Biomedical Engineering and Bioengineering Commons^™

Analyzing Diverse Student Experiences: The Intersection Of Equity, Inclusivity, And Biomedical Engineering Education Through A Clinical Observations And Needs Finding Course, Jacquelynn Horsey

Biomedical Engineering Undergraduate Honors Theses

In the field of biomedical engineering, needs identification and solution development are an important element of the design process. In our undergraduate curriculum, a course was designed to allow clinical observation and provide an opportunity for students to learn about engineering design and engage with clinicians via completing rotations in medical facilities near our campus. While this type of course is not unique, evaluating its efficacy is not simple. Given the broad range of institutional resources available- such as proximity to a medical school, or residency programs- reporting the quality of such courses within the context of such available resources …

The Determination Of Macrophage Localization In Muscle Injuries Using Spatial Transcriptomics, Julliana Renales

Biomedical Engineering Undergraduate Honors Theses

The repair of traumatic muscle injury is often a long process which can in many cases be insufficient and incomplete. In such cases, scar tissue may form, leading to high risk of re-injury and the prevention of muscle regeneration. An important part of decreasing this risk is gaining a better understanding of the cellular complexities of injury repair. More specifically, macrophage cells are an important piece in the regulation of inflammation and repair. In this project, computational analysis spatial transcriptomic data was performed to examine mouse muscle injury and its development over time. This analysis was used to examine the …

Investigation Of Early Stage Wound Healing In Volumetric Muscle Loss, Sean Ong

Biomedical Engineering Undergraduate Honors Theses

Volumetric muscle loss (VML) refers to the substantial removal of tissue from skeletal muscle due to surgery or lesions. This condition disrupts the normal regenerative process of injured muscles, leading to significant loss of muscle function. This study examines the progression of VML injury, approximately 20% of the muscle mass being removed, in the tibialis anterior (TA) muscle of a mouse model over a 15-day post-injury period. The injured muscles exhibited discoloration indicative of reduced blood flow and experienced a decrease in muscle mass throughout the study duration. Furthermore, the maximum force output of the injured TA was significantly lower, …

Biomass Derived Lignin Polymer Modification For Sustainable Chemical Engineering Applications, Samantha Glidewell, Keisha Walters

Chemical Engineering Undergraduate Honors Theses

Lignin is an abundant naturally occurring plant-based polymer that is branched, highly unsaturated, and rich in aliphatic and aromatic hydroxyl groups. Lignin is a significant byproduct of the wood pulp and paper industries; however, it has yet to be widely utilized in commercial applications due to its non-linear structure, broad range of molecular weights, hydrophobicity, high rigidity, and brittleness. Recent investigations into modifying lignin to broaden its potential uses have shown promising results. This thesis explores different modification techniques of the naturally occurring hardwood lignin polymer for specific applications in areas of water treatment and polyurethane (PU) production. The first …

Sports Science: An Entrepreneurial Venture, Nicole J. Jones

Senior Honors Projects

In sports science, ensuring maximum athlete safety and optimizing data utilization are pivotal yet leave room for further work. My project, Unbeaten SafeWare, addresses these critical issues by focusing on two primary concerns: preventing heat-related and cardiac illnesses, which are significant causes of athlete fatalities, and enhancing the transparency and utility of sports data. This initiative involves developing a shirt integrated with sensors to monitor vital signs and an athlete management system to handle data input, storage, analysis, and accessibility for athletes.

The project has advanced through the efforts of a multidisciplinary team, which includes biomedical engineering undergraduates, two faculty …

Uv-A Light: A Novel Method For Food Dehydration, Mckade S. Roberts

All Graduate Theses and Dissertations, Fall 2023 to Present

Dehydration is one of the most prevalent forms of food preservation, with approximately 85% of food is hot air drying due to the simplicity of the process. The high temperatures employed in this method may also induce a loss in nutritional quality, which involves destruction of micronutrients (vitamins), and loss of color.

The aim of this work is to develop a low energy, non-thermal method of food dehydration that results in a high-quality product through the application of Ultraviolet light, within the UV-A range. UV light can be separated into its 3 categories based on the wavelength of light from …

Novel Kinetic Description Of Real-Time Polymerase Chain Reaction Characterizes Interrelated Effects Of Sample, Master Mix, And Cycle Time, David Tafur

All Graduate Theses and Dissertations, Fall 2023 to Present

Real-time quantitative polymerase chain reaction fluorescent curves are influenced by the quantification method, template length, primer sequence, polymerase activity, reaction conditions, and unwanted side reactions. Interpretation of these curves depends on understanding the subjacent mechanisms by which those factors can alter the curve profile, particularly on highly diluted analytes or impure samples. However, such factors are individually described today, or their interplay is not fully developed. The present work examines the effect of primer dimer formation and extension, resource competition, template reannealing, and polymerase thermodegradation, in addition to novel descriptions of polymerase competitive inhibition, extended primer amplification, and the probability …

Environment And Response Of 3d-Encapsulated Mesenchymal Stem Cells To Mechanical Loading, Augustus Greenwood

McKelvey School of Engineering Graduate Student Theses & Dissertations

This thesis explores the micromechanical environment induced when cyclically compressing hydrogels via finite element modeling and experimentally on the impact of loading on mesenchymal stem cells (MSCs) when encapsulated withing 3D hydrogel matrices. Degenerative joint diseases, characterized by cartilage degradation, present significant challenges due to cartilage's limited self-repair capacity. Innovative approaches, including stem cell-based therapies and engineered biomaterials, have emerged as promising strategies for cartilage repair and regeneration. This work specifically investigates the calibration of a bioreactor, the uniformity of load response across the hydrogel constructs via finite element modeling (FEM), and the stress response of MSCs subjected to various …

Utilizing Spatial Transcriptomics To Compare Gene Expression In Volumetric Muscle Loss Injury Recovery, Colton Gattis

Biomedical Engineering Undergraduate Honors Theses

Volumetric Muscle Loss (VML) injuries are known to disrupt the normal regenerative process via fibrosis leading to an extensive permanent loss of muscle function. The specific causation of this disruption remains to be defined; however, with new developments in transcriptomics, genetic trends can be identified across regions of tissue over time. This study follows VML injuries within the tibialis anterior of a mouse model for fifteen days after initial injury to attempt to identify expected transitions in healing. Genetic presence began to become more diversified as recovery progressed from four to fifteen days post injury with spatial clusters becoming globalized …

Photo-Carbon Monoxide Releasing Molecules For Antibacterial Benefits In Vascular Grafts, Beste Caner

Theses and Dissertations

Globally, the annual hemodialysis procedures surpass 1.5 million, emphasizing the vital role of reliable vascular access methods. However, common challenges like access infections and clot-induced blood flow reduction necessitate innovative solutions. This study delved into the potential therapeutic role of carbon monoxide (CO) and its effects on both endothelialization and non-pathogenic bacteria causing infections. The primary focus was evaluating the impact of loading different concentrations of carbon monoxide-releasing molecules (CORMs), specifically CORM diketone 4 (DK4), within 2D spin-coated films on cultured E. coli and endothelial cells. Initial assessments of CO release kinetics from DK4-loaded films demonstrated that the 10% condition …

Database And Machine Learning Model For Classifying Autism Spectrum Disorder From Smartphone Based Electroretinography, Rory Harris

Honors Scholar Theses

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder that negatively affects a patient’s cognitive and communication aptitude and, therefore, can severely impact that patient’s quality of life. Because of this, early diagnosis is paramount. In recent studies, electroretinography (ERG), which is a measure of the retina’s electrical response to a brief flash of light into the eye, has shown promise in detecting ASD. Access to these scans can provide early diagnosis, improving well-being. Current ERG devices are very expensive due to their on board processing capabilities. This paper aims to create an ERG device using a smartphone as the main …

On-Demand Fabrication Of Piezoelectric Sensors For In-Space Structural Health Monitoring, Amanda White, Isaac Little, Anastasiya Artyuk, Nicholas Mckibben, Fereshteh Rajabi Kouchi, Claire Chen, David Estrada, Zhangxian Deng

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Inflatable structures, promising for future deep space exploration missions, are vulnerable to damage from micrometeoroid and orbital debris impacts. Polyvinylidene fluoride-trifluoroethylene (PVDF-trFE) is a flexible, biocompatible, and chemical-resistant material capable of detecting impact forces due to its piezoelectric properties. This study used a state-of-the-art material extrusion system that has been validated for in-space manufacturing, to facilitate fast-prototyping of consistent and uniform PVDF-trFE films. By systematically investigating ink synthesis, printer settings, and post-processing conditions, this research established a comprehensive understanding of the process-structure-property relationship of printed PVDF-trFE. Consequently, this study consistently achieved the printing of PVDF-trFE films with a thickness of …

An In Vitro Investigation Of Urothelial Cell Function In Response To Hypoxia And Pressure In Relation To Bladder Outlet Obstruction, Britney Hudson

All Dissertations

Bladder outlet obstruction (BOO) is a prevalent urological condition and can be characterized by the presence of lower urinary tract symptoms (LUTS), such as hesitancy, weak stream, and nocturia. The main cause of BOO is a partial blockage of the urethra, which results in elevated voiding pressure, high storage pressure, and tissue ischemia, which are thought to be the triggers of bladder inflammation and subsequent fibrosis. Often patients do not seek treatment until the conditions get severe. Thus, it would be ideal to have an early diagnostic tool to detect changes in the bladder due to BOO. Extracellular vesicles (EVs) …

Locally Injectable Peptide Hydrogel For Conversion Of Temozolomide And Codelivery Of Sirna In Glioblastoma Multiforme Treatment, Megan Pitz

All Dissertations

Traditional treatment methods for glioblastoma multiforme (GBM) are largely unsuccessful, with a 5-year survival rate of 5.6%. Temozolomide (TMZ), the only chemotherapy FDA-approved for GBM treatment, is a hydrophobic prodrug that is stable in an acidic pH and begins converting to its active form at a physiological pH of 7.4. However, complete conversion of TMZ is observed only at a higher pH, and only about 30% of administered TMZ reaches the central nervous system. Therefore, there is a need for new treatment methods that maximize TMZ delivery to and efficacy at the tumor site. Self-assembling peptides are a unique class …

Tin-Silver As A Novel Biodegradable Metallic Biomaterial, Charley Goodwin

All Dissertations

The Essure device is a non-hormonal, minimally-invasive, permanent female sterilization implant, removed from the market due to an increase in adverse events, hypothesized to be caused by corrosion of the Sn-Ag component of the implant. The goals of this dissertation were to first develop implant retrieval methods for Essure devices and surrounding tissue, documenting signs of degradation and metallic degradation products, then to characterize the electrochemical behavior of Sn-Ag in biologically representative environments and finally, to assess the biological interaction of Sn-Ag. Retrieval analyses developed successful methods, qualifying the degree of corrosion, primarily of the Sn-Ag component and finding Sn …

Mammary Epithelial Cell Derived Extracellular Vesicles Influence Tumorigenic Phenotype Suppression In Her2-Positive Breast Cancer Cells, Brenda Okereke

All Dissertations

On a global scale, breast cancer remains the most commonly diagnosed cancer in the world. In 2020 alone, there were over 2.3 million new cases of breast cancer seen and a total of 685,000 deaths globally, this represents 16% or 1 in every 6 cancer deaths seen in women. By 2040 it is projected that the breast cancer burden will rise by over 40% to exceed 3 million new cases a year. Further understanding of the underlying biology and mechanisms behind tumor progression and breast cancers such as HER2+ breast cancer would allow for new therapeutic treatment targets to emerge. …

Development Of Advanced Simulator-Based Metrics For Suturing Skills Assessment And Feedback, Simar Singh

All Dissertations

Vascular surgery demands highly skilled suturing to manipulate and connect delicate vasculature. However, inadequate methods for open suturing skills training necessitate efficient and objective methods to develop skills. To address this need, medical training simulators for objective surgical skills training are gaining popularity for their formative assessment.

This research details the development of a system to classify suturing performance and provide feedback on a suturing skills measurement and feedback platform (called the SutureCoach). The SutureCoach simulator offers a comprehensive assessment of skill through sensors measuring needle driver motions, membrane forces and torques, subcutaneous suture needle movement, and hand motions. We …

Mesenchymal Stromal Cell Response To Degenerated Intervertebral Disc-Like Ph, Kyle Cannon

All Dissertations

Intervertebral disc degeneration (IVDD) has become increasingly prevalent and is a common contributing factor to low back pain. There are currently no clinical treatment options for IVDD that alleviate the symptoms of IVDD while simultaneously promoting repair of IVD tissue. One treatment option being explored is intradiscal administration of mesenchymal stromal cells (MSCs). However, the microenvironment of the degenerating IVD places significant stress on both native IVD cells and implanted cells. There are several questions that need to be addressed which may help further inform the development of efficacious intradiscal MSC therapies for IVDD. These questions include: 1) Do MSCs …

Identifying Temporomandibular Disorder Morphological Risk Factors Via Explainable Deep Learning And Multiscale Biomechanical Modeling, Shuchun Sun

All Dissertations

Clarifying multifactorial musculoskeletal disorder etiologies supports risk analysis and development of targeted prevention and treatment modalities. Deep learning enables comprehensive risk factor identification through systematic analysis of disease datasets but does not provide sufficient context for mechanistic understanding, limiting clinical applicability for etiological investigations. Conversely, multiscale biomechanical modeling can evaluate mechanistic etiology within the relevant biomechanical and physiological context. We propose a hybrid approach combining 3D explainable deep learning and multiscale biomechanical modeling; we applied this approach to investigate temporomandibular joint (TMJ) disorder etiology by systematically identifying risk factors and elucidating mechanistic relationships between risk factors and TMJ biomechanics and …

Novel Nucleus Pulposus Biomaterial Development And Low Field Mri Assessment For Intervertebral Disc Degeneration, Mario Krussig

All Dissertations

Intervertebral disc degeneration (IVDD) is a prominent pathology in the modern world that causes debilitating pain for many patients. The onset of IVDD occurs in the nucleus pulposus (NP). NP biomaterials will play a vital role in mitigating the progression of IVDD. Within this work, we sought to synthesize a solubilized extracellular matrix (ECM)-based NP biomaterial. Utilizing pepsin or urea extraction, bovine NP ECM was successfully solubilized (SBNPs). SBNP formulations were characterized biochemically, evaluated for cytotoxicity, and down-selected for front-running formulations. Leading candidate SBNPs were incorporated into an alginate bead biomaterial model to determine the potential bioactivity with human adipose-derived …

Modeling Of Nk Cells In Pediatric Patients With Unusually Severe Or Recurrent Hsv Using High-Dimensional Flow Cytometry, Yunran Feng

McKelvey School of Engineering Graduate Student Theses & Dissertations

HSV infection is broadly spread all over the world with some patients having severe and/or recurrent HSV infections. Our lab studies human Natural Killer (NK) cells, which are important in innate immune responses to viral infections and tumors. A publication in 2013 by Ornstein et al from our lab studied HSV+ pediatric patients and found some associations between severe infection and defects in NK cytolytic function. PLCG2 haploinsufficient variants found in 2 HSV patients causing PLCγ2 hypophosphorylation, and loss of cytolytic function in NK cells is a novel finding recently published by Alinger et al from our lab in 2023. …

Quantification Of Age-Related Changes In The Structure And Mechanical Function Of Skin With Multiscale Imaging, Alan E. Woessner, Nathan J. Witt, Jake D. Jones, Edward A. Sander, Kyle P. Quinn

Biomedical Engineering Faculty Publications and Presentations

The mechanical properties of skin change during aging but the relationships between structure and mechanical function remain poorly understood. Previous work has shown that young skin exhibits a substantial decrease in tissue volume, a large macro-scale Poisson’s ratio, and an increase in micro-scale collagen fiber alignment during mechanical stretch. In this study, label-free multiphoton microscopy was used to quantify how the microstructure and fiber kinematics of aged mouse skin affect its mechanical function. In an unloaded state, aged skin was found to have less collagen alignment and more non-enzymatic collagen fiber crosslinks. Skin samples were then loaded in uniaxial tension …

The Role Of Voluntary Descending Control In Enhancing Motor Function Via Transcutaneous Spinal Cord Stimulation, Yoon Kim

McKelvey School of Engineering Graduate Student Theses & Dissertations

Spinal cord injury (SCI) is a life-changing event that causes lasting motor impairments. Transcutaneous spinal cord stimulation (tSCS), a non-invasive form of neuromodulation in which electrodes are placed on the skin and used to stimulate the spinal circuits via an electrical current, has demonstrated positive effects on motor function recovery in individuals who have had SCIs. However, the precise mechanism of how tSCS interacts with voluntary descending drive remains poorly understood. This study aims to investigate the role of voluntary descending control in influencing reflex responses triggered by tSCS.

Electromyography (EMG) recordings were performed in ten unimpaired individuals while they …

Development Of A Wearable Short-Wave Infrared Photoplethysmography Device For Detection And Monitoring Of Hemodilution During Postpartum Hemorrhage, Hannah Gruensfelder

McKelvey School of Engineering Graduate Student Theses & Dissertations

ABSTRACT OF THE THESIS

A Thesis on the Development of a Wearable Short-Wave Infrared Photoplethysmography Device for Detection and Monitoring of Hemodilution During Postpartum Hemorrhage

by

Hannah Gruensfelder

Master of Science in Biomedical Engineering

Washington University in St. Louis, 2024

Professor Christine O’Brien, Chair

Postpartum hemorrhage (PPH), the leading cause of maternal death and morbidity, affects nearly 14 million people worldwide each year, disproportionally impacting racial minorities and people in low resource settings. A timely diagnosis of PPH is key in providing optimal patient care, as an estimated 90% of deaths due to PPH are preventable with early diagnosis and …

Characterizing The Molecular And Cellular Changes Of Senescent Cells Induced By Diverse Stressors In 2d And 3d Microenvironments, Apoorva Chauhan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Aging is a risk factor for myriad diseases and is often associated with the accumulation of senescent cells. Cellular senescence, a process of irreversible cell cycle arrest, is associated with various changes in cellular morphology and function. While senescence will occur naturally in a time-dependent manner, it can be prematurely induced by various extrinsic and intrinsic factors. Most senescence studies model cell behavior in two-dimensional (2D) microenvironments; however, these models are not physiologically relevant. In this study, the effects of naturally occurring reactive oxygen species (ROS) hydrogen peroxide (H2O2) and commonly used chemotherapy drugs, doxorubicin and palbociclib, on cellular senescence …

Development And Evaluation Of A Modeling Platform For Evaluating Immunotherapeutic Efficacy In The Tumor Microenvironment., Dylan Andrew Goodin

Electronic Theses and Dissertations

The tumor microenvironment (TME) represents the complex outcome of numerous tumor, stromal, and immune interactions, and whose composition can significantly affect treatment response. Particularly, immunotherapeutic efficacy is subject to multiple tumor-specific TME interactions that may be difficult to evaluate/predict clinically. Mathematical modelling has been formulated to evaluate specific aspects of the TME, including vasculature, ECM deposition, and immune-tumor interactions. However, the computational challenge of simulating multiple TME interactions has led to sacrificing varying degrees of model generalizability and clinical relevance. This work describes increased computational performance of a 3D continuum model that simulates tumor tissue, ECM, and vasculature using a …

Investigating Endothelial Damage During Ischemic Stroke Treatment Using In Vitro And Computational Models, Zackary Lorton

Theses and Dissertations

Large vessel occlusion during acute ischemic strokes requires mechanical thrombectomy (MT) procedures using stent retrievers (SR). However, complete clot removal typically takes several attempts, which can amplify endothelial cell injury (EI). This project aims to characterize the extent of EI during MT using an in vitro vascular platform and a finite-element model (FEM). Impact of SR diameter and characterization of SR mechanical forces are assessed and correlated with human umbilical vein endothelial cell (HUVEC) response. HUVECs were seeded on fibronectin (4 µg/cm²) coated true-scale PDMS arterial phantoms with 2.5 mm luminal diameter. Test groups (n=6) either …

Controlled Delivery Of Peptide And Gasotransmitter For Promoting Vascular Endothelialization, Shirin Changizi

Theses and Dissertations

Endothelial cells (ECs) are vital for maintaining proper vascular function and regulating processes such as hemostasis and inflammation. Disruption of endothelial cells integrity can lead to several pathological conditions, including coronary artery disease, vascular cognitive impairment, and dementia (VCID). Alterations in ECs distribution may lead to compromised blood-brain barrier (BBB) function, facilitating the passage of blood components and contributing to conditions such as Alzheimer's disease. Additionally, disruptions in ECs function can lead to early-stage thrombosis and intimal hyperplasia, resulting in graft failure in small-diameter (

This study aimed to develop innovative approaches for drug delivery to the BBB and TEVGs …

Broadening The Application Range Of Cell-Free Protein Expression Systems, Matthew Becker

All Theses

Centralized protein manufacturing platforms make the delivery of needed therapies to places with limited infrastructure almost impossible. Cell-free protein expression systems, systems that utilize protein production machinery extracted from cells, offer these communities a viable protein expression platform that is robust and easily deliverable to the place of need. Much work in cell-free system engineering looks to increase the hardiness of cell-free system (CFS) components, like the extract and reaction buffer, needed to carry transcription and translation of gene therapeutic targets forward. Freeze- and air-drying of extract, reaction buffer, or both with certain additives, like sugar molecules, has been proposed …

Advancements Of A Breast Tissue Marker And Localization System, Azrin Jamison

All Theses

Breast cancer has become the most prominent cancer worldwide in women. Annual mammograms are encouraged for women of high risk to increase early detection allowing for lumpectomies rather than mastectomies to occur. Prior to a lumpectomy, a biopsy must be taken to determine if the tissue is cancerous, and a breast cancer biopsy marker (BBM) is left in the region of possible cancerous tissue. Wire localization has been the gold standard for localizing these BBMs. However, due to the reported patient discomfort and logistical inefficiencies faced by healthcare providers (HCP), non-wire localization solutions have been recently developed. This study aims …