Engineering Commons^™

Design And Assembly Of A Lightweight, Multi-Cannula Tetrode Drive For Bilateral Hippocampal And Acc Recordings, Homero Phelps, Jasmine Sidhu, Jonathan V. Trinidad, Talha Soluoku

Undergraduate Research Symposium Posters

Implants and Electrophysiology:

Electrophysiology is the study of the electrical properties of cells and tissues, neuronal implants enable high-resolution recordings of neuron action potentials and their locations in the brain.

Data gathered is key in investigating/mapping cognition and effects of neurological pathologies on regular neural systems.

Hyperdrive Model:

Previous model was restricted to two implant sites, and displayed frequent tetrode deformation

Hyperdrive was modified to support four implant sites and 16 independently movable tetrodes using 3D modeling software, while keeping its weight below 1.5 grams.

Targets:

Researchers targeted the hippocampus (CA1, CA3) and ACC, using the novel bilateral model

Intercellular Stress Generation During 1d Collective Migration Of Cancer Cells, Logan Waddle

Physics Undergraduate Honors Theses

Physical forces drive many cellular processes such as migration and proliferation. A metastatic tumor will have invasive strands/chains that extend from the main tumor. These chains of cells collectively migrate away from the main tumor to establish new colonies elsewhere in the body. However, how physical forces drive this collective invasion and the required energy for this process is not well understood. Invasion of a metastatic tumor to surrounding tissues leads to a majority of cancer-associated death and is often a collective effort among cells, it is therefore important to fully understand the process behind collective cancer invasion.

The goal …

Analysis Of The Mechanical, Microstructural, And Biocompatibility Properties Of Novel Magnesium-Based Hybrid Nanocomposite Materials For Orthopedic Applications, Thomas H. Mcgehee

Biomedical Engineering Undergraduate Honors Theses

Bone fractures and complete joint replacements are becoming more common, primarily because of accidents and age-related issues. Conventional solutions to treat these orthopedic injuries involve inert metal alloys to correct bone fractures until the healing process is complete, where a secondary revision surgery is then required to remove the implant. Issues regularly associated with these solutions include stress shielding, bone resorption, infection, inflammation, and implant loosening. Magnesium (Mg)-based nanocomposites offer promising potential as an alternative to commonly used metal alloys because of their favorable mechanical properties and biocompatibility. A particularly advantageous property of Mg is its natural biodegradation in vivo, …

Gene Mutation And Chemotherapy Response In Azoxymethane Induced Colorectal Tumors, Maya M. Vance

Biomedical Engineering Undergraduate Honors Theses

Colorectal cancer research is a field of increasing importance as disease prevalence continues to increase over time. In looking at the origin of the disease, a driver gene known as p53 is of particular interest for its role in the stimulation of the mutated Wnt pathway. Developing as a missense-type mutation, this gene that ordinarily functions as a tumor suppressor is investigated as a gene of interest for tumor development. In this study, a mouse model was used to examine the development of colorectal cancer with a total of n=34 samples, including n=9 tumors and n=25 colons. The concentration of …

3d Bioprinting Of Hydrogel Scaffold Skin Equivalents For Cosmetic And Drug Testing, Allison Reno

All Dissertations

Tissue engineering scaffolds are a crucial element of generating larger 3D tissue equivalents for modeling and clinical grafting. Currently, much of scaffold technology has not been significantly updated since the introduction of manually pipetted hydrogels and electrospun fiber scaffolds. Both of these approaches have their advantages and disadvantages, but neither utilize emerging biofabrication techniques such as advanced 3D bioprinting and plotting. In addition to more precision in the outer geometries of the scaffold, the use of bioprinting also introduces the ability to shape hydrogels into very intricate porous inner patterns within the outer geometries. This allows for the design of …

Personalized Model Of Cardiac Fibroblast Signaling Using Patient-Specific Data, Elizabeth A. Schuler

Chemical Engineering Undergraduate Honors Theses

Heart disease is the leading cause of death worldwide for both men and women, and cardiac fibroblasts are critical to heart form and function. Essential roles of cardiac fibroblasts include cell-cell communication, cell-cell signaling, and synthesizing and degrading the extracellular matrix (ECM), which controls structural support and tissue repair of the heart. Abnormal fibroblast signaling can lead to negative impacts, including fibrosis, impaired heart function, and inflammation. A computational model of cardiac fibroblast signaling on Netflux and MATLAB software was adapted and utilized to determine the effect of patient-specific levels of cytokines, hormones, growth factors, peptides, and membrane tension on …

Identifying Novel Molecular Targets To Induce Ferroptosis In Drug-Tolerant Cancer Cells Through Computational Modeling, Haris J. Rana

Biological Sciences Undergraduate Honors Theses

Ferroptosis is an iron-dependent, reactive oxygen species (ROS)-driven form of regulated cell death in which the cell membrane is degraded by lipid peroxidation. It is regulated by multiple enzymes, such as glutathione peroxidase 4 (GPX4), which prevents membrane degradation by reducing lipid peroxides and protecting cells from oxidative damage. When inhibitors like RSL3 target GPX4, lipid peroxides build up, and toxic ROS compromises membrane integrity. Traditional anticancer treatments, such as most chemotherapies, aim to eliminate tumor cells by damaging DNA and triggering apoptosis. However, resistance to apoptosis is a “hallmark of cancer,” often resulting in treatment failure. As a distinct …

Tumor-Specific Surface Marker–Independent Targeting Of Tumors Through Nanotechnology And Bioorthogonal Glycochemistry, Hyesun Hyun, Bo Sun, Mostafa Yazdimamaghani, Albert Wielgus, Yue Wang, Stephanie Ann Montgomery, Tian Zhang, Jianjun Cheng, Jonathan S. Serody, Andrew Z. Wang

Chemical and Biochemical Engineering Faculty Research & Creative Works

Biological targeting is crucial for effective cancer treatment with reduced toxicity but is limited by the availability of tumor surface markers. To overcome this, we developed a nanoparticle-based (NP-based), tumor-specific surface marker–independent (TRACER) targeting approach. Utilizing the unique biodistribution properties of NPs, we encapsulated Ac4ManNAz (Maz) to selectively label tumors with azide-reactive groups. Surprisingly, while NP-delivered Maz was cleared by the liver, it did not label macrophages, potentially reducing off-target effects. To exploit this tumor-specific labeling, we functionalized anti–4-1BB Abs with dibenzo cyclooctyne to target azide-labeled tumor cells and activate the immune response. In syngeneic B16F10 melanoma and orthotopic 4T1 …

Examining The Effects Of Quercetin On Phenotypic Characteristics Of Human Mesenchymal Stem Cells, Thomas M. Needy

Biomedical Engineering Undergraduate Honors Theses

Introduction A significant obstacle to mesenchymal stem cell (MSC) potency and therapeutic utility is in vitro senescence, an irreversible cessation of replication associated with age-related complications. Senolytic drugs, such as quercetin, may be helpful in selectively culling senescent cells while leaving non-senescent cells unaffected, thereby increasing potency of high-passage MSCs.

Methods The phenotypic, genotypic, and immunomodulatory effects of quercetin were assessed using in vitro models. Senescent cells, created through repeated subculturing of MSCs in vitro, and non-senescent cells were treated with 10 μM quercetin, differentiated into osteocytes, adipocytes, and chondrocytes, and analyzed to observe the effect of quercetin.

Results Quercetin …

Using Deep Learning And Two-Photon Excitation Fluorescence Microscopy To Predict Breast Cancer Recurrence And Response To Chemotherapy, Nicholas Powell

Graduate Theses and Dissertations

Accurate prediction of breast cancer recurrence plays a critical role in guiding treatment decisions, particularly regarding the use of systemic therapy for patients. While genomic assays such as the Oncotype DX Recurrence Score offer valuable prognostic information, they are limited in accessibility and application. The work presented in this thesis explores an imaging-based approach for the prediction of breast cancer recurrence that combines multiphoton microscopy (MPM) with deep learning to classify individual breast cancer biopsy samples by risk of recurrence. Genomic differences in tumors with different recurrence potentials may translate to distinct optical and structural information that can be captured …

Insert Creation To Mimic Blood Vessels In Gel Phantoms, Courtney Bloom

Biomedical Engineering Undergraduate Honors Theses

Gel phantoms are commonly used in research settings due to their ability to mimic soft tissue. Creating these phantoms usually involves 3D printing an insert, embedding it in gel, and then washing the insert out. Polyvinyl alcohol (PVA) is typically used as the insert material, but it often swells and deforms the gel during the washout process. Aquapour, a water-soluble material, was investigated as a potential replacement for PVA. Unlike PVA, Aquapour comes in a powdered form that can be mixed with water to create a castable slurry. To create molds to cast Aquapour, SolidWorks was used to design two …

Fabrication And In Vitro Biocompatibility Assessment Of Composite-Coated Magnesium Materials, Bryce Williams

Biomedical Engineering Undergraduate Honors Theses

This study provides a comparative assessment of the corrosion, morphology, and biological properties of four of the most promising coating methods for magnesium in biomedical applications, namely micro-arc oxidation (MAO), graphene oxide (GO)-containing MAO coating, MAO/sol-gel composite coating, and MAO/polycaprolactone (PCL) polymer dip coating approaches. Despite the abundance of research focused on these promising approaches, there is a notable lack of comparative studies evaluating their properties. To this end, the investigated composite coatings are ZK60+MAO, ZK60+MAO/GO, ZK60+MAO/Sol-gel, and ZK60+MAO/PCL composite coating. Several tests were used to assess various properties of the prepared groups such as in vitro corrosion characteristics, surface …

Optimizing The Effects Of Yoda1 And Assessing The Effects Of Mrna Silencing Of Piezo1 Gene In Mesenchymal Stem Cells, Addison R. Mclaughlin

Biomedical Engineering Undergraduate Honors Theses

Mesenchymal stem cells (MSCs) are multipotent adult stem cells that are capable of differentiating into various skeletal tissues, making them promising candidates for regenerative medicine. A critical factor influencing their differentiation potential is mechanosensitivity, the ability to respond to mechanical stimuli. The mechanosensitive calcium ion channel PIEZO1 has emerged as a key regulator in this process, particularly in osteogenic differentiation. This study investigated the role of PIEZO1 in MSC osteogenesis through pharmacological activation using YODA1 and gene silencing via siRNA. Human bone marrow-derived MSCs were cultured and induced for osteogenic differentiation under varying concentrations and durations of YODA1 treatment. Alizarin …

Efficacy Of Mitophagy Inhibition As A Potentiating Agent For Conventional Chemotherapy, Morghan Relich, Shelby Bess

Biomedical Engineering Undergraduate Honors Theses

Cancer is a result of uncontrolled growth and reproduction of cells. Damaged or abnormal cells grow and multiply when they should not and in turn the cells continue to proliferate and metastasize. Malignant cells rely on functional mitochondria for proliferation, metastasis, and survival. These mitochondria maintain a functional mitochondrial network through a quality control mechanism called mitophagy. Mitophagy is a conserved intracellular process to maintain quality control and remove damaged mitochondria.

Previous research has been done to examine the effects of mitophagy in tumor cells, as well as the effects of mitophagy inhibition. One focus of current research has been …

Metabolic Responses Of Adipose-Derived Stem Cells In Collagen I Hydrogels, Caroline R. King

Biological Sciences Undergraduate Honors Theses

Peripheral nerve injury affects approximately 44 in 1 million people in the United States every year and can lead to incomplete nerve recovery and loss of motor and sensory function. A significant amount of energy is required for nerve injury repair. A lack of energy allocation to the injury site hinders repair. Current treatments include hollow nerve guidance conduits, decellularized nerve grafts, and autografts. However, they are limited by factors such as donor site morbidity and sustained immunosuppressive treatments. Using three-dimensional collagen I hydrogels laden with adipose-derived stem cells (ASCs) can assist in neural regeneration. Three-dimensional collagen scaffolds aim to …

In Vitro Investigation Of Macrophage Functional And Metabolic Modulation, Shelby Nicole Bess

Graduate Theses and Dissertations

Macrophages are a subset of immune cells with a variety of functions that are abundant in numerous tumor types such as colorectal and breast cancer. It has been suggested that macrophages may serve an important function as immune mediators in tumor behavior; however, macrophage activity is complex and remains not completely understood. The overall goal of this dissertation was to explore and exploit tumor-associated macrophage phagocytic function and the changes in their interactions with cancer cells in an in vitro mouse model and in 2D and 3D in vitro culture models. First, we wanted to better understand macrophage behavior under …

The Effect Of A Peptide Targeting Ligand On Transfection Efficiency Of Polymeric Nanoparticles To Dendritic Cells, Anthony Radka

Honors Theses

Autoimmune diseases affect approximately 5-8% of the global population, leading to chronic symptoms, long-term treatment, and reduced quality of life. Current therapies primarily rely on lifelong administration of immunosuppressants, which are associated with severe side effects and heightened susceptibility to infections. This has spurred interest in cellular therapies that manipulate dendritic cells (DCs) effectively and can selectively treat these diseases. This work aims to improve the efficacy of dendritic cell-based therapies using cationic polymers that can electrostatically complex with nucleic acids, forming nanoparticles referred to as polyplexes, that can deliver therapeutic nucleic acid cargo. These particles are a favorable alternative …

Deciphering And Translating Bioinspired Structures For Engineering Materials Design Via Computational Modeling And Machine Learning, Zhangke Yang

All Dissertations

Nature has evolved extraordinary structural materials—such as nacre, bone, and the mantis shrimp’s dactyl club—that achieve remarkable combinations of strength, toughness, and impact resistance. These properties arise from sophisticated synergies between structure and composition. Inspired by these biological systems, this dissertation presents a comprehensive investigation into bioinspired materials, uncovering fundamental mechanisms and providing guidance on designing materials with superior mechanical properties.

This dissertation begins by examining the "brick-and-mortar" structure of nacre, which informs the design of layered polymer-graphene nanocomposite films. Using coarse-grained molecular dynamics simulations, I elucidate mechanisms of dynamic wave propagation and energy dissipation in these systems, providing critical …

Understanding Dimensional Stability Of Polymer Surgical Mesh, Simeon J. Mckelvey

All Dissertations

Polymer surgical mesh is a biomedical implant that has revolutionized the repair of the abdominal wall and pelvic floor. Each year, over 1.6 million Americans undergo surgical procedures using polymer surgical mesh to treat conditions where internal organs protrude through weakened tissues. This material is used in approximately 90% of hernia repairs, 80% of stress urinary incontinence procedures, and 30% of pelvic organ prolapse surgeries.

Despite this widespread use of polymer surgical mesh, post-implantation complications have prompted regulatory investigation and scrutiny. These complications stem from the mesh's behavior within the human body, including wrinkling, contraction, and loss of fixation, which …

Deep Learning In Lung Cancer Pre- And Post-Radiation Therapy: Diagnosis Of Malignancy And Radiation-Induced Lung Injury From 3d X-Ray Ct., Benjamin Peter Veasey

Electronic Theses and Dissertations

Lung cancer remains the leading cause of cancer-related mortality worldwide, with early detection and accurate diagnosis being critical for improving patient outcomes. Additionally, the progression of Radiation-Induced Lung Injury (RILI) following Stereotactic Body Radiation Therapy (SBRT) for lung cancer presents a significant diagnostic challenge. This dissertation addresses these challenges by developing deep learning-based diagnostic tools for both pre-treatment lung nodule malignancy classification and post-treatment RILI identification using 3D X-ray CT imaging. The research is divided into two primary objectives. First, for lung nodule malignancy classification, we developed a biopsy-confirmed dataset, called NLSTx, to train and evaluate deep learning models while …

Design And Evaluation Of Antibody-Conjugated Microneedle Patch For Early Mrsa Biomarker Detection, Kylee Marie Pop, Alexis Richie, Nicholas Jenkins, Andrew Holmes

Honors Theses

Post-operative orthopedic surgical site infections (SSIs), specifically those caused by methicillin resistant Staphylococcus aureus (MRSA), present a significant clinical challenge due to delayed detection, increased morbidity, and current rising healthcare costs. Early detection of infection remains limited due to the current methods of diagnosis, which consist of observation of the surgical site and laboratory infrastructure for conformation of infection. To combat these issues, my team and I have designed and evaluated a minimally invasive microneedle diagnostic patch that continuously monitors for the presence of MRSA-associated biomarker PBP2a in interstitial fluids around surgical site incisions. Upon antigen detection, a colorimetric response …

Involvement Of Long Non-Coding Rna (Lncrna) Malat1 In Shear Stress Regulated Adipocyte Differentiation, Justin Caron, Marjan Ghanbariabdolmaleki, Madison Marino, Chong Qiu, Bo Wang, Michael Mak, Shue Wang

Biomedical Engineering Faculty Research and Publications

Adipocyte differentiation plays an important role in bone remodeling due to secretory factors that can directly modulate osteoblast and osteoclast, thus affecting overall bone mass and skeletal integrity. Excessive adipocyte differentiation within the bone marrow microenvironment can lead to decreased bone mass, eventually causing osteoporosis. The mechanical microenvironment of bone marrow, including fluid shear, maintains the balance of adipocyte and osteoblast differentiation during bone remodeling. However, how mechanical cues interact with long noncoding RNA (lncRNA) and regulate adipocyte differentiation remains unexplored. In this study, we investigated the mechanosensitive role of lncRNA MALAT1 during mesenchymal stem cells (MSCs) adipocyte differentiation. By …

A Neuroimmune Circuit Mediates Chemo Brain Pathology, Daniel Ahmadi

McKelvey School of Engineering Graduate Student Theses & Dissertations

Chemotherapeutic agents, while effective in targeting malignant tumors, often reduce the patients’ quality of life by inducing fatigue, pain, and motivational deficits. These symptoms are collectively referred to as “chemo brain.” The mechanisms underlying these adverse effects, and specifically whether fatigue and motivational impairments share a common etiology, remain poorly understood. The neural–immune substrates of these symptoms remain obscure, in part because standard preclinical regimens either bypass key systemic signals or introduce local toxicity confounds. Here, I establish and validate a three‑day, low‑dose intravenous cisplatin protocol that avoids peritoneal inflammation and severe renal injury yet produces robust, reversible fatigue and …

Mechanistic Investigation Of Ring-Opening Polymerization Of Polycaprolactone Using Tin(Ii) Catalysts: Ligand Effects And Biomedical Applications, Eva-Larue M. Barber

Honors Scholar Theses

This research explores the mechanistic aspects of ring-opening polymerization (ROP) of ε-caprolactone (CL) to produce polycaprolactone (PCL), a biodegradable polymer widely used in biomedical applications. The study investigates how light exposure and catalyst concentration influence polymerization efficiency, using tin(II) 2-ethylhexanoate [Sn(Oct)₂] as the catalyst in a non-polar toluene solvent at 90 °C. Reactions were conducted under either ambient light or black light bulb (BLB) illumination, with monomer-to-catalyst ratios of 1:1 and 200:1.

Proton nuclear magnetic resonance (¹H NMR) spectroscopy was used to analyze conversion efficiency by tracking the disappearance of monomer signals and appearance of characteristic PCL peaks. Results revealed …

Synthesis And Characterization Of Composite Hydrogels For Tissue Engineering: An Investigation On Mechanical Properties And Biocompatibility, Ismael Lamas Jr.

Theses and Dissertations

This study investigates the fabrication and characterization of Polyvinyl Alcohol (PVA)/agar double-network (DN) hydrogels for biomedical applications, focusing on mechanical strength, biocompatibility, and tissue engineering potential. Techniques like swelling ratio analysis and Fourier-transform infrared spectroscopy (FTIR), alongside antibacterial and cytotoxicity assays, were employed to evaluate the hydrogels' properties. Results show that increasing agar content enhances mechanical and physical properties, with swelling ratios increasing by 300% when agar makes up 6% of the hydrogel, compared to 140% without agar. A positive correlation was observed between agar concentration and compressive and tensile moduli. Load-relaxation rates, essential for viscoelastic properties, also improved with …

Impact Of Shear Flow On Marine Biofilms Using Hyperspectral Imaging, Shantanu Mahesh Kore

All Theses

Various microbial communities in marine biofilms cause biofouling on submerged surfaces, posing challenges to marine industries. Despite their ecological and economic importance, biofilms' biomechanical and biochemical responses to hydrodynamic shear stress are insufficiently understood, particularly in dynamic flow conditions. To fill this gap, our study uses an innovative fiber-optic hyperspectral imaging (HSI) system and a supercontinuum laser source to examine marine biofilms' structure, composition, and detachment behavior at different shear stress levels.

To detect spectral and spatial heterogeneity in live biofilms without labeling, we created a custom imaging pipeline that captures reflectance spectra in the 600-850 nm range, targeting microbial …

Gene Editing Combined With Apap Diet-Mediated Selection In A Ldlr-/- Mouse Model Of Familial Hypercholesterolemia, Pramita Suresh

All Theses

Cell-based gene therapy has garnered significant interest in treating familial hypercholesterolemia (FH), an autosomal co-dominant disorder characterized by elevated low-density lipoprotein cholesterol (LDL-C) levels. However, achieving a therapeutic threshold level of engraftment of gene-modified cells is a significant hurdle. In FH, as in most liver diseases, the transplantation of healthy gene-modified hepatocytes does not result in a selective advantage for the healthy hepatocytes over native hepatocytes for clonal expansion in the liver. In FH, as in most liver diseases, the transplantation of healthy gene-modified hepatocytes does not provide a selective advantage for the healthy hepatocytes over native hepatocytes regarding clonal …

Development Of A Portable Electroencephalogram With Display, Seth D. Davis

Electronic Theses and Dissertations

In this experiment, the goal was to design, build, and test an Electroencephalogram (EEG) circuit that would then be paired with a touchscreen display as a portable unit for use in Schizophrenic research at East Tennessee State University at the Quillen College of Medicine. The requirements for this prototype denoted that the device had to be able to obtain a signal from two electrodes placed on the head of an individual with a third attached to the ankle as a ground, amplify and filter the signal, and display the results on a touchscreen display for recording and analyzing. The circuit …

Applying Residence Time Distribution Theory To Coronary Thermodilution Curves., Jacob Michael Miller

Electronic Theses and Dissertations

Cardiovascular diseases remain the leading cause of death worldwide and coronary microvascular dysfunction is one cardiovascular disease which is particularly challenging to diagnose and treat. Coronary thermodilution is a widely used, invasive procedure to evaluate microvascular function by generating physiological indices such as coronary flow reserve and the index of microvascular resistance. Although commonly cited as an indicator dilution method in the cardiovascular literature, current coronary thermodilution techniques lack rigorous application of the accompanying mathematical framework, thereby leaving potentially valuable diagnostic information unexploited. This study bridges that gap by demonstrating the equivalence between indicator-dilution theory and residence time distribution theory …

Biomechanical Assessment Of Fracture Risk In Young Children With Healthy Bone And Osteogenesis Imperfecta., Keyonna Mckinsey

Electronic Theses and Dissertations

Osteogenesis imperfecta (OI) is a group of genetic bone disorders that can range from a mild increase in fractures in one’s lifetime to perinatally lethal. Biomechanical assessment via finite element analysis (FEA) can be used to provide subject specific evaluation of fracture risk and thus aid in furthering understanding of likelihood of fracture due to loading associated with common daily activities. Thus, the purpose of this dissertation research was to characterize the risk of femur fracture in young children with OI compared to that of healthy children when exposed to loading associated with common activities, specifically gait. To accomplish this, …