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 …

Rational Design Of Peptide-Based Materials Informed By Multiscale Molecular Dynamics Simulations, Dhwanit Rahul Dave

Dissertations, Theses, and Capstone Projects

The challenge of establishing a sustainable and circular economy for materials in medicine and technology necessitates bioinspired design. Nature's intricate machinery, forged through evolution, relies on a finite set of biomolecular building blocks with through-bond and through-space interactions. Repurposing these molecular building blocks requires a seamless integration of computational modeling, design, and experimental validation. The tools and concepts developed in this thesis pioneer new directions in peptide-materials design, grounded in fundamental principles of physical chemistry. We present a synergistic approach that integrates experimental designs and computational methods, specifically molecular dynamics simulations, to gain in-depth molecular insights crucial for advancing the …

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 …

Evaluation Of Polyvinyl Alcohol (Pva) For Electrospinning Utility In The Blood Vessel Mimic (Bvm) Lab, Logan Vandenbroucke

Master's Theses

Electrospinning has provided the opportunity to create extracellular matrix (ECM) mimicking scaffolds for the development of tissue-engineered constructs. Within Professor Kristen Cardinal’s Blood Vessel Mimic (BVM) Lab, at Cal Poly, there exists a constant demand for innovation and the expansion of polymer types and electrospinning capabilities for its BVM model. Along these lines, the BVM Lab has recently acquired two new electrospinning systems: the Spinbox, a commercially graded electrospinning system, and the Learn-By-Doing system, which was part of a recently completed thesis conducted by Jason Provol. Additionally, recently published literature has demonstrated polyvinyl alcohol (PVA) as a viable option for …

Ti-6al-4v Β Phase Selective Dissolution: In Vitro Mechanism And Prediction, Michael A Kurtz

All Dissertations

Retrieval studies document Ti-6Al-4V β phase dissolution within total hip replacement systems. A gap persists in our mechanistic understanding and existing standards fail to reproduce this damage. This thesis aims to (1) elucidate the Ti-6Al-4V selective dissolution mechanism as functions of solution chemistry, electrode potential and temperature; (2) investigate the effects of adverse electrochemical conditions on additively manufactured (AM) titanium alloys and (3) apply machine learning to predict the Ti-6Al-4V dissolution state. We hypothesized that (1) cathodic activation and inflammatory species (H₂O₂) would degrade the Ti-6Al-4V oxide, promoting dissolution; (2) AM Ti-6Al-4V selective dissolution would occur …

Reactive Chemistries For Protein Labeling, Degradation, And Stimuli Responsive Delivery, Myrat Kurbanov

Doctoral Dissertations

Reactive chemistries for protein chemical modification play an instrumental role in chemical biology, proteomics, and therapeutics. Depending on the application, the selectivity of these modifications can range from precise modification of an amino acid sequence by genetic manipulation of protein expression machinery to a stochastic modification of lysine residues on the protein surface. Ligand-Directed (LD) chemistry is one of the few methods for targeted modification of endogenous proteins without genetic engineering. However, current LD strategies are limited by stringent amino acid selectivity. To bridge this gap, this thesis focuses on the development of highly reactive LD Triggerable Michael Acceptors (LD-TMAcs) …

Electrostatic Effects On Lipid Bilayer Physicochemal Properties And Vesicle Adhesion, Oscar Zabala-Ferrera

Doctoral Dissertations

Lipids are an integral part of cells, being the principal component of the cell membrane, and contributing to the function and regulation of biological processes. Lipid nanoparticles mimicking a cell’s endosomes or exosomes are of particular interest within the pharmaceutical industry for their ability to deliver cargo such as RNA into target cells. The delivery process faces a multitude of challenges, so a rational design approach for vesicles that considers a lipid’s physicochemical contribution to the membrane is desired. To that end, this thesis explores the creation of large area biomembranes along with the development of electromechanical and optical characterization …

Nanocellulose Based Foams For Low-Cost Disposable Medical Applications, Dominic Kugell

Electronic Theses and Dissertations

Polyurethane foams have been a staple material for their use in medical positioners, such as post-surgery elevation pillows as well as specific tailored positioners for their use during surgery. Polyurethane foams are preferred because of their lower cost compared to other petroleum derived foams, their versatility, and suitable mechanical properties. However, the environmental impact, including both cost and perception, of these foams is immense. Therefore, alternatives are being explored with biopolymers emerging as a promising class of materials. Cellulose is one such polymer that has recently demonstrated desirable properties. In this study, cellulose nanofibrils (CNF), a household foaming agent, and …

In Vitro And In Vivo Diabetic Models For Assessment Of Tissue Engineered Vascular Grafts, Juan Carlos Carrillo Garcia

All Dissertations

Diabetes has become one of the leading causes of lower-limb loss worldwide. Every 30 seconds, a person loses a limb due to diabetic-related vascular complications. About one-third of patients needing lower-limb bypass surgery have debilitated autologous vessels unsuitable for use, and no other good long-term options are available. These detrimental effects on the vasculature are caused mainly by the hyperglycemic and hyperlipidemic conditions derived from diabetes. Under these conditions, an increase in advanced glycation end products (AGEs) and reactive oxygen species leads to irreversible crosslinks of extracellular matrix proteins, accelerating vascular pathology through vascular stiffening, endothelial dysfunction, inflammation, atherosclerosis, fibrosis, …

Fungi In Flux | Designing Regenerative Materials And Products With Mycelium, Arvind Bhallamudi

Masters Theses

As the world grapples with the escalating crisis of climate threats and environmental degradation, this research delves into the synergistic potential of design and biology, developing safe and sustainable materials for applications in prototyping, furniture and interior design. Harnessing the power of a unique organism - fungi, the study proposes an accessible, efficient, and resilient material resource system. It utilizes local waste streams and mycelium (the vegetative part of fungi) to grow functional structures. An experimental and small-scale protocol is modeled by testing bio-fabrication and bio-printing methods. The composites' performance qualities and characteristics are evaluated through mechanical testing and a …

The Biological Activity Of Dual-Responsive Glycopolymers For Intracellular Codelivery Of Antigen And Lipophilic Adjuvant, Micaela Shields

Honors Theses

Subunit vaccines present themselves as an attractive alternative to traditional approaches to vaccines, which utilizes whole organisms to trigger an immune response. While these traditional approaches have proven themselves reliable within the history of vaccinations, they generally deliver subpar robust cellular-mediated immunity and pose many safety risks. Composed of proteins and /or peptides, subunit vaccines are safer and more precise alternatives to traditional approaches. However, the pharmacokinetic properties of the macromolecules that make up these vaccines hinder the subunit vaccine’s level of immunogenicity [d1] Examples of this hindrance include but are not limited to aggregation at the injection site and …

The Antler: The Design And Development Of An Independent Shower Support Stand For Those Living With Lower Extremity Limb Loss, Kylie Wright

Honors Theses

While we do not often think about it, taking a shower is a privilege. Standing in the hot water, cleaning off after a long day outdoors, and taking a moment to simply relax is an experience that most people in the U.S. have participated in. However, about 1.4 million Americans do not have this luxury3. Lower extremity amputees have long been advised to shower while seated for their safety. This population is unable to experience the simple independence that accompanies standing in the shower. Despite the growing rate of amputations each year, no products are currently available on the market …

Soil Respiration Measurements Reveal High Retention Of Organic Carbon From Corn Residue Derived High-Lignin Fermentation Byproduct Enabling Sustainable Lignocellulosic Biofuel Production, Michelle Sun Wang

Dartmouth College Master’s Theses

While 2G biofuel production can utilize non-edible, lignocellulosic feedstocks such as agricultural residues to produce liquid fuel, harvesting crop residues is unsustainable without careful management of the soil underneath. By harvesting a fraction of the crop residues left in the field after harvest, soil health can diminish and critically, the soil organic carbon (SOC) stored in agricultural fields can decrease. Currently, in the most popular 2G process models published, the issue of soil degradation remains unresolved with residue harvest strategies receiving considerable attention in the literature and other SOC management strategies receiving far less. Specifically, the strategy of returning the …

Polymeric Biomaterials Approaches For Engineering The In Vitro Cellular Microenvironment For Mscs, Mahsa Letter-Mahsa Haseli

Graduate Theses and Dissertations

Cell therapy is a technology that relies on replacing diseased or dysfunctional cells with healthy functioning ones. One of the cells used for such advanced therapies are stem cells, owing to their ability to differentiate into specific cells required for repairing damaged or defective tissues or cells. The majority of cell-based products are intended to transiently persist in the patient, secreting factors which then allow the patient’s body to heal; in these products, the cells are subsequently eliminated from the body. Furthermore, unique manufacturing platforms, in addition to novel commercialization strategies, will be required to create a successful, sustainable cell …

Study Of The Stability Of Heparin/Collagen Layer-By-Layer Coatings, Hector M. Apodaca Reyes

Chemical Engineering Undergraduate Honors Theses

Pairing heparin with collagen-based medical implants has opened a whole new area of research for enhancing the desired effect of current implants. In fact, heparin (HEP) and collagen (COL) layer-by-layer (LbL) coatings have shown impressive results in forming polyelectrolyte multilayers. It has been already seen on skin grafts, nerve guide conduits (NGCs), and drug delivery devices yielding promising results. Due to being a simple, cost-efficient, and versatile option to fabricate thin biomimetic films, this self-assembly technique is one of the most effective methods to immobilize extracellular matrix (collagen and heparin) onto medical devices and implants. Even though previous studies have …

Comparing Firocoxib And Meloxicam In The Application Of Microneedle Patch For Transdermal Drug Delivery, Ruohan Li

Chemical Engineering Undergraduate Honors Theses

This thesis compares the performance of meloxicam and firocoxib in the aspects of its physical characteristic, chemical compositions, and in-vitro performances for transdermal pain management microneedle patches on farm animals. The microneedle patches are composed of polyvinyl alcohol (PVA), type I collagen (COL), and chitosan (CHI) as base material that carries NSAIDs to achieve therapeutic purposes. Scanning electron microscopy (SEM) was utilized to observe the morphological and physical characteristics of the microneedle patches. Both meloxicam and firocoxib microneedle patches were successfully prepared using the methodology, with organized microneedle distribution and sizing. And Fourier transform infrared spectroscopy (FTIR) confirmed the chemical …

Development Of A Cell-Based Regenerative Strategy To Modulate Angiogenesis And Inflammation In Ischemic Muscle, Fiona E. Serack

Electronic Thesis and Dissertation Repository

The delivery of human adipose-derived stromal cells (hASCs) to ischemic tissues represents a promising strategy to promote vascular regeneration for patients with critical limb ischemia (CLI). This thesis focused on the evaluation of hydrogels to enhance the retention and pro-angiogenic capacity of hASCs following delivery in vivo. Additionally, priming strategies to augment the paracrine function of hASCs were developed and assessed.

Recognizing the importance of endogenous macrophages in the pro-regenerative function of hASCs, delivery using a previously-developed hydrogel system, composed of peptide-functionalized methacrylated glycol chitosan (MGC-RGD) and a copolymer of poly(ethylene glycol) and poly(trimethylene carbonate) (PEG(PTMC-A)₂), was …

3-Dimensional Muscle Constructs: Using Hydrogels In Order To Model The Effects Of Exercise In Disease Conditions, Mark Mchargue

Theses and Dissertations--Biomedical Engineering

Currently, there is no standard in vitro model for studying the effects of mechanical stimulation on muscle in type II diabetes. Existing models primarily utilize electrical stimulation, which does not fully recapitulate the effects of exercise. In this thesis, we create a standardized in vitro model of murine muscle that can recapitulate the benefits seen in exercise when mechanically stimulated. Moreover, we show that a type II diabetes environment has similar effects on the muscle in vitro as well as in vivo.

Advanced Microstructural Characterization Of Functionally Graded Dental Ceramic Material For Materials-Informed Finishing, Angani Vigneswaran

Theses and Dissertations--Manufacturing Systems Engineering

Yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) has gained popularity as the choice of material for dental prosthetics. Ivoclar Vivadent’s IPS e.max ZirCAD Prime dental ceramic incorporates a unique gradient technology that varies the yttria content over the thickness of the material. The top layer is composed of 5Y-TZP which is desired for its optical properties while the bottom layer is composed of a much stronger 3Y-TZP. In between the two layers, 5Y-TZP and 3Y-TZP are mixed to form a transition layer. Varying the amount of yttria allows for more esthetically pleasing translucency in the visible areas of the restoration without compromising …

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 …

An Experimentally Validated Computational Model For The Degradation And Fracture Of Magnesium-Based Implants In A Chemically Corrosive Environment, Mark M. Ousdigian

Dissertations, Master's Theses and Master's Reports

In the orthopedic and cardiovascular fields there is a growing interest for biodegradable implants, which can be naturally degraded in the body environment over time so that no extraction surgery is required. These implants must be designed to maintain their strength until the fracture has healed in the body, which could be influenced by many factors such as -the patient’s age, activities, body weight, pre-existing conditions etc. Hence, an ideal implant design should be done on a patient-by-patient basis. In the present work, a computational model is developed to predict the degradation and fracture of magnesium-based implants in a stress-coupled …

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

Electronic Theses and 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 …

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 …

An Integrated Electronic-Skin Patch For Real-Time And Continuous Monitoring Of A Panel Of Biomarkers Combined With Drug Delivery, Tanzila Noushin

Electrical Engineering Theses

Inflammatory biomarkers present in the human body play a vital role in medical field by guiding the clinician in decision-making for many diseases. The levels of these inflammatory biomarkers are associated with the severity and progress of several diseases. Researchers have found that increasing severity of many diseases such as cardiovascular disease, after surgery infection, and adverse clinical outcomes due to infectious diseases, results in the elevation of the level of inflammatory biomarkers in human sweat. Furthermore, the inflammatory cytokines indicate the pathophysiology and prognosis of critically ill SARS‑CoV‑2 patients. In this thesis work, different sensors have been developed for …

Iron Nanoparticles For Magnetic Imaging Applications, Aleia Williams

Masters Theses

Extensive research on iron oxide nanoparticles for various applications including nanomedicine, energy applications, environmental remediation, and magnetic imaging have previously been performed. Many are currently FDA approved as magnetic resonance imaging contrast agents and tracers for magnetic particle imaging applications. Magnetic properties of such materials are crucial to obtain good contrast and resolution. However, studies have shown the magnetic properties of iron oxide nanoparticles are less in comparison to those found in pure iron nanoparticle.

This research involves the synthesis and characterization of iron nanoparticles for applications in magnetic resonance imaging contrast agents, magnetic particle imaging tracers, and therapeutic agents …

Development Of Enzyme-Responsive Polymersomes As A Drug Delivery System For Gm1 Gangliosidosis, Bipin Chakravarthy Paruchuri

All Dissertations

GM1 gangliosidosis is a lysosomal storage disorder caused by deficiency of β-galactosidase (βgal) and subsequent accumulation of GM1 ganglioside in lysosomes. The rare nature of this disorder presents challenges with prognosis and treatment. Enzyme replacement therapy (ERT) can effectively treat systemic deficiencies, but the intravenously administered enzyme cannot cross the blood-brain barrier (BBB) to treat the central nervous system. A delivery system to encapsulate and deliver the enzyme can facilitate enzyme transport across the BBB with suitable surface modifications. One of the pathological aspects of GM1-affected cells is the upregulation of the lysosomal enzyme hexosaminidase A (HexA). In this dissertation, …

Optimized 3d-Printing Of Carbon Fiber-Reinforced Polyether-Ether-Ketone (Cfr-Peek) For Use In Overmolded Lattice Composite, Ryan C. Ogle

Masters Theses

Current orthopedic implants are overwhelmingly composed from metallic materials. These implants show superior mechanical properties, but this can additionally result in stress shielding due to a modulus mismatch between the bone tissue and implanted device. Polymeric implants reduce this stress shielding effect but have much lower mechanical properties, limiting their use. Polylactic acid (PLA) is a widely used biodegradable thermoplastic polymer, however, its use has been limited by the polymer’s mechanical properties and rapid loss of strength during degradation in vivo. Polyether-ether-ketone (PEEK) is another common biocompatible polymer , with chemical and mechanical properties which make it a popular alternative …

Highly Adherent Antimicrobial Coatings For Orthopedic Implants, Mikhail Bredikhin

All Dissertations

Fracture-related infections (FRIs) are the most devasting sort of complications associated with fracture fixation devices, as they lead to patients’ morbidity, prolonged hospitalization, amputations, and even death.External fixators additionally suffer from pin site infections (PSIs), which initiate at the skin entry points of the skin-metallic pin interface present in the external fixation of the damaged bones, often causing deep tissue infection and osteomyelitis. Small percutaneous pins, commonly known as Kirschner wires (K-wires), are used to treat complex fractures and deformities.They are drilled inside the diseased bone for the healing period and are left protruding outside the skin for fixation adjustments …

Material Characterization And Comparison Of Sol-Gel Deposited And Rf Magnetron Deposited Lead Zirconate Titanate Thin Films, Katherine Lynne Miles

Mechanical Engineering ETDs

Lead zirconate titanate (PZT) has been a material of interest for sensor, actuator, and transducer applications in microelectromechanical systems (MEMS). This is due to their favorable piezoelectric, pyroelectric and ferroelectric properties. While various methods are available to deposit PZT thin films, radio frequency (RF) magnetron sputtering was selected to provide high quality PZT films with the added capability of batch processing. These sputter deposited PZT films were characterized to determine their internal film stress, Young’s modulus, composition, and structure. After characterization, the sputtered PZT samples were poled using corona poling and direct poling methods. As a means of comparison, commercially …

Frontiers In The Self-Assembly Of Charged Macromolecules, Khatcher O. Margossian

Doctoral Dissertations

The self-assembly of charged macromolecules forms the basis of all life on earth. From the synthesis and replication of nucleic acids, to the association of DNA to chromatin, to the targeting of RNA to various cellular compartments, to the astonishingly consistent folding of proteins, all life depends on the physics of the organization and dynamics of charged polymers. In this dissertation, I address several of the newest challenges in the assembly of these types of materials. First, I describe the exciting new physics of the complexation between polyzwitterions and polyelectrolytes. These materials open new questions and possibilities within the context …