4 (TRPV4) is a cation channel protein which is thought to facilitate extracellular matrix (ECM) modification and glial scar formation following traumatic brain injury (TBI). Activation of TRPV4 has been shown to correlate with an increase in intracellular Ca²⁺ concentration. TRPV4 is subject to both chemical and mechanical activation. This study involved chemical activation of TRPV4 in cultured mouse astrocytes using GSK101, the primary agonist of TRPV4, and subsequent evaluation of mechanical and chemical changes to the ECM. Prior to GSK101 exposure, the cells were seeded into Matrigel Matrix, a gelatinous protein mixture intended to …

The Effect Of Elastin Degradation On The Biomechanical Properties Of Porcine Aortic Tissue, Caleb Nissen

Biomedical Engineering Undergraduate Honors Theses

The rupture of abdominal aortic aneurysms (AAA) is currently the 13^th leading cause of death in the United States [1]. AAA is characterized, in part, by an increase in presence of proteolytic enzymes which degrade the structural proteins collagen and elastin [6]. The goal of this study was to examine the effect that elastin degradation has on the biomechanical properties of aortic tissue. For this experiment, porcine aortic tissue was cut in the circumferential and longitudinal directions. These specimens were exposed to an elastase solution for varying time-intervals and then underwent uniaxial tensile testing. Elastase-treated tissue tested in the …

Extraction And Analysis Of Vector Flow Imaging Data In A Pediatric Population, Bailey Stinnett

Biomedical Engineering Undergraduate Honors Theses

Vector flow imaging (VFI) is a new ultrasound technology that provides real time, angle-independent visualization of flow velocities in the heart and great vessels. Thus far, VFI has been used for superficial applications due to the limited penetration depth of available transducer probes; however, this depth in smaller pediatric patients enables adequate aortic views. In this project, VFI was used to study pediatric aortic stenosis (PAS)—a congenital heart defect that results in the narrowing of the aorta and/or aortic valve. The decision to refer PAS patients for surgical or catheter-based intervention is initially based on Doppler ultrasound. VFI is potentially …

Analysis Of Biological Response To Ecm Hydrogel Injection, Grady Dunlap

Biomedical Engineering Undergraduate Honors Theses

Abstract

Under normal circumstances, skeletal muscle possesses the capacity to regenerate and heal via inflammatory and myogenic pathways. In cases of severe tissue loss or certain diseases, this capacity is lost, often resulting in loss of tissue function. Extracellular matrix (ECM), the protein scaffold which houses cells in physiological tissue, has been shown to have structural and chemical properties which influence cell migration and phenotype. This results in ECM’s capacity to encourage a regenerative response when implanted into severely damaged skeletal muscle. Additional advantages are apparent when an ECM scaffold is digested into a hydrogel, namely less invasive implantation via …

Experimental And Model-Based Terahertz Imaging And Spectroscopy For Mice, Human, And Phantom Breast Cancer Tissues, Tyler Bowman

Graduate Theses and Dissertations

The goal of this work is to investigate terahertz technology for assessing the surgical margins of breast tumors through electromagnetic modeling and terahertz experiments. The measurements were conducted using a pulsed terahertz system that provides time and frequency domain signals. Three types of breast tissues were investigated in this work. The first was formalin-fixed, paraffin-embedded tissues from human infiltrating ductal and lobular carcinomas. The second was human tumors excised within 24-hours of lumpectomy or mastectomy surgeries. The third was xenograft and transgenic mice breast cancer tumors grown in a controlled laboratory environment to achieve more data for statistical analysis.

Experimental …

Mitochondrial Mrna Translation Is Required For Maintenance Of Oxidative Capacity, David Lee

Graduate Theses and Dissertations

Oxidative metabolism is required to produce adequate energy to sustain human life. A primary example of deteriorating oxidative capacity is seen in the cardiac musculature during chronic heart failure. This suggests that by improving oxidative potential, chronic heart disease could be mitigated and one approach to accomplish this may be through targeting the mt-mRNA translation system. Purpose: This investigation’s purpose was to characterize disruptions in mt-mRNA translation machinery in multiple forms of cardiomyopathy and to determine if mitochondrial mRNA translation initiation factor (mtIF2) is necessary to maintain oxidative capacity in cardiomyocytes. Methods Using a combination of animal and cell culture …

Structure And Property Of Polymers And Biopolymers From Molecular Dynamic Simulations, Xiaoquan Sun

Graduate Theses and Dissertations

Natural and synthetic polymers and biopolymers have been studied for a variety of applications in food emulsion, biopharmaceutical purification, tissue engineering, and biosensor. The structure and property of polymers and biopolymers are critically important to determine their functions. Molecular dynamics (MD) simulations have a unique advantage to explore the structure and property of polymers and biopolymers from the molecular level. In the dissertation, MD simulations were conducted to study the mechanisms of various biological and chemical processes controlled by polymers and biopolymers based on real-world experimental results.

Seven heptapeptides have been screened from a peptide library in our earlier study …

Characterization Of Bacteriorhodopsin And Halorhodopsin Reconstituted In Lipid Bilayer Membranes, Joel Domkam Kamwa

Graduate Theses and Dissertations

Motivated to produce electricity with photon activated ion pumps, the main purpose of this work was to characterize the photosynthetic membrane proteins bacteriorhodopsin (proton pump) and halorhodopsin (chloride pump). The proteins were re-suspended in lipid bilayers. For this work, an experimental set-up was built which included: chambers for lipid bilayer formation and characterization, lasers for ion pump activation, and an AxoPatch electrophysiology system for small photocurrent measurement. Lipid bilayer membranes were formed using mostly folding method: folding two monolayers together. The membranes were characterized by their resistance, capacitance, and generated photocurrent. Photocurrent was generated upon illumination of lipid-protein membranes with …

Effects Of Hydration And Mineralization On The Mechanical Behavior Of Collagen Fibrils, Marco Fielder

Graduate Theses and Dissertations

Bone is a composite biomaterial with a structural load-bearing function. Understanding the biomechanics of bone is important for characterizing factors such as age, trauma, or disease, and in the development of scaffolds for tissue engineering and bioinspired materials. At the nanoscale, bone is primarily composed of collagen protein, apatite crystals, and water. Though several studies have characterized nanoscale bone mechanics as the mineral content changes, the effect of water, mineral, and carbon nanotube (CNT) content and distribution in fibril gap and overlap regions is unexplored. This study used molecular dynamics to investigate the change in collagen fibril deformation mechanisms as …

Novel Methodology For Emboli Analog Production And In-Vitro Simulation Of Acute Ischemic Stroke, Anne Preut

Graduate Theses and Dissertations

Stroke is the leading cause of disability and a primary cause of mortality, resulting in an estimated $33 billion dollars spent on healthcare, rehabilitation and lost productivity in the United States each year. The most prevalent cause of stroke incidents are acute ischemic events, manifested as blood clots in the vasculature supplying the brain. Current gold standard treatments have improved since 2006 with the introduction of mechanical stent retrievers; however, several issues with the current treatments to acute ischemic stroke remain. Thrombolysis of the clot with a tissue plasminogen activator may lead to weakening the vessel wall and consequently, hemorrhaging. …

Computational Fluid Dynamics Model For Air Velocity Through A Poultry Transport Trailer In A Holding Shed, Christian Heymsfield

Graduate Theses and Dissertations

Broiler production in Arkansas was valued at over $3.6 billion in 2013 (University of Arkansas Division of Agriculture Cooperative Extension Service). Consequently, improvement in any phase of the production process can have significant economic impact and animal welfare implications. One area of concern for the poultry industry is thermal stress experienced by the birds after arrival at the processing plant and before they are taken in to be processed, during which time they are left to wait in holding sheds. Various cooling strategies exist to mitigate heat stress in holding sheds, but in most cases it is unlikely that they …

Effects Of Uniaxial Cyclic Strain On Endothelial Progenitor Cells, Maria Alejandra Zeballos Castro

Biomedical Engineering Undergraduate Honors Theses

Despite the high prevalence of calcific aortic valve disease (CAVD), the underlying mechanisms of pathogenesis have not been found yet. Therefore, it is extremely important to study CAVD and understand how it develops. For this matter, we decided to study the potential of endothelial progenitor cells (EPCs) for use in tissue-engineered models of heart valves. EPCs were chosen as the cell source of interest for this study due to their high neovascularization potential and use in regenerative medicine and cardiovascular tissue engineering.

In this project, we aimed to engineer the microenvironment of cells that are involved in the formation of …

Intravenous Administration Of Iron Oxide Nanoparticles In The Chicken Model, Huong Thi Ngoc Le

Graduate Theses and Dissertations

To be used in health care, the safety and effectiveness of nanoparticles needs to be tested in a living organism. The objective of this project was to develop the chicken as a convenient animal model to examine tissue targeting of intravenously (i.v.)-injected iron oxide (IO) nanoparticles. In Experiment 1, different doses of IO-COOH were i.v. injected into chickens; blood was collected at 0, 5, 15, 30, and 60 minutes post-injection; liver, spleen, lung, and kidney were collected after the last blood collection. For Experiment 2, IO-COOH and IO-PEG were i.v. injected into chickens; blood and the organs were collected at …

Evaluating Thermal Comfort Of Broiler Chickens During Transportation Using Heat Index And Simulated Electronic Chickens, Kaushik Luthra

Graduate Theses and Dissertations

Broilers experience high physiological stress during pre-slaughter transport, especially under extremes of thermal environment. Characterization of thermal environment on the trailer is crucial to identify stress-prone regions during transportation. At the same time, Broilers experience high physiological stress during pre-slaughter transport, especially under extremes of thermal environment. Characterization of thermal environment on the trailer is crucial to identify stress-prone regions during transportation. At the same time, quantification of heat loss of the broilers loaded on trailers is important in understanding the well-being of the broilers. We have developed four electronic chickens (E-chickens) to simulate the sensible heat loss of live …

Mushroom Inoculation On Switchgrass Feedstock During Storage: Effects Of Subsequent Pre-Processing For Intended Biofuels Production, Amandeep Singh Turay

Graduate Theses and Dissertations

The objective of this project was to examine the effect of fungal treatment and liquid hot water pretreatment of switchgrass combine in view of increasing glucose release. The fungal treatment consisted of incubating Pleurotus ostreatus in square switchgrass bales, at 50% moisture content for 25 days, 54 days, and 82 days. The digestibility of the switchgrass biomass was subsequently evaluated using Accelerase 1500 enzyme. Lignin is an important barrier to enzymatic hydrolysis, and it was stipulated that incubation with P. ostreatus would disrupt plant cell walls, resulting in enhanced saccharification. Three different concentrations of P. ostreatus were evaluated: 0%, 2%, …

Effects Of Filtration Conditions On Clearance Of Bacteriophage, Rigen Te

Graduate Theses and Dissertations

Virus Clearance is one of the major challenges in biopharmaceutical industry, especially in the manufacturing of drugs. U.S. Food and Drug Administration (FDA) recommends using several model bacteriophages as surrogates of pathogenic mammalian virus for process validation. In this work, two bacteriophages were tested against 30 kDa, 100 kDa, 300 kDa polyethersulfone (PES) membranes to investigate the effects of pore size on virus clearance. Virus particles were spiked into the protein feed solutions containing bovine serum albumin (BSA) or lysozyme at different concentrations. Besides protein concentration, the effects of feed pH on the filtration performance and virus rejection were also …

Blood-Brain Barrier-On-A-Chip Systems Based On 3d Printing, Cade I. Harding

Mechanical Engineering Undergraduate Honors Theses

This research focused on the design and testing of a blood-brain barrier (BBB)-on-a-chip microfluidic device produced using 3D printing. First, COMSOL simulations were used to define dimensions of the microchannel that would most accurately replicate the flow environment imposed on the blood-brain barrier, the wall shear stress being the most important characteristic. In using COMSOL, water was used as the simulated fluid and also the testing fluid in the fabricated devices. Therefore, the microsystem is designed to produce the BBB environment using water instead of blood. The numerical simulation parameters were based on theoretical calculations performed to scale up the …

Optical Imaging Of Metabolic Adaptability As A Biomarker For Metastatic Potential In Breast Cancer Cells, Mason G. Harper

Biomedical Engineering Undergraduate Honors Theses

Breast cancer metastasis is the main cause for mortality in breast cancer patients. However, knowledge of metastatic recurrence is limited, and there is a need to understand metastatic recurrence in order to treat breast cancer patients more effectively. Highly invasive metastatic breast cancer has shown to exhibit metabolic adaptability, transitioning from glycolysis to oxidative phosphorylation in the presence of microenvironmental stress. NADH and FAD are naturally occurring cofactor products during glycolysis and oxidative phosphorylation, respectively, and they are of particular importance during these metabolic processes due to their endogenous fluorescence. Measuring the ratio of fluorescence intensities of these cofactors through …

Age's Effect On Regenerative Capabilities Of Myocytes Through Satellite Cell Analysis, Karam S. Sra

Biomedical Engineering Undergraduate Honors Theses

The objective of this study was to investigate potential effects aging had on muscle fiber area and satellite cell count in myocytes. This research could help elucidate the detrimental effect age has on regenerative capabilities whether in terms of satellite cell function or satellite cell number. Satellite cells are primarily responsible for generating new muscle tissue after being activated through mechanotransduction of injury. This study utilized immunofluorescence to examine the presence of the PAX7 gene expression, a unique marker of satellite cells, within a 12 month and 18 month old population of mice. The PAX7 marker was co-stained with DAPI …

Detection Of Leukocytes Stained With Acridine Orange Using Unique Spectral Features Acquired From An Image-Based Spectrometer, Courtney J. Hunter

Biomedical Engineering Undergraduate Honors Theses

A leukocyte differential count can be used to diagnosis a myriad blood disorders, such as infections, allergies, and efficacy of disease treatments. In recent years, attention has been focused on developing point-of-care (POC) systems to provide this test in global health settings. Acridine orange (AO) is an amphipathic, vital dye that intercalates leukocyte nucleic acids and acidic vesicles. It has been utilized by POC systems to identify the three main leukocyte subtypes: granulocytes, monocytes, and lymphocytes. Subtypes of leukocytes can be characterized using a fluorescence microscope, where the AO has a 450 nm excitation wavelength and has two peak emission …

Characterization Of The Response Of Trpv4 To Chemical Stimulation, Jacob V. Schluns

Biomedical Engineering Undergraduate Honors Theses

Traumatic Brain Injury (TBI) is a source of acute and chronic health issues for many patients. One of the components of the brain’s response to injury is astrogliosis, in which astrocytes that normally function to repair the brain instead form scar tissue that halts repair processes. Transient Receptor Potential Vanilloid Type 4 (TRPV4) is a trans-membrane calcium channel involved in astrogliosis. Through Fura-2AM based calcium imaging, the base activity of this channel in mouse astrocyte cells was recorded. The cells were then subjected to TRPV4 agonist and antagonist stimulation and their subsequent activity levels were recorded. The data showed that …

Optimizing A Standard Fasting Time For 2-Nbdg Uptake Studies In Murine Breast Cancers, Andrew C. Briley

Biomedical Engineering Undergraduate Honors Theses

Recently, there has been a larger use of 2-NBDG, a fluorescent glucose analog, to study glucose uptake in different cell types. These cell types have ranged anywhere from bacteria to human cancer cells. However, there has yet to be a standard procedure and practice for using 2-NBDG. In this study, our goal is to create a standard fasting time for the cells before introducing 2-NBDG to them. This study uses 4T07 cells, a murine breast cancer cell line, to help optimize this fasting time. These cells were fasted at different time points in order to find the ideal fasting time. …

Effect Of Storage Temperature And Time On Lyophilized Water Bark Extract's Biological Activity, Jillian Schneider

Biological and Agricultural Engineering Undergraduate Honors Theses

Sweetgum bark extract has been known to show biological activities such as antimicrobial and antioxidant capabilities. The storage capacity of the extract, however, was unknown and previously thought to diminish over time. However, upon experimentation, the freeze-dried sweetgum bark extract showed no signs that storage time or storage temperature had any significant effect on the biological activities. There was no significant difference across storage temperature over time in the experiment (ANOVA RM, P0.05). Therefore, the antioxidant capabilities of the sweetgum extract were not affected by the storage time or temperature treatments studied in this work. For the antimicrobial experiment, there …

In Vivo Multi-Parametric Imaging Of Metastatic And Non-Metastatic Breast Cancer, Raisa B. Rasul

Biomedical Engineering Undergraduate Honors Theses

A current issue in cancer therapy is the characterization of metastatic tumors, which can increase ease of treatment and patient trials. We present an in vivo study of metastatic (4T1) and non-metastatic (4T1-TWIST KO) breast tumor sister cell lines to understand their metabolic behavior, determine differences in two modes of imaging (reflection & transmission), and observe effect of breathing higher oxygen percentage on vascular hemoglobin oxygen saturation. After injection of 10,000 cells into mice dorsal window chambers, the glucose intake and hemoglobin oxygen saturation was measured using a fluorescent glucose analog (2-NBDG) and hyperspectral trans-illumination imaging from 520-620 nm at …

Metabolic Response To Stress Differentiates Heterogeneous Cancer Cells With Varying Metastatic Potential, Kinan Alhallak

Biomedical Engineering Undergraduate Honors Theses

Intratumoral heterogeneity is ubiquitously present within primary tumors and contributes to intractable behaviors such as metastasis and mutability spatiotemporally. Mounting evidence has shown that heterogeneous cell populations can adversely affect cell metabolism and metastatic potential. The cell’s only fluorescent molecules within the electron transport chain, flavin adenine dinucleotide (FAD) and nicotinamide adenine dinucleotide (NADH), can allow the quantitation of cell metabolism. We demonstrate the use of the optical redox ratio (FAD/(NADH+FAD)) to determine the metabolic behaviors of a heterogeneous panel of cells with varying metastatic programs at normal conditions and following acute hypoxia. At normal conditions, we reveal an attenuation …

Role Of Trpv4 In Astrocyte Extracellular Matrix Production, Abby Terlouw

Biomedical Engineering Undergraduate Honors Theses

Traumatic Brain Injury (TBI) is an alteration of brain pathology following damage of the central nervous system (CNS) by an external force. In the CNS, glial scar formation often occurs following TBI, and astrocytes are widely believed to contribute to this scar formation. While the role of astrocytes in extracellular matrix (ECM) production is known, the exact mechanism(s) for this event remain unclear. One possible method is the activation of transient receptor potential vanilloid 4 (TRPV4). TRPV4 is a channel protein found in the astrocyte membrane which has been shown to generate intracellular calcium ions following mechanical stimulation. Previous research …

Characterization Of Murine Breast Cancer Cell Lines For Anti-Cancer Vaccine, Haven N. Frazier

Biological Sciences Undergraduate Honors Theses

Breast cancer is the most commonly diagnosed cancer in women and the second leading cause of cancer death among women in the United States (1). While treatments involving radiation and chemotherapy currently exist, disease must be detected early in order for the treatments to be somewhat effective, and there is no effective treatment after metastasis occurs (2). Additionally, current therapies do not mitigate tumor immunosuppression. Decreasing the tumor-associated immunosuppressive conditions while activating antitumor immunity could prevent recurrence and metastasis, possibly leading to an effective treatment for cancer (3). Tumor cell vaccines could possibly address this issue and have become a …

Sensitivity Of Diffuse Reflectance Spectroscopy To Dose- And Depth-Dependent Changes In Tumor Oxygenation After Radiation Therapy, Daria Semeniak

Graduate Theses and Dissertations

Along with chemotherapy, immunotherapy, and surgery, radiotherapy is one of the most common treatments used against cancer. Around 50% of all cancer patients undergo radiation therapy. While for some patients radiotherapy works efficiently and lead to a complete cancer disappearance, for others treatment outcome may be less favorable due to radioresistance processes happening within a tumor on the molecular level. Radioresistance remains a big challenge for modern oncology. The ability to identify radioresistance at the early stage of radiotherapy would help physicians to improve therapy efficiency. At the current moment, despite the rapid progress in cancer understanding and diagnostic modalities, …