Biomedical Engineering and Bioengineering Commons^™

Exploring Ph Gradient Phenomena In Non-Linear Electrokinetic Microfluidic Devices, Azade Tahmasebi

Dissertations, Master's Theses and Master's Reports

Electrokinetic microfluidics is a versatile technology utilized within lab on a chip (LOC) devices for diagnostic and analytical applications; advantages include reduced resource demands, flexibility, and simplicity of use. Dielectrophoresis (DEP) is a precision nonlinear electrokinetic tool utilized within microfluidic microdevices to induce polarization and control bioparticle motions for applications that range from hemoglobin separations to cancer cell isolation and detection. Despite promising results, undesired side phenomena can occur in electrokinetic systems which impede reproducibility and accuracy. These unfavorable phenomena have not been comprehensively explored in the literature. Prior preliminary research suggests the fundamental phenomena originate from microelectrodes utilized in …

An Acute Respiratory Distress Syndrome Drug Development Collaboration Stimulated By The Virginia Drug Discovery Consortium, John S. Lazo, Ruben M.L. Colunga-Biancatelli, Pavel A. Solopov, John D. Catravas

Bioelectrics Publications

The genesis of most older medicinal agents has generally been empirical. During the past one and a half centuries, at least in the Western countries, discovering and developing drugs has been primarily the domain of pharmaceutical companies largely built upon concepts emerging from organic chemistry. Public sector funding for the discovery of new therapeutics has more recently stimulated local, national, and international groups to band together and focus on new human disease targets and novel treatment approaches. This Perspective describes one contemporary example of a newly formed collaboration that was simulated by a regional drug discovery consortium. University of Virginia, …

Editorial: Pulsed Electric Field Based Technologies For Oncology Applications, Siqi Guo, Gregor Sersa, Richard Heller

Bioelectrics Publications

No abstract provided.

Advancing Medical Technology For Motor Impairment Rehabilitation: Tools, Protocols, And Devices, Matthew Yough

Graduate Theses, Dissertations, and Problem Reports (ETD)

Excellent motor control skills are necessary to live a high-quality life. Activities such as walking, getting dressed, and feeding yourself may seem mundane, but injuries to the neuromuscular system can render these tasks difficult or even impossible to accomplish without assistance. Statistics indicate that well over 100 million people are affected by diseases or injuries, such as stroke, Parkinson’s Disease, Multiple Sclerosis, Cerebral Palsy, peripheral nerve injury, spinal cord injury, and amputation, that negatively impact their motor abilities. This wide array of injuries presents a challenge to the medical field as optimal treatment paradigms are often difficult to implement due …

Calpains In The Peripheral Nerve And During Demyelination And Degeneration In Rodents, John A. Miller

Browse all Theses and Dissertations

Myelin formed around axons ensures rapid and efficient action potential propagation. Disruption of myelinated axons in the peripheral nervous system (PNS) often causes nerve conduction failure, neurological symptoms and can lead to long-term disability. Calpains are calcium dependent cysteine proteases that play many roles during both normal physiology and pathogenesis. Calpain-1 (CAPN1) and calpain-2 (CAPN2) are key calpain paralogs found in the nervous system and potentially have opposing roles, with CAPN2 having a more neurodegenerative function. In the central nervous system (CNS), calpains have a role in developmental myelination as well as in the pathological demyelination of multiple sclerosis and …

Mouthpiece For Patients With Neuromuscular Disorders, Rebekah Starkey, Carissa Thompson, Michael Dickens, Andrew Pero

Williams Honors College, Honors Research Projects

Neuromuscular Disorders (NMDs) impact people throughout the world. An early hallmark of these disorders includes some degree of facial muscle weakness. Respiratory testing is important to evaluate the progression of these patients’ NMDs. However, these tests require that the patient purses their lips around a mouthpiece to create a tight seal. This is a difficult task for one with facial muscle degeneration. This often leads to results that fail to reflect the patient’s true respiratory ability and prevents their physician from providing the appropriate degree of care. The objective of this project was to develop a face mask or mouthpiece …

Verification Of Proton Range Predictions In Proton Treatment Planning Using X-Ray Ct Or Proton Ct Imaging, Nicholas S. Yee

Graduate Research Theses & Dissertations

The objective of this paper is to compare the range errors for two treatment plans; one using x-ray CT and the other using proton CT for calculating dose distributions in an animal tissue phantom. We shot 150 MeV proton beam through a meat phantom to a film stack to measure the exponential drop of dose at the Bragg peak until zero dose remained. Plotting the depth dose curves and performing gamma analyses are two ways to quantify the proton range errors when comparing them to depth dose curves from film measurements in the phantom. The depth dose curves give us …

Side Cutting Biopsy Needle For Endoscopes, Cade Smarr, Ella B. Brinkman, Christine Skakun, Vincent Grosso

Williams Honors College, Honors Research Projects

Develop a side cutting biopsy needle that fits through the working channel of the endoscope similar to stereotactic needle with syringe suction to overcome the small biopsy samples due to instrument size limitations. The problem users are facing is that the biopsy samples through the endoscope are small secondary to instrument size limitations. The idea for this problem is to develop a side cutting biopsy needle that fits through the working channel of the endoscope similar to stereotactic needle, syringe suction.

Enhancing Dental Aligners With Direct 3d Printing Manufacturing, Erin Clark, Lauren Ickes, Tyler Madison

Williams Honors College, Honors Research Projects

Replacement of thermoforming with direct 3d printed aligners, molding appliances for dental and alveolar movement. Currently the process involved requires 3d printing models and plastic thermoforming, trimming and polishing to fabricate the end product. If possible a product that could be 3d printed that had stress retention, crack resistance, and stain resistance properties delivered in thickness between .030 and .040 inches.

Frostflex, Isaac Edmondson, Caleb Edmondson, Joey Esker, Nadine Salem

Williams Honors College, Honors Research Projects

Research has shown that the majority of heat lost during physical exercise leaves the body through the hands, feet, and the face. Our design project seeks to develop cooling glove technology to increase the rate at which heat leaves the body during recovery from physical exertion. The goal of this project was to investigate different ways in which heat absorption through various mediums can be manipulated and scaled into an adaptable, flexible design in which athletes of all levels, from recreational to professional, can improve their physical performance with the use of our gloves. Deliverables include a functional prototype, product …

Kv2.1 Dysfunction Underlies The Onset Of Symptoms In Sod1-G93a Mouse Model Of Als, Andrew J. Deutsch

Browse all Theses and Dissertations

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease which targets motoneurons (MNs), yet underlying disease mechanisms are not well understood. Evaluating the intrinsic excitability of MNs in ALS could lead to a better understanding of mechanisms causing neurodegeneration. The SOD1-G93A (SOD) model is the most commonly studied animal model of ALS. However, past studies have shown highly conflicting results on SOD MN excitability. Interestingly, I show that depending on the level of membrane depolarization, SOD MNs show opposite results of both hyper- and hypo-excitability. This reveals that differences in the methodology of measuring excitability can heavily impact the study results. …

Lipin1 Improves Membrane Integrity In Dystrophic Muscles Of Mdx Mice, Abdulrahman Jama

Browse all Theses and Dissertations

Duchenne muscular dystrophy (DMD) is an X-linked genetic disorder that affects 1 in 3500 male births worldwide. It is characterized by mutations in the dystrophin gene that results in the loss of functional dystrophin. Dystrophin deficiency leads to instability of the sarcolemma alongside increased inflammation, necrosis and fibrosis resulting in membrane rupture and eventual muscle fiber death. There are currently no effective treatments for DMD. Here we show that Lipin1 expression is significantly downregulated at the mRNA and protein levels in gastrocnemius muscle of mdx mice, the DMD mouse model. Lipin1 has a dual function as a phosphatidic acid phosphatase …

Dna Instability At (Attct) Microsatellites In Human Cells, Venicia Alhawach

Browse all Theses and Dissertations

Microsatellites are short tandem repeats of DNA (1-9 nucleotides) that are unstable in the genome. They can expand and contract which leads to mutations and rearrangements that jeopardize genomic integrity. When encountered by a replication fork, repeats of these microsatellites can form non-B DNA structures which cause replication forks to stall and collapse eventually leading to double stranded breaks (DSBs) and replication stress. One form of repair of replication dependent DSBs happens via break induced replication (BIR), a highly mutagenic repair pathway. The main objective of this study is to understand how ATTCT pentanucleotide repeats affect replication and chromosomal instability …

Microsatellite Induced Genomic Instability And Mutagenesis Through Break Induced Replication, Rujuta Yashodhan Gadgil

Browse all Theses and Dissertations

Faithful DNA replication is essential to maintain genomic integrity. Compromises in this process are among the prime causes of cancer and other genetic disorders. Among several factors that can interfere with error-free DNA replication, the formation of non-B DNA structures by microsatellite sequences is critical. Microsatellites are 1-9 bp long tandem repetitive regions that can form secondary structures like hairpins, triplex, Gquadruplex etc. and undergo expansions due to replication fork stalling to cause several diseases. Hairpin forming microsatellites have been shown to induce DNA DSBs and lead to genetic instability and mutagenesis. The goal of this study is to understand …

Impacts Of Diverse Inflammatory Stimuli On Neutrophil Behavior: Extracellular Vesicles, E-Cigarettes, And Nanoparticles, Hunter T. Snoderly

Graduate Theses, Dissertations, and Problem Reports (ETD)

Neutrophils are the body’s front-line defenders against foreign insult and are key players in a variety of inflammatory conditions. This body of work examines the role of neutrophils in promoting pathology in three distinct inflammatory contexts. In the pro-inflammatory state provoked by breast cancer, neutrophils decondense their nuclei and release cytotoxic web-like structures known as neutrophil extracellular traps (NETs). NETs form most commonly via histone modifications facilitated by the enzyme PAD4. NETs are known to be a harbinger of disease progression and promote metastasis through capture of circulating tumor cells. It was hypothesized that breast tumors release small particles known …

Longitudinal Oxygen Imaging In 3d (Bio)Printed Models, Ryan Curtis O'Connell

Graduate Theses, Dissertations, and Problem Reports (ETD)

Electron paramagnetic resonance (EPR), and its molecular imaging modality, is a powerful tool to noninvasively map various biological and chemical markers within objects of interest. Reliable data acquisition is a major impeding factor for longitudinal hands-off measurements. Measurements are especially challenging in biomedical applications, as live objects are not static. Frequent changes occur that require constant fine recalibration of the EPR detection system, called the resonator. To enable longitudinal imaging, a technology permitting automatic digital control of resonator coupling, tuning, and EPR data acquisition was developed. Automation was achieved through the utilization of a microcontroller and digital peripheral components such …

Evaluation Of Changes In Cellular Behavior Upon Exposure To Selected Analytes Used In Synthetic Applications, Olivia L. Rose

Graduate Theses, Dissertations, and Problem Reports (ETD)

Metal-organic frameworks (MOFs) are organic crystalline hybrids that have been used for a variety of applications from catalysis to gas storage and drug delivery. Studies have shown that generally, while such frameworks are more biocompatible than similar aspect ratio nanostructures, they are also more prone to transformation and disintegration due to their flexible and fragile nature as resulted from the structure assembly and implemented structure-function relationships. With extensive previous literature showing that materials with nano dimensions such as carbon nanotubes, quantum dots and other nanomaterials have unique physicochemical properties that lead to increased biosystems’ reactivity. With increasing concerns regarding adverse …

An Experimental Study On The Mechanical Properties And Chemical Composition Of Lcd 3d Printed Specimens, Sebastian Gomez

College of Graduate Studies: Theses & Dissertations

Additive manufacturing technologies have been enhanced throughout the years yet have surprised the manufacturing industry due to their high-end surface finish and dimensional accuracy. Different experiments have been done to identify a specific phenomenon known in the vat-polymerization field. Distortion and dimensional inaccuracy tend to affect the overall properties of the process, either physical or chemical. This approach allows the understanding of how the physical properties have been affected and how to study the chemical properties to avoid this type of phenomenon. The chemical reaction between polymer and UV light has been studied and experimented with to the point that …

Synthesis And Processing Of Pcl And Irdye Nanoparticles For Application In Drug Release Mechanism, Michael Adeniyi

College of Graduate Studies: Theses & Dissertations

The objective of this study is to produce core-shell nanoparticles utilizing PCL and IRDye and investigate the nanoparticle release mechanism. Biodegradable polymer, Polycaprolactone (PCL), was electrosprayed separately with two types of IRDye, NHS and Dextran Texas red. The solution of PCL was formed by mixing PCL in a solution of 9.47ml Acetic Acid, 9.47ml Formic Acid, and 1.05ml Trifluoroethanol, following a ratio of 9:9:1. The two solutions of IRDye were prepared by mixing 2mg of the IRdye with 20ml of DMF at a rate of 0.1mg/ml.

The NHS IRDye was electrosprayed coaxially with PCL and the Dextran Texas red dye …

Characterization And Decoding Of Speech Activity From Intracranial Signals, Pedram Zanganeh Soroush

Theses and Dissertations

Speech is the first and foremost means of human communication. Millions of people worldwide suffer from severe speech disorders due to neurological diseases such as amyotrophic lateral sclerosis (ALS), brain stem stroke, and severe paralysis. A speech neuroprosthesis that decodes speech directly from neural signals could dramatically improve life for these individuals. Recent studies have demonstrated that it is possible to decode and synthesize various aspects of acoustic speech directly from intracranial measurements of electrophysiological brain activity. For those who have completely lost the ability to speak, the objective is to synthesize acoustic speech directly from brain activity during imagined …

Advanced Modeling And Innovative Transcranial Magnetic Stimulation Coil Designs For The Treatment Of Neurological Disorders, Mohannad Tashli

Theses and Dissertations

Transcranial magnetic stimulation (TMS) is a safe, effective and non-invasive treatment for several mental and psychiatric disorders. TMS is an FDA approved treatment and is commonly applied to patients who do not respond to medications for the treatment of clinical depression, smoking cessation, obsessive-compulsive disorder and migraine. Recently, there has been an increase in the development of electromagnetic neuromodulation techniques targeted at enhancing the effectiveness of TMS devices for the treatment of mental diseases. In TMS stimulation, focality is an important factor which determines the specificity of the pulses induced in different brain tissues. The electromagnetic pulses must be confined …

การพัฒนาไฮโดรเจลเจลาตินที่มีอนุภาคนาโนทองคำ สำหรับการวัดปริมาณรังสี, ภาวิณี ชูสินธ์

Chulalongkorn University Theses and Dissertations (Chula ETD)

ปัจจุบันรังสีรักษามีบทบาทสำคัญในการช่วยรักษาโรคมะเร็ง โดยการให้ปริมาณรังสีสูงสุดที่เนื้อเยื่อมะเร็ง และก่อให้เกิดผลกระทบต่อเนื้อปกติน้อยที่สุด ดังนั้นความถูกต้องของปริมาณรังสีจึงเป็นสิ่งสำคัญ การวัดปริมาณรังสีเป็นสิ่งหนึ่งที่ช่วยยืนยันและสร้างความมั่นใจให้ผู้ป่วยได้ การศึกษาวิจัยนี้ได้พัฒนาอุปกรณ์การวัดปริมาณรังสีในรูปแบบไฮโดรเจลชนิดใหม่ สำหรับการวัดปริมาณรังสี ที่มีคุณลักษณะเฉพาะตัวในการขึ้นรูปได้หลายมิติ และมีความเข้ากันได้ทางชีวภาพจากพอลิเมอร์ธรรมชาติ เช่น เจลาตินและอะกราโรส ผสมกับสารละลายทองคำ โดยอาศัยนวัตกรรมนาโนเทคโนโลยี และการเปลี่ยนแปลงปฏิกิริยาทางเคมีของไฮโดรเจลเมื่อมีการฉายรังสี ทำให้เกิดการสังเคราะห์อนุภาคนาโนทองคำที่มีคุณสมบัติทางแสงที่โดดเด่นและเฉพาะตัวเชิงพื้นผิว ทำให้มองเห็นการเกิดการเปลี่ยนแปลงสีของไฮโดรเจลด้วยสายตาเปล่าได้อย่างรวดเร็วภายใน 10 นาที ภายหลังจากการได้รับรังสี รวมทั้งวัดค่าการดูดกลืนแสงในช่วงปริมาณรังสี 0-5 Gy ด้วยเทคนิคสเปกโตรโฟโตเมตรีที่ความยาวคลื่นดูดกลืนสูงสุดที่ 540 nm พบว่า ปฏิกิริยาทางเคมีภายในไฮโดรเจลเกิดขึ้นได้สมบูรณ์เมื่อได้รับรังสีผ่านไปแล้ว 2 ชั่วโมง โดยมีขีดความสามารถในวัดต่ำสุด คือ 0.37 Gy โดยมีความคงตัวของค่าการดูดกลืนแสงหลังจากได้รับรังสีไปแล้วนานถึง 7-14 วัน รวมทั้งให้ค่าความสัมพันธ์เชิงเส้นตรงของไฮโดรเจลเจลาตินและไฮโดรเจลเจลาตินผสมอะกราโรส เท่ากับ 0.9996 และ 0.9994 ตามลำดับ จากผลการทดลองนี้แสดงให้เห็นถึงความสามารถของไฮโดรเจลชนิดนี้ในการตอบสนองต่อรังสีที่รวดเร็ว ในช่วงปริมาณรังสีต่ำที่ใช้ทางคลินิค ที่มีความคงตัวและความถูกต้องแม่นยำสูง เหมาะสำหรับการนำไปประยุกต์ใช้ในงานรังสีรักษาต่อไป

Assessment Of Material Properties In Bone Surrounding Microdamage, Niovi Dollas

Dissertations and Theses

Bisphosphonates [BPs] are the mainstay for osteoporosis treatment. They suppress bone resorption/remodeling, preventing bone loss. However, BPs also suppress the beneficial bone remodeling that replaces microscopically damaged bone that occurs from normal mechanical wear-and-tear or fatigue, leading to impaired tissue material properties and in some instances atypical femoral fractures.

In these studies, we assessed the effects of acute fatigue, fatigue induced remodeling, and fatigue microdamage with remodeling suppression using the clinical BP, alendronate [ALN], on local bone material properties. Studies were performed on cortical bone sections from rat ulnae into which fatigue damage had been introduced in vivo. Rat …

The Wound Healing And Antibacterial Properties Of Mesenchymal Stromal Cell Extracellular Matrix Nanoparticles, Emily N. Wandling

Theses and Dissertations

Treatments for acute respiratory distress syndrome (ARDS) are still unavailable and the prevalence of the disease has only increased due to the Covid-19 pandemic. Mechanical ventilation regiments are still utilized to support declining lung function, but they also contribute to lung damage and increase the risk of bacterial infection. The anti-inflammatory and pro-regenerative abilities of mesenchymal stromal cells (MSCs) have shown to be a promising therapy for ARDS. We propose to utilize the regenerative effects of MSC secretome and the extracellular matrix (ECM) into a nanoparticle. Our mouse MSC (MMSC) ECM nanoparticles were characterized using size, zeta-potential, and mass spectrometry …

Quantifying Fibronectin Mechanical Properties Using Antibody-Mediated Optical Tweezing (Amot), Caleb Dalton

Theses and Dissertations

Despite decades of investigations into fibronectin (FN) fibrillogenesis, fibril mechanics remain unclear. One of the most important roles for FN fibrils is in the arena of cellular mechanotransduction. Numerous studies have demonstrated that cells sense and respond to the mechanical properties of their surroundings; since FN fibrils are a major constituent of the ECM that links cells to their surroundings, mechanotransduction cannot be fully understood without understanding the mechanical properties of FN fibrils. In this proposal, a novel biomechanical assay is developed to probe isolated FN fibrils and quantify their response to specific loading conditions. This will be accomplished by …

Leveraging Cell-Substrate Adhesion And Cell Migratory Properties In Skeletal Muscle Constructs And Cancer Metastasis Assays, Lauren E. Mehanna

Theses and Dissertations--Chemical and Materials Engineering

Volumetric muscle loss (VML) remains one of the few skeletal muscle injuries without a reliable and repeatable treatment. In large volume muscle injuries, muscle fibers as well as the surrounding connective tissue are damaged, preventing therapeutic muscle stem cells, called myogenic progenitor cells (MPCs), from reaching the injury site and initiating repair. There is a clinical need to rapidly fabricate in vitro muscle tissue constructs that mimic the native tissue organization, with aligned myotubes, for insertion and integration at the patient’s injury site. In this dissertation, we utilize the MPC’s natural propensity to close gaps across an injury site to …

Identification Of Proteins Involved In Cell Membrane Permeabilization By Nanosecond Electric Pulses (Nsep), Giedre Silkuniene, Uma Mangalanathan, Alessandra Rossi, Peter A. Mollica, Andrei G. Pakhomov, Olga N. Pakhomova

Bioelectrics Publications

The study was aimed at identifying endogenous proteins which assist or impede the permeabilized state in the cell membrane disrupted by nsEP (20 or 40 pulses, 300 ns width, 7 kV/cm). We employed a LentiArray CRISPR library to generate knockouts (KOs) of 316 genes encoding for membrane proteins in U937 human monocytes stably expressing Cas9 nuclease. The extent of membrane permeabilization by nsEP was measured by the uptake of Yo-Pro-1 (YP) dye and compared to sham-exposed KOs and control cells transduced with a non-targeting (scrambled) gRNA. Only two KOs, for SCNN1A and CLCA1 genes, showed a statistically significant reduction in …

Biom 4760: Biomedical Engineering Design Principles (Syllabus), Carl D. Herickhoff

Biomedical Engineering Syllabi Archive

Course Description: Practical design methods emphasizing the front-end or concept development stage of engineering design; design a system, component, or process to meet desired needs within realistic constraints with functioning on multi-disciplinary teams.

Biom 3110(Honors): Medical Physiology (Syllabus), Bradford D. Pendley

Biomedical Engineering Syllabi Archive

Course Description: Basic principles of human physiology and how these are applied in medicine and biomedical engineering problem and devices; physiological principles using appropriate mathematical and engineering models to construct an understanding of how the body works as an integrated system.

Biom 1720: Introduction To Biomedical Engineering Tools (Syllabus), Stephen Strain

Biomedical Engineering Syllabi Archive

Course Description: Use of computer tools for data analysis, presentation, documentation; introduction to programming; individual and group design projects.