Engineering Commons^™

Isolation Of Metallic Single-Walled Carbon Nanotubes For Electrically Conductive Tissue Engineering Scaffolds, Jakob Hockman

Biomedical Engineering Undergraduate Honors Theses

Metallic single-walled carbon nanotubes (m-SWNTs) were separated from pristine SWNTs using affinity chromatography for use in electrically conductive tissue engineering scaffolds. Approximately one third of SWNTs have metallic properties. Separations were achieved using a protocol modified from Liu & coworkers (2011) in order to improve the method for cell culture environments. Samples enriched in m-SWNTs were isolated and characterized. However, challenges still remain for the complete separation of m-SWNTs from their semiconducting counterpart (s-SWNTs) using this protocol. Approaches to improve separation and reduce the difficulties associated with processing the nanotubes were suggested. One of the ultimate destinations of these nanotubes …

Development And Analysis Of A Statics And Kinematics Demonstration As A Learning Tool In The Biomechanics Classroom, Bethany D. Knight

Biomedical Engineering Undergraduate Honors Theses

This study was done with the objective of determining if students in the biomedical engineering department at the University of Arkansas would gain better understanding of basic biomechanics principles through the implementation of in-class demonstrations. Biomechanics was chosen because it is the first class taken in sequence after the “Introduction to Biomedical Engineering” class. A pre-demonstration survey was administered to gauge how comfortable the students were with the topics on the syllabus. Two demonstrations were done in class and related homework was assigned. The post-semester survey was administered and collected to determine how effective the students felt the presentations to …

A 'Tissue Model' To Study The Barrier Effects Of Living Tissues On The Reactive Species Generated By Surface Air Discharge, Tongtong He, Dingxin Liu, Han Xu, Zhichao Liu, Dehui Xu, Dong Li, Qiosong Li, Mingzhe Rong, Michael G. Kong

Bioelectrics Publications

Gelatin gels are used as surrogates of human tissues to study their barrier effects on incoming reactive oxygen and nitrogen species (RONS) generated by surface air discharge. The penetration depth of nitrite into gelatin gel is measured in real time during plasma treatment, and the permeabilities of nitrite, nitrate, O₃ and H₂O₂ through gelatin gel films are quantified by measuring their concentrations in the water underneath such films after plasma treatment. It is found that the penetration speed of nitrite increases linearly with the mass fraction of water in the gelatin gels, and the permeabilities of …

Pentaerythritol Triacrylate-Co-Trimethylolpropane Nanocomposite Scaffolds As Osteogenic Components For Bone Tissue Engineering, Mollie Marie Smoak

Honors Capstones

No abstract provided.

Development Of An Inflammatory Joint Fluid Corrosion Assessment Method For Metallic Biomaterials, Kathleen Pieri

Renée Crown University Honors Thesis Projects - All

There is currently no systematic way to analyze the corrosion response of orthopedic alloys in contact with human joint fluid. The goal of this project was to design and test a small device that can successfully run electrochemical tests on retrieved inflamed joint fluids. Methods of fluid testing analysis were also explored. The a small electrochemical cell was created using polypropylene for the body and an electrode cartridge that could be disposed of after each test. In total the device could hold 4 mL of liquid. Testes were preformed using titanium, stainless steel, and CoCrMo alloys as the working electrodes …

Engineering Of Polyketide Biosynthetic Pathways For Bioactive Molecules, Siyuan Wang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study is focused on engineering of natural product biosynthetic pathways for efficient production of pharmaceutically important molecules or generation of new bioactive molecules for drug development.

Plant natural products are an important source of therapeutics, such as paclitaxel (anticancer) and artemisinin (anti-malarial). Production of plant natural products relies on conventional plant cultivation and solvent extraction, which is time-consuming and cost-ineffective. This work built a biosynthetic platform in Escherichia coli using seven biosynthetic genes from plants and bacteria, which were used to make valuable compounds such as the strong antioxidant resveratrol and anti-inflammatory agent curcuminoids. Through different combinations of these …

Validation Of A Confocal Light Sheet Microscope Using Push Broom Translation For Biomedical Applications, Joshua Hutcheson

Graduate Theses and Dissertations

There exists a need for research of optical methods capable of image cytometry suitable for point-of-care technology. To propose am optical approach with no moving parts for simplification of mechanical components for the further development of the technology to the poin-of-care, a linear sensor with push broom translation method. Push broom translation is a method of moving objects by the sensor for an extended field of view. A polydimethylsiloxane (PDMS) microfluidic chamber with a syringe pump was used to deliver objects by the sensor. The volumetric rate of the pump was correlated to the integration time of the sensor to …

Crizotinib And Ceritinib Induce Apoptosis And Necrosis In Primary Rat Hepatocytes With Distinct Capacity, Alec T. Salminen

Biomedical Engineering Undergraduate Honors Theses

Drug development makes up a major portion of biomedical engineering research interests. The FDA oversees the introduction, experimentation, and implementation of all drugs before market approval is granted. Even after market approval is granted, the FDA continues to monitor the safety of all drugs. Crizotinib and ceritinib are two anaplastic lymphoma kinase (ALK) inhibitors recently approved by the FDA. Both drugs are indicated for treatment of non-small cell lung cancers (NSCLC) with abnormal ALK gene, and they are approved with a companion diagnostic test that determines ALK abnormality. Clinical trial data suggest that crizotinib and ceritinib can cause liver injury, …

Exploring Biomarkers For Point Of Care Bladder Cancer Detection, Cassandra M. Walker

Biomedical Engineering Undergraduate Honors Theses

Bladder cancer is the 5th most common non-cutaneous human cancer in the United States. While effective methods of detecting bladder cancer are currently practiced, they are often expensive and invasive. There is a need for a noninvasive detection method that can be used in areas with few medical resources. Cell free DNA in urine is normally present only in very low concentrations. Abnormally high levels of cell free DNA in urine could be indicative of disease. This study tests the hypothesis that DNA present in urine can be used as a biomarker for bladder cancer before hematuria is seen in …

Optimized Protocol For Measuring 2-Nbdg Uptake As A Cellular Marker Of Glycolytic Demand, Drew Folgmann

Biomedical Engineering Undergraduate Honors Theses

2[N-(7-nitrobenz-2-oxa-1,2-diaxol-4-yl)amino]-2-deoxyglucose (2-NBDG) a fluorescently tagged analog of FDG is ideal for in vitro studies and imaging. 2-NBDG has been proven to be an adequate marker for glucose uptake in many different types of cells [1]. However, across the spectrum of 2-NBDG use a lack of consensus is observed for the following questions. What is the ideal time to fast cells to optimize cellular uptake of 2-NBDG? Also, what is the ideal concentration of 2-NBDG to be used when quantifying glucose uptake? Finally, what is the effect of serum on the uptake of 2-NBDG? To answer these questions and understand glucose …

Micellular Electrokinetic Chromatography For Studying Amyloid Beta Oligomer Membrane Affinity, Andrew Bryson

Biomedical Engineering Undergraduate Honors Theses

Amyloid Beta (Aβ) was the major focus of this study. It is a peptide that is present in the brain with a high tendency to self-aggregate. When this protein aggregates, it forms oligomers and protofibrils which in turn are deposited as senile plaques in the brain. The reason for the concern with these plaques is their association with the neurological disorder Alzheimer’s disease. It has been found that the most dangerous oligomers are formed in a portion of the plasma membrane known as lipid rafts. The purpose of this study was to understand how micelles affect the aggregation properties of …

Non-Directional Conjugation Of Fluorescent Antibodies To Gold Nanoparticles For Stem Cell Therapy, Kunal B. Shah

Biomedical Engineering Undergraduate Honors Theses

The objective of this study was to design citrate-coated gold nanoparticles conjugated with FITC-IgG, a fluorescent antibody, and to qualitatively and quantitatively measure the resulting fluorescent emission. Optical properties of the gold nanoparticles were measured at various stages to provide evidence of successful conjugation. The absorbance spectrum of the citrate gold nanoparticles was compared to that of the reaction mixture containing the gold nanoparticles and the FITC-IgG. A noticeable broadening of the absorption peak was observed at 519 nm indicating a surface modification of the gold nanoparticles. Fluorescence data was obtained with a fluorospectrometer and revealed a significant amount of …

Design Of A 3d-Printed Device For Diffuse Reflectance Spectroscopy Calibration As A Step Towards Clinical Translation, Nontapoth Vongkittiargorn

Biomedical Engineering Undergraduate Honors Theses

The diffusive reflectance and spectroscopic microendoscopy (DRSME) is a multimodal imaging system that harnesses its usefulness from different light sources. One of the modalities, diffuse reflectance spectroscopy (DRS), has been used in our lab to investigate optical properties of epithelial tissues using a broadband white light as the main source. Calibration of DRS is required as it can obtain the maximum intensity and convert it to absolute reflectance. Current manual-adjusted calibration can be lengthy and often lead to inconsistent results. Therefore, a new method of calibration is introduced where additive manufacturing (or 3D printing) technology is fully utilized.

The instrumentation …

Portable High Throughput Digital Microfluidics And On-Chip Bacteria Cultures, Yiyan Li

UNLV Theses, Dissertations, Professional Papers, and Capstones

An intelligent, portable, and high throughput digital microfluidic (DMF) system is developed. Chapter 1 introduces microfluidics and DMF systems. In Chapter 2, a low-cost and high resolution capacitive-to-digital converter integrated circuit is used for droplet position detection. A field-programmable gate array FPGA is used as the integrated logic hub of the system for highly reliable and efficient control of the circuit. In this chapter a fast-fabricating PCB (printed circuit board) substrate microfluidic system is proposed. Smaller actuation threshold voltages than those previously reported are obtained. Droplets (3 µL) are actuated using 200 V, 500 Hz DC pulses. Droplet positions can …

Municipal Composting And Organic Waste Diversion: The Case Of Fayetteville, Arkansas, Michael E. Hoppe

Biological and Agricultural Engineering Undergraduate Honors Theses

It is estimated that 40% of food is wasted in the United States; representing $165 billion in wasted resources. A vast majority of that wasted food is ultimately placed in landfills where it decomposes and releases harmful greenhouse gases (GHGs). In fact, food waste alone is responsible for 23% of annual methane emissions for the US. This has a huge impact on global climate change due to the potency of methane as a greenhouse gas. Currently only 5% of the food waste produced is recovered across the nation. Source reduction would be the best solution to reducing this food waste, …

Manipulating The K-Space For Reduction Of Respiratory Induced Motion Artifacts, Maida Ranjbar

Bioengineering Theses - Archive

Respiratory induced motion artifacts, particularly those occurring in the abdomen and lung, pose a hefty problem in current diagnostic MR imaging. Application of images plagued with such artifacts not only hinder diagnosis, but may result in the enforcement of undesirably large safety margins in radiation therapy due to un-captured tumor characteristics that are concealed by the artifact. While several methods such as gated scans, breath-hold scans, variation of the K-Space acquisition trajectory, and reducing the scan time via partial acquisition or parallel imaging have been proposed as a solution, a robust and yet simple to implement remedy still remains to …

Experimental Assessment Of Mouse Sociability Using An Automated Image Processing Approach, Frency Varghese, Jessica A. Burket, Andrew D. Benson, Stephen I. Deutsch, Christian W. Zemlin

Electrical & Computer Engineering Faculty Publications

Mouse is the preferred model organism for testing drugs designed to increase sociability. We present a method to quantify mouse sociability in which the test mouse is placed in a standardized apparatus and relevant behaviors are assessed in three different sessions (called session I, II, and III). The apparatus has three compartments (see Figure 1), the left and right compartments contain an inverted cup which can house a mouse (called “stimulus mouse”). In session I, the test mouse is placed in the cage and its mobility is characterized by the number of transitions made between compartments. In session II, a …

Automated Analysis Of Cancerous Histological Samples., Thomas Allen Tennill

Electronic Theses and Dissertations

The use of immunohistochemistry has become commonplace in the field of cancer diagnosis. A major limitation to the ability to use this tool effectively is the time consuming tasks required for the analysis of data due to the fact that it is largely done by hand. Additionally, because of this, there is an inherent level of subjectivity in the results obtained from this process that may depend on who it is conducting the analysis. Therefore, there exists a need for a method that is able to quantify results from immunohistochemical techniques in a way that it is both time-effective and …

Efficacy Of Subcutaneous Electrocardiogram Leads For Synchronous Timing And Aortic Root Cannulation For Chronic Counterpulsation Therapy., Stephen R. Carnahan

Electronic Theses and Dissertations

Background: Counterpulsation devices (CPD) require electrocardiogram (ECG) lead implantation for timing device filling and ejection with the native heart. Non- implantable leads limit the scope of CPD treatment to short-term therapy. Standard transvenous/epicardial ECG leads increase the invasiveness of therapy.

Methods: To overcome these limitations, subcutaneous ECG leads were tested in chronic (n=6) and acute (n=5) bovine models. ECG waveforms from clinical- grade epicardial (control) leads and subcutaneous (test) leads were simultaneously recorded resulting in 830 data epochs (30-s each) for a total of 44,614 heart beats. Device triggering using R-wave detection was calculated for each lead type and compared. …

Development Of A Novel Device For Ventricular Assist Device Outflow Graft Anastomosis., Young Choi

Electronic Theses and Dissertations

Purpose: Left ventricular assist device (LVAD) therapy can be live-saving for advanced heart failure patients. Conventional anastomosis (surgical connection) of LVAD outflow grafts to the aorta requires aortic clamping and hand-suturing. Aortic clamping increases the risk for neurological complications. Hand-suturing may be time-consuming and requires significant surgical dexterity. There is currently no commercially available device for sutureless anastomosis of large vascular grafts (diameter > 5mm). To overcome these limitations, a prototype LVAD outflow graft anastomosis device (GrAD) that facilitates sutureless anastomosis was developed and tested to demonstrate proof-of-concept and feasibility for (1) secured attachment withstanding physiological pressures, and (2) comparable attachment …

Investigation Of The Tailoring Steps In Pradimicin Biosynthesis, Kandy L. Napan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research focused on the investigation of the late steps in the biosynthetic pathway of the novel antifungal and antiviral pradimicins A-C. Pradimicins were first isolated from the soil bacterium Actinomadura hibisca. These bioactive molecules are assembled by a type II polyketide biosynthetic pathway. Although the biosynthetic gene cluster of pradimicin has been identified, the functions of the biosynthetic genes and how they work collaboratively to form the final structures of pradimicins remain unknown. This research aims to functionally characterize the enzymes involved in the late steps of the biosynthetic route.

The early biosynthetic steps of pradimicins have been …

Multiphoton Imaging Of Labeled Breast Cancer Cells To Quantify Intra And Extracellular Receptors, Sydney C. Wiggins

Biomedical Engineering Undergraduate Honors Theses

Every year 200,000 women in the United States are diagnosed with breast cancer. Of the cases diagnosed, 10% -15% are classified as triple negative breast cancer (TNBC) due to the absence of estrogen, progesterone, and HER-2/Neu receptors. This breast cancer sub-type is markedly more aggressive and twice as likely to develop in premenopausal women. TNBC is resistant to endocrine therapies and current targeted agents, making clinical need for the development of validated therapeutics for TNBC a pressing matter. To initiate drug development, the internalization of directly immunolabeled epidermal growth factor receptors (EGFR) in SK-BR-3 human breast adenocarcinoma cells was quantitated …

Immunomodulation Of Breast Cancer Cells For Whole Tumor Vaccination, Kristina G. Maxwell

Biomedical Engineering Undergraduate Honors Theses

Hematogenous metastasis causes 90% of breast cancer-related deaths.Current therapies include chemotherapy and irradiation following surgery. These therapies are very harmful to the human body and do not elicit an anti-tumor immune response. To create a novel therapeutic, an autologous vaccine increasing the immunogenicity of non immunogenic breast cancer cell lines has been proposed.

To create this vaccine, 4T1 mouse mammary breast cancer cells have been selected as the desired cell line to treat. They are non immunogenic and highly invasive. In order to increase their immunogenicity, first projected, was the addition of cytokines to 4T1 cells to increase the expression …

Local Delivery Of Ctla-4 Blockade Inhibits Growth Of Pancreatic Tumors, Jack Baltz

Biomedical Engineering Undergraduate Honors Theses

Immune checkpoint blockade has demonstrated great potential in activating antitumor immunity. Ipilimumab is a monoclonal antibody which targets cytotoxic T-lymphocyte antigen-4. CTLA-4 belongs to the CD28 class of receptors and is found on the surface of CD4⁺ and CD8⁺ T cells. CTLA-4 acts to suppress the immune system when bound to CD80 and CD86 receptors on antigen presenting cells. Ipilimumab, or anti-CTLA-4, has shown to be effective in significantly extending the survival of patients with metastatic melanoma. However, systemic delivery of Ipilimumab also induces significant side effects such as: colitis, dermatitis, uveitis, and hypophysitis. In order to minimize …

Intravital Microscopy Of Tumor Oxygenation And Glycolytic Demand, Jesse D. Ivers

Biomedical Engineering Undergraduate Honors Theses

There is growing concern about the over treatment of cancer because treatments are based primarily on tumor anatomy. In this study, we aim to begin the process of addressing that issue by developing an intravital technique for optically analyzing tumor biology. Two traits were identified as having significant importance in the aggression of a tumor, vascular oxygenation (SO2) and glycolytic demand. Dorsal skin flap window chambers were implanted and 4T1 and 67NR cancer cells were injected to provide a tumor model for the development of this intravital quantification technique. This study provides a detailed protocol from instrumentation setup to surgical …

Customization Of Titanate Nanofiber Bioscaffolds, Jared Hopkins

Biomedical Engineering Undergraduate Honors Theses

In the field of orthopedic devices implant loosening is a major issue resulting in the majority of device failures. These failures result in the need for costly secondary procedures. To reduce device loosening an improved method of tissue anchoring is required. A previously studied titanate nanofiber bioscaffold has been shown to be safely implantable and to contribute to the differentiation of mesenchymal stem cells to osteocytes. Through the customization of both physical and chemical characteristics this titanate nanofiber bioscaffold was fabricated as a potential means to enhance tissue anchoring for use with orthopedic devices. This customization was enabled by acoustic …

Effect Of Impact Angle On Astrocyte Gene Expression, Nicholas A. Chavis

Biomedical Engineering Undergraduate Honors Theses

Over one million people each year experience some form of traumatic brain injury. Every individual’s injury is different as impacts can affect different parts of the brain in various ways. This study was conducted to test the impact angles effect on astrocytes by measuring gene expression of TNF- alpha, an inflammation marker, and GFAP, a gene released in response to reactive astrocytes, following impacts from 0, 45, and 90 degrees. Results were recorded from Polymerase Chain Reaction via the delta delta Ct method and compared to the control group for to show under-regulation or up- regulation of the genes of …

Investigating The Mechanical Behaviors Of Organic/Inorganic Composite Bone Scaffolds, Parker Davidson

Biomedical Engineering Undergraduate Honors Theses

The regeneration of bone over a large area cannot occur without a structure for the bone cells to bind and divide. The use of an organic/inorganic composite bone scaffold appears to be a promising alternative to the current clinical standard of bone grafting. Bone grafting is very limited, in that the size and shape of the area are hard to replicate and the use of donor tissue can trigger an immunologic response resulting in rejection of the bone tissue. This study experimented with composite bone scaffolds which can be made to fit the shape of the area in which bone …

Design Of Exercise Equipment For Wheelchair Users: A Case Study In Accessibility Standards, Kate Craddock Rescsanszky

Honors Scholar Theses

Engineers must consider a number of aspects of every project they work on. Accessibility is one aspect that presents a unique challenge. Rather than being based on absolute material parameters, accessibility is based on how people interact with technology and their built environment. Since 1990, the Americans with Disabilities Act has been the predominant standard in accessibility because of its wide reach and legal mandate. In addition to the ADA, the ASTM and the Institute for Universal Design offer helpful guidelines for designing for accessibility. However, in addition to standards, guidelines, and recommendations, it is important to consult the intended …

Fabrication And Characterization Of An Extracellular Matrix Hydrogel For Aortic Valve Applications, Brady Culbreth

All Theses

With an estimated 5 million people suffering from valve disease in the United, valve disease is currently the leading cause of cardiovascular disease. Each year, between 80,000 and 85,000 aortic valve replacements are performed in order to treat the stenotic heart valves. Despite this being a worldwide epidemic, the current valve replacement options that are on the market have distinct limitations. Furthermore, a viable alternative does not exist for the patients that are not candidates for the current treatment methods. Our proposed solution to this epidemic is to create a highly viable injectable scaffold that would allow for the minimally …