Engineering Commons^™

Shape Memory Alloy Capsule Micropump For Drug Delivery Applications, Youssef Mohamed Kotb

Theses and Dissertations

Implantable drug delivery devices have many benefits over traditional drug administration techniques and have attracted a lot of attention in recent years. By delivering the medication directly to the tissue, they enable the use of larger localized concentrations, enhancing the efficacy of the treatment. Passive-release drug delivery systems, one of the various ways to provide medication, are great inventions. However, they cannot dispense the medication on demand since they are nonprogrammable. Therefore, active actuators are more advantageous in delivery applications. Smart material actuators, however, have greatly increased in popularity for manufacturing wearable and implantable micropumps due to their high energy …

Mri Image Regression Cnn For Bone Marrow Lesion Volume Prediction, Kevin Yanagisawa

Theses and Dissertations

Bone marrow lesions (BMLs), occurs from fluid build up in the soft tissues inside your bone. This can be seen on magnetic resonance imaging (MRI) scans and is characterized by excess water signals in the bone marrow space. This disease is commonly caused by osteoarthritis (OA), a degenerative join disease where tissues within the joint breakdown over time [1]. These BMLs are an emerging target for OA, as they are commonly related to pain and worsening of the diseased area until surgical intervention is required [2]–[4]. In order to assess the BMLs, MRIs were utilized as input into a regression …

Development Of A Xenograft For Annular Repair Using Pulsed Electric Field Exposures For Enhanced Decellularization, Prince Mensah Kwaku Atsu

Theses and Dissertations

Severe back injuries and chronic pain necessitate surgical replacement of damaged intervertebral disc (IVD) cartilage in advanced disease stages. Bovine IVD tissue has been exposed to an upper threshold pulsed electric field (PEF) dose, causing cell death without thermal damage to the tissue. Subsequent PEF exposures at lower magnitudes have accelerated the removal of immunogenic biomolecules though electrokinetic extraction using optimized aqueous solutions. This approach yields a natural scaffold, ready for biocompatibility and mechanical strength assessment. The effects of microsecond pulsed electric fields (µsPEF) on primary bovine AF fibroblast-like cells have been characterized in vitro. PEFs of 10 and 100 …

Cancer Treatment By Targeting Hdac4 Translocation Induced By Microsecond Pulsed Electric Field Exposure: Mechanistic Insights Through Kinases And Phosphatases, Zahra Safaei

Theses and Dissertations

Epigenetic modifications, arising from sub-cellular shifts in histone deacetylase (HDAC) activity and localization, present promising strategies for diverse cancer treatments. HDACs, enzymes responsible for post-translational histone modifications, induce these epigenetic changes by removing acetyl groups from ε-N-acetyl-lysine residues on histones, thereby suppressing gene transcription. Within the HDAC group, class IIa HDACs are notable for their responsiveness to extracellular signals, bridging the gap between external stimuli, plasma membrane, and genome through nuclear-cytoplasmic translocation. This localization offers two significant mechanisms for cancer treatment: nuclear accumulation of HDACs represses oncogenic transcription factors, such as myocyte-specific enhancer factor 2C (MEF2C), triggering various cell death …

Borophene And Graphene For Non-Enzymatic Biosensor- Ab-Initio Study, Omar A. Ismail

Theses and Dissertations

Non-enzymatic glucose sensing holds promise to overcome limitations associated with glucose oxidase, such as oxygen dependence and short shelf life. This study explores the potential sensing capabilities of borophene and graphene through direct interaction with various compounds, including β-glucose, uric acid, ascorbic acid, fructose, and acetaminophen. Using Density Functional Theory (DFT), we calculated binding energies and the respective Density of States (DOS) for these adsorbates on both graphene and borophene surfaces. Preliminary results suggest that borophene might exhibit nearly twice the affinity for β-glucose compared to graphene. Moreover, the calculated Density of States reveals distinct distortions in the electronic states …

Process-Structure-Property Relationships Of Nanofibers For Biomedical Applications, Dipasree Bhowmick

Theses and Dissertations

This thesis explores the fabrication, characterization, and applications of nanofiber membranes utilizing Forcespinning® technology. Two distinct nanofiber systems were developed and evaluated, one focusing on pH-responsive Eudragit-baicalin loaded nanofibrous membranes for wound healing and the second one on thermo-responsive nanofiber-hydrogel (PNIPAAm) systems for biosensing applications, specifically dopamine detection. In the first project, nanofiber membranes loaded with Eudragit and baicalin demonstrated superior antibacterial properties against both gram-negative (E. coli) and gram-positive (B. meg) bacteria. Additionally, these membranes exhibited antioxidant properties and enhanced cell proliferation of 3TT cells, making them promising candidates for wound healing dressings. In the second project, a …

Deep Learning And Generative Ai Approaches For Automated Diagnosis And Personalized Treatment: Bridging Machine Learning, Medicine, And Biomechanics In Predicting Tissue Mechanics And Biomaterial Properties., Yasin Shokrollahi

Theses and Dissertations

Machine learning, particularly deep neural networks, has demonstrated significant potential in predicting high-dimensional tasks across various domains. This work encompasses a detailed review of Generative AI in healthcare and three studies integrating machine learning with finite element analysis for predicting biomechanical behaviors and properties. Initially, we provide a comprehensive overview of Generative AI applications in healthcare, focusing on Transformers and Denoising Diffusion models and suggesting potential research avenues to address existing challenges.

Subsequently, we addressed soccer-related ocular injuries by combining finite element analysis and machine learning to predict retinal mechanics following a soccer ball hit rapidly. The prediction errors are …

Evolutionary Conservation And Times Of Action Of Heterochronic Genes, Maria Ivanova

Theses and Dissertations

The heterochronic pathway of C. elegans is the most well-characterized system to date for controlling the sequence and timing of developmental events. However, we still have critical unanswered questions to address. First, little is known about the evolution of the heterochronic pathway, and of developmental timing in general. To determine if the roles of major heterochronic genes are conserved, I made mutants in orthologs of these genes in C. briggsae, using CRISPR/Cas9. My studies revealed a significant drift in the roles of some of the genes, although all of them are still involved in the developmental timing regulation, and several …

Advanced Processing Techniques For Electrospun Nanofibers: Investigating Annealing And Laser Zone-Drawing Effects On Material Characteristics, Matthew D. Flamini

Theses and Dissertations

Electrospun nanofibers hold potential for a wide range of commercial and scientific applications; however, their properties must be optimized through post-processing treatments to achieve optimal performance. This dissertation investigates the effects of annealing and laser zone-drawing on electrospun nanofiber properties. Annealing polycaprolactone nanofibers at 70°C results in the highest rate of crystallization and molecular alignment, impacting long-term stability and mechanical properties. A multivariate linear model incorporating crystallinity and molecular alignment predicts the material properties resulting from annealing under different conditions. Laser zone-drawing experiments reveal that polylactide fiber thinning under laser irradiation primarily occurs due to drawing rather than ablation. Steady-state …

The Effects Of Mechanical Strain On Vascular Calcification And The Canonical Wnt Pathway, Hannah E. Douglas

Theses and Dissertations

Cardiovascular disease is a significant health crisis, representing 32% of deaths worldwide in 2019. Vascular calcification (VC), a major contributor to cardiovascular disease, is a regulated biomineralization process whose exact mechanisms are unknown. Additionally, vascular smooth muscle cells (VSMCs) significantly contribute to VC by undergoing a phenotypic switch and differentiating into osteoblast-like cells. When factors like hypertension cause disturbed laminar flow in the body’s vasculature, the mechanical stress promotes the phenotypic switch and calcification of VSMCs via mechanotransduction. VC is also induced by the Wnt pathway, which is activated via mineral imbalance and mechanical stimulation. However, the exact mechanisms behind …

Chemical And Polymer Characterization Of The Potential Modes Of Degradation Of An Injectable Nucleus Pulposus Replacement Device, Antonio G. Abbondandolo

Theses and Dissertations

HYDRAFIL™ is a poly(vinyl alcohol)/poly(ethylene glycol)-based hydrogel nucleus pulposus replacement device that is injected in situ and has demonstrated efficacy in lowering the prevalence and pain associated with back. In this work, we developed a method to analyze HYDRAFIL™ polymer composition using (TGA) and characterized intermolecular bonding interactions within the hydrogel through (FTIR). To function as a permanent implant for nucleus pulposus replacement, HYDRAFIL™ must be stable when exposed to a multitude of degradation pathways, namely, thermal, chemical, and mechanical. We subjected HYDRAFIL™ to accelerated thermal and chemical degradation pathways and described compositional, physical and chemical property changes using a …

Methodology For Designing Assistive Robots For Activities Of Daily Living Assistance, Javier Dario Sanjuan De Caro

Theses and Dissertations

The growing prevalence of Upper or Lower Extremities Dysfunctions (ULED), often linked to central nervous disorders such as stroke, Spinal Cord Injury (SCI), and Multiple Sclerosis (MS), underscores the urgent need for innovative support solutions. Over 5.35 million Americans currently live with ULED, a situation that places a significant socioeconomic burden on families and society. Despite invaluable support from caregivers and family members, the need for more scalable, practical solutions persists.

Wheelchair-mounted assistive robots emerge as a promising alternative in this context. These devices, offering continuous and reliable assistance, significantly alleviate caregiver fatigue and enhance the independence and quality of …

Understanding Vascular Calcification Through The Lens Of Canonical Wnt Signaling, Karlee Mcneel

Theses and Dissertations

Every 37 seconds, someone in the United States dies from cardiovascular disease. Vascular calcification is one of the underlying causes of these fatal events. Medial calcification develops following arteriosclerosis, or hardening of the arteries. Medial calcification is characterized by the deposition of hydroxyapatite in the medial layer of the arteries after normal vascular smooth muscle cells undergo a phenotypic switch to resemble osteoblast-like cells. It is hypothesized that this switch is caused by the wingless related (WNT)-Signaling pathway. The WNT-Signaling pathway, upon activation, causes the upregulation of osteogenic markers for the development of osteoblast-like cells. Current treatments alleviate consequences of …

Characterizing Endothelial Damage During Ischemic Stroke Treatment With 3d Cerebrovascular Live Cellular And Finite Element Models, Ana Regina Martinez Dehesa

Theses and Dissertations

Stent retriever mechanical thrombectomy (SRMT) is part of the clinical standard-of-care for acute ischemic stroke (AIS) patients with large vessel occlusion (LVO). Endothelial injury (EI) is widely associated with SRMT. Studies report finding EI markers in over 50% of retrieved clots, suggesting the frequency of EI in MT patients is rather common. The mechanism of EI and its contribution to MT failure and clinical outcomes remain poorly understood because of a lack of techniques to observe EI and study it in vitro. This study aims to investigate the mechanisms of EI induced by SRMT, as well as the effect stent …

Detecting Physiological Concentrations Of Alzheimer’S Associated Amyloid-Β Protein Utilizing A Cell-Based Response, Brittany Elizabeth Watson

Theses and Dissertations

Alzheimer’s disease (AD) is characterized symptoms of cognitive impairment resulting from blood-brain barrier (BBB) breakdown and neuronal cell death. AD is associated with aggregated amyloid-β (Aβ) plaques deposited around brain vasculature and within the brain. Changes in the brain occur up to 20 years before symptoms arise; however, there is currently no pre-symptomatic detection method available for AD. An intact BBB requires tight junction proteins (TJs) that render relatively high transendothelial electrical resistance (TEER). AD-associated breakdown of the BBB correlates with vascular Aβ deposition, suggesting that aggregated, pathological Aβ can modulate TEER. We explore leveraging this cellular response for early …

Efficient Scopeformer: Towards Scalable And Rich Feature Extraction For Intracranial Hemorrhage Detection Using Hybrid Convolution And Vision Transformer Networks, Yassine Barhoumi

Theses and Dissertations

The field of medical imaging has seen significant advancements through the use of artificial intelligence (AI) techniques. The success of deep learning models in this area has led to the need for further research. This study aims to explore the use of various deep learning algorithms and emerging modeling techniques to improve training paradigms in medical imaging. Convolutional neural networks (CNNs) are the go-to architecture for computer vision problems, but they have limitations in mapping long-term dependencies within images. To address these limitations, the study explores the use of techniques such as global average pooling and self-attention mechanisms. Additionally, the …

An Epileptic Seizure Detection Method From Eeg Signals Based On A Classifier-Driven Feature Reduction Technique, Raymond N. Kamel

Theses and Dissertations

Epileptic seizure detection can improve the quality of life of epileptic patients, allow for more accurate medication, and minimize the risk of sudden unexpected death in epilepsy (SUDEP). This thesis work aims to develop a robust and stable algorithm for epileptic seizure detection through the classification of EEG signals. To achieve this aim, a methodology is proposed to develop a classifier that can differentiate between the healthy (normal), interictal, and ictal states of EEG signals, while maximizing the classification accuracy and minimizing the computational redundancy. The main pillar upon which this methodology is designed is using a problem-specific classifier-driven feature …

Polyethyleneimine Shell Nucleic Acid Nanostructures From Gold Nanoparticle Template For Chemotherapeutic Drug Delivery, Brendan Guy Rucci

Theses and Dissertations

The next generation of anticancer agents will emerge from rationally designed nanostructured materials. This work involved the synthesis and characterization of novel hollow DNA-conjugated gold nanoparticles (DNA-AuNPs) for controlled drug delivery. Polyethyleneimine (PEI) was bound to citrate-capped AuNPs, forming polymer-shell nanoparticles. Dissolution of the gold core via iodine formed hollow core polymeric nanoparticles (HCPPs) and a high density of DNA (85 molecules/particle) containing daunorubicin was conjugated. Particles were spherical with an average diameter of 105.7±17.3 nm and zeta potential of 20.4±3.54 mV. We hypothesize the DNA backbone electrostatically condensed to the primary amines on the surface of the particle toroidally, …

A 3d Bioprinted Hydrogel Microfluidic Device For Screening Applications, Anant Bhusal

Theses and Dissertations

The microfluidic enabled the integration of engineered miniaturized tissue models for drug screening. Conventional polydimethylsiloxane or plastic-based devices require multiple fabrication steps, which are challenging. We developed a 3D bioprinting approach to create prototypes of hydrogel-based multi-material microfluidic devices integrated with microtissue models. The approach utilizes poly(ethylene glycol) diacrylate and gelatin-methacryloyl to create microfluidic chips using multi-material bioprinting capacity with a high resolution of 15µm on x-y and 50µm on the z-axis and post-printing viability of >90%. We demonstrated easy regulation of stiffness from 24±5 kPa to 1,180±9 kPa and burst pressure from 16±1kPa to 256±19 kPa in the chip …

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 …

Investigating Tgf-Β1 And Fibronectin Signaling In Low Oxygen Environments, Caitlin E. Williams

Theses and Dissertations

Breast cancer is the second leading cause of death in women, second to lung cancer. It’s one of the most well-known cancers, with almost 300,000 new cases estimated to be diagnosed in 2023. Breast cancer often begins in ductal epithelial cells, and these cells will typically undergo a cellular transformation process known as epithelial-mesenchymal transition (EMT) in early stages. Breast cancer becomes deadly when it reaches a metastatic stage. As a part of the metastatic process, transformed cells will conduct remodeling of the extracellular matrix (ECM) to allow for migration of an otherwise non-migratory cell type.

As dense tumors form, …

Computational Modeling Of Temporal Eeg Responses To Cyclic Binary Visual Stimulus Patterns, Connor M. Delaney

Theses and Dissertations

The human visual system serves as the basis for many modern computer vision and machine learning approaches. While detailed biophysical models of certain aspects of the visual system exist, little work has been done to develop an end-to-end model from the visual stimulus to the signals generated at the visual cortex measured via the scalp electroencephalogram (EEG). The creation of such a model would not only provide a better understanding of the visual processing pathways but would also facilitate the design and evaluation of more robust visual stimuli for brain-computer interfaces (BCIs). A novel experiment was designed and conducted where …

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 …

Development Of A Crosslinked Osteochondral Xenograft And A Collagen Stabilizing Intra-Articular Injection To Remediate Cartilage Focal Lesions To Prevent Osteoarthritis, Mark Lewis Mosher

Theses and Dissertations

Osteoarthritis is one of the most common causes of disability in adults in America. It is a progressive and degenerative disease where the articular cartilage is broken down and lost from the surfaces of bones causing chronic pain and swelling in the joints, and currently has no cure. The most commonly osteoarthritis starts from a focal lesion on the cartilage surface, which will expand on the surface and downwards through the thickness of the tissue. The current gold standard for correcting cartilage focal lesions is the osteochondral autograft/allograft transplantation (OAT), which replaces the defect with a fresh osteochondral graft. The …

Oxidized Fibrin Alginate Microbeads To Treat Vascular Calcification, Brittany Nichole Macha

Theses and Dissertations

Calcification is linked to a high prevalence of cardiovascular events and mortality due to arterial stiffness. Stiffening of the arteries in the case of medial calcification is due to hydroxyapatite mineral deposited in the artery thus leading to the loss of elastin. A possibility of removing this rogue mineral along the vessel walls could be the use of osteoclasts. Osteoclasts, a type of osteocyte, have the unique ability to absorb bone in the bone turnover process. It is proposed that in the future, osteoclasts be delivered to the site of mineralization through oxidized alginate-fibrin microbeads. Alginate hydrogels have proven great …

Image-Based Cancer Diagnosis Using Novel Deep Neural Networks, Hosein Barzekar

Theses and Dissertations

Cancer is the major cause of death in many nations. This serious illness can only be effectivelytreated if it is diagnosed early. In contrast, biomedical imaging presents challenges to both clinical institutions and researchers. Physiological anomalies are often characterized by modest modifications in individual cells or tissues, making them difficult to detect visually. Physiological anomalies are often characterized by slight abnormalities in individual cells or tissues, making them difficult to detect visually. Traditionally, anomalies are diagnosed by radiologists and pathologists with extensive training. This procedure, however, demands the participation of professionals and incurs a substantial expense, making the classification of …

Importance Of Light Activation For Plant Cryptochrome And Antibacterial Drug Delivery Strategies, Merfat Ahmed Hammad

Theses and Dissertations

The goal of this project is to investigate the benefits of applying light in different systems. In the first part, the magnetoreception process that occurs in the light activated cryptochrome of Arabidopsis Thaliana was investigated. In the second part, photo-carbon monoxide releasing molecules (photo-CORMs) were investigated for their antibacterial effect to develop biomedical strategies. Overall, this has been achieved in three different studies. The first study investigated if the forward lightdriven reaction is involved in the magnetoreception process or not in cryptochrome (CRY). To accomplish this, the plant seedlings were tested for 90 minutes as follows: 5 minutes in the …

Deciphering The Firing Patterns Of Hippocampal Neurons During Sharp-Wave Ripples, Kourosh Maboudi Ashmankamachali

Theses and Dissertations

The hippocampus is essential for learning and memory. Neurons in the rat hippocampus selectively fire when the animal is at specific locations - place fields - within an environment. Place fields corresponding to such place cells tile the entire environment, forming a stable spatial map supporting navigation and planning. Remarkably, the same place cells reactivate together outside of their place fields and in coincidence with sharp-wave ripples (SWRs) - dominant electrical field oscillations (150-250 Hz) in the hippocampus. These offline SWR events frequently occur during quiet wake periods in the middle of exploration and the follow-up slow-wave sleep and are …

Investigating The Role Of Cryptochrome Activity In Arabidopsis Plant And Blue Light Exposure In Saos-2 Cell-Mediated Mineralization, Maria Nijr Albaqami

Theses and Dissertations

Cryptochromes (CRYs) are flavoproteins that absorb blue light and are associated with the perception of electromagnetic stimuli in a variety of organisms including animals and plants. When exposed to blue light, CRYs undergo flavin redox cycles and form radical pairs intermediates that are assumed to be magnetically sensitive as predicted by the radical-pair hypothesis. However, it is unknown if CRYs fulfill the criteria to act as biological magnetosensors. In the first aim, Arabidopsis thaliana seedlings were exposed to blue light and a time-dependent weak magnetic field at radiofrequency (RF) of 7 MHz as a diagnostic tool to test the radical-pair …

Bioactive Self-Forming Hydrogels For Biomedical Applications, Kirstene Arcuino Gultian Giddings

Theses and Dissertations

Hydrogels are soft biomaterials that feature a wide range of physical and biochemical properties. Although highly versatile, hydrogels typically require an exogeneous input (e.g., light, pH, temperature) to form, and this limits their use to conditions where a catalyst is present. The goal of this dissertation is to expand the use of catalyst-based hydrogels by developing hydrogels with independently tunable properties which gel in situ without external stimuli. This new class of hydrogels was developed by first modifying macromers with norbornene (Nor) or tetrazine (Tet) moieties. Macromers containing Nor or Tet remain liquid when dissolved, and upon mixing self-form into …