Biomaterials Commons^™

Laponite Nanosilicate As A Platform For Antigen–Adjuvant Co-Delivery In Vaccination, Haoyu Qi

McKelvey School of Engineering Graduate Student Theses & Dissertations

Nanosilicates are two-dimensional, charged nanomaterials with tunable surface chemistry that enable electrostatic interactions with proteins and nucleic acids. These properties make Laponite nanosilicate a promising platform for vaccine delivery, where coordinated antigen–adjuvant presentation and lymph node delivery are important for shaping immune responses. This thesis investigated nanosilicates as scaffolds for lysozyme-based antigen delivery and co-delivery with CpG.

The preparation method reduced the apparent size of the NS–Lys–CpG complex at pH 10, although neutralization to pH 7 promoted larger aggregate formation. In vivo IVIS imaging after footpad injection showed persistent Cy7-associated fluorescence at the injection site for up to three weeks …

Evaluation Of Alternative Solvents For Electrospinning Occluded Scaffolds To Model Intracranial Atherosclerotic Disease In Blood Vessel Mimics, Olivia D. Rankin

Master's Theses

Intracranial atherosclerotic disease (ICAD) is characterized by a buildup of fatty plaque within the walls of arteries supplying the brain, resulting in vessel narrowing, restricted blood flow, and increased risk of ischemic stroke. While various treatments exist for ICAD, most are accompanied by high recurrent stroke rates and other adverse events, highlighting the need for further investigation and models for pre-clinical testing. Tissue engineered Blood Vessel Mimics (BVMs), consisting of a polymer scaffold sodded with human vascular cells, serve as physiologically relevant in vitro models for vascular device testing. This thesis focused on the application of alternative solvents to a …

Pet Mobility Project, John Shelby, Lily-Rose Jolie Bacon, Andrea Yasmine Reyes

Biomedical Engineering

The Pet Mobility Project, sponsored by Terri Smith and Jasper Jackson, is an initiative aimed at providing a custom mobility aid to a pet in the San Luis Obispo community. Amber Rappozo’s young German Shepherd, LeDoux, was selected as the project’s recipient. LeDoux suffers from hindleg weakness and, as a result, has limited mobility. This document provides a comprehensive overview of the Pet Mobility Project, detailing the motivation, background, and design approach behind the development of a LeDoux’s custom mobility aid.

Strengthening Kidney Dialysis One Membrane At A Time: Enhancing Tempo-Oxidized Nanocellulose And Ionic Liquid Membrane Strength Through The Variation Of Cosolvents, Bailey M. Butler

Chemical Engineering Undergraduate Honors Theses

Chronic kidney disease occurs when the kidneys lose the ability to effectively filter the blood, which causes waste build up. End-stage kidney disease (ESKD) is the most severe case of kidney disease and requires either dialysis or a kidney transplant. Hemodialysis, the most common form of dialysis, is an extremely time-intensive and physically burdensome process that is currently limited by membrane performance. The polysulfone (PSf) membranes that are widely used for dialysis today have many limitations, including fouling, toxin rejection, and essential protein loss. Recently, new membranes made from TEMPO-Oxidized nanocellulose dissolved in 1-ethyl-3-methylimidazolium acetate (EMIM-Ac) have shown promising characteristics, …

Volumetric Wear Analysis Of Polyethylene Orthopedic Liners Using Point Clouds, Gabriel Landi

Dartmouth College Master’s Theses

In vivo wear of ultra-high molecular weight polyethylene (UHMWPE) orthopedic bearings represents a major problem in shoulder and knee arthroplasty, with significant amounts of devices failing due to the complication itself, and even more due to associated reasons for retrieval, including aseptic loosening. However, quantification of UHMWPE wear has largely been limited to linear and in vitro volumetric analyses, obscuring the understanding of the amount of clinically relevant material loss. This study proposes new methods to measure articular, rim, and backside surfaces of retrieved shoulder and knee UHMWPE liners, centered around the coordinate measuring machine (CMM)-based collection of high density …

Stentrx, Emma Barna, Minuthi Cooray, Bruce Newlands, Joseph A. Sabetta

Williams Honors College, Honors Research Projects

This project aims to develop a biodegradable, drug-eluting biliary stent for the treatment of biliary cancers. Current metal stents that restore bile flow bit are non-degradable, prone to migration, and unable to deliver drugs locally. The proposed stent will be biocompatible, biodegradable, and capable of controlled drug release to both maintain bile flow and treat tumors. The end goal is to produce a functional prototype that can be deployed via a minimally invasive catheter and maintain bile duct patency for at least three months. The project is expected to be involved in the NEOMED Bench-to-Bedside competition and provisionally patented.

Generating Concentrated Ring Polymers Through Supercoiled And Open Circle Pdna Isoform Separation, Kelsey E. Hodsdon

Honors Theses and Capstones

DNA can serve as a model polymer due to its high uniformity compared to synthetic polymers. Plasmid DNA (pDNA) in particular offers a well-defined, low-dispersity model for studying topologically uniform systems of a cyclic nature. pDNA has unique isoforms known as open circle (OC) and supercoiled (SC). Using fast protein liquid chromatography (FPLC), specifically anion exchange chromatography (AEX), these OC and SC isoforms can be separated in order to access their unique material properties. Our lab was able to yield the pure SC isoform. However, OC isoform separation has been more challenging. Various difficulties arose during this process, including imaging …

Engineering Plga Nanoparticle Size To Modulate Immune Responses After Spinal Cord Injury, Daniel J. Kolpek

University of Kentucky Doctoral Dissertations

Spinal cord injury is a severe and debilitating condition that often results in lifelong complications, including paralysis. Many of these chronic outcomes are driven by a sustained inflammatory response at the injury site, which limits tissue regeneration and functional recovery. As a result, therapeutic strategies that modulate this immune response have gained significant interest. Polymer based nanoparticle therapies have emerged as a promising approach due to their ability to interact with and influence immune cell behavior. Importantly, the physicochemical properties of nanoparticles can be precisely tuned to optimize these effects. Among these properties, size has been shown to influence key …

Development Of An Adhesive Emulsion Hydrogel For Soft Tissue Reconstruction, David J. Alpert

Dissertations and Theses

Soft tissue filling materials are most commonly associated with various aesthetic, cosmetic procedures, primarily using lightly cross-linked hyaluronic acid to fill wrinkles and give facial features a more youthful appearance. These natural materials are biocompatible but degrade over time while more persistent synthetic fillers may provoke a chronic inflammatory response. Migration from the injection site is also a key factor as this may not only render the implant non- functional but necessitate further procedures for removal of the foreign material. Such concerns are more pronounced for soft tissue reconstruction procedures (e.g., to treat congenital defects or traumatic injuries), which require …

Synthesis And Characterization Of Glass-Ceramic Nanoparticles And Nanobubbles For Integration Into Bone Regenerative Biomaterials, Sun Latt

Honors Undergraduate Theses

Osteoporosis affects over 200 million individuals worldwide and is characterized by an imbalance between osteoclastic bone resorption and osteoblastic bone formation, leading to fragility fractures that significantly diminish quality of life. Current clinical bone cements, such as poly(methyl methacrylate), are limited by poor osseointegration, toxic monomers, and an inability to address the underlying pathophysiology of osteoporosis. This work presents the synthesis, characterization, and systematic in vitro evaluation of a sol-gel-derived, magnesium-incorporated glass-ceramic (GC) nanoparticle within the CaO-MgO-SiO₂ system for incorporation into a novel hydrogel bone cement and bioresorbable magnesium implants. XRD confirmed a biphasic amorphous-crystalline diopside composition, and TEM …

De Novo Protein Binding To Zinc Oxide Through Biomineralization Pathways, Jean-Mark A. Francis

Theses and Dissertations

De novo proteins are structurally distinct from proteins found in nature and thus capable of having their amino acid sequence modified to accomplish tasks such as increasing protein-nanoparticle binding without unfolding or decomposing. Zinc Oxide nanoparticles are functionally distinct from their bulk counterparts and are widely used as semiconductors in a variety of fields such as medicine and agriculture. With demand for these nanoparticles increasing, environmentally sustainable methods of Zinc Oxide nanoparticle synthesis are being investigated as an eco-friendly alternative to currently utilized but environmentally hazardous chemical and physical techniques. This research investigates the binding characteristics between Zinc Oxide nanoparticles …

Expansion Limits Of Meshed Split-Thickness Skin Grafts, Haomin Yu

McKelvey School of Engineering Graduate Student Theses & Dissertations

Split-thickness skin grafts are widely used to treat chronic wounds. Procedure design requires surgeons to predict how much a patch of the patient's own skin expands when it is meshed with rows of slits and stretched over a larger wound area. Accurate prediction of graft expansion remains a challenge, with current models overestimating the actual expansion, leading to suboptimal outcomes. Inspired by the principles of mechanical metamaterials, we developed a model that distinguishes between the kinematic rearrangement of structural elements and their stretching, providing a more accurate prediction of skin graft expansion. Our model was validated against extensive data …

2d-Nanosilicate Carriers For Sustained Delivery Of Vaccine Components, Chih Yun Liu

McKelvey School of Engineering Graduate Student Theses & Dissertations

Laponite® 2D Nanosilicates (NS) are disc-shaped platelets (~30 nm diameter, ~1 nm thick) with positively charged edges and negatively charged faces, capable of loading proteins, drugs, and nucleic acids via electrostatic interactions to form a house-of-cards gel that sequesters cargo. Here, we evaluated NS for sustained delivery of antigens and Toll-like receptor (TLR) agonists to extend germinal center duration and enhance antibody quality. The model antigen ovalbumin (OVA) was adsorbed onto NS at acidic pH in a ~1:1 ratio, with partial unfolding that remained stable at physiological pH. NS-OVA complexes were efficiently internalized by dendritic cells, with uptake driven primarily …

Degradation Of Cobalt Chrome Molybdenum Hip And Knee Implants In Vivo And In Vitro, Peter William Kurtz

All Dissertations

Cobalt Chrome Molybdenum (CoCrMo) remains a popular material choice for femoral condyles in total knee arthroplasty and for acetabular liners in dual mobility total hip designs. CoCrMo has been phased out of conventional THA designs due to its correlation with adverse effects such as ALTR and ALVAL. It is less understood if the mechanisms (i.e. abrasive wear to the surface of the implant) that release metal ions into the surrounding tissue occur at similar rates as seen in conventional THA. Additionally, it is unknown what effect the secondary damage modes such as electrocautery damage and adhesive wear have on these …

Crevice Corrosion Mechanisms Of Cocrmo Alloys In Orthopedic Implants: Retrieval Analysis, Nano-Tribocorrosion And Cellular Responses, Hwaran Lee

All Dissertations

Mechanically assisted corrosion and non-mechanically (chemically) driven corrosion in modular junctions of orthopedic implants using cobalt-chromium-molybdenum (CoCrMo) alloys remain clinical concerns and may contribute to implant failure. The underlying corrosion mechanisms are not yet fully understood, leaving a critical research gap. We hypothesized that corrosion in modular junctions may be driven by aggressive local environments, including fretting, metal ion release (cobalt ion, Co²⁺), low pH and reactive oxygen species (ROS). This dissertation aims to (1) analyze corrosion modes and potential causes in modular junctions; (2) identify chemically driven corrosion modes on CoCrMo alloys using simulated inflammatory modular taper …

Characterization Of Lactobacilli-Containing Catheter Segments Developed By Using Selective Laser Sintered Mold., Caden Maners

Master of Engineering Theses

Catheter-associated urinary tract infections (CAUTIs) are a major healthcare burden with current prevention strategies offering limited success. This study presents a novel, self-coating biomaterial approach using a silicone-based bioink embedded with thermally sensitive probiotic strains (L. crispatus, L. rhamnosus, and L. reuteri). Catheter segments were fabricated via bio-injection molding using 3D-printed CAD molds. These Lactobacilli, selected for their probiotic and antimicrobial potential, serve as a non- antibiotic strategy to reduce infection risk. These segments were evaluated for mechanical strength (Shore A hardness), thermal stability (TGA/DSC), porosity and bacterial presence (SEM), biofilm formation (crystal-violet assay), as well as mass retention in …

A Wearable-Based Approach To Spinal Posture Tracking And Assessment, Sydney Marie Sherman, Noah Jeffery

Biomedical Engineering: Graduate Reports and Projects

This paper describes the design, manufacturing, and testing of a novel spinal posture tracking wearable device with embedded sensors. Currently on the market, most of the spinal posture tracking devices only focus on one segment of the spine and therefore do not track the entirety of human posture. The objective for this project was to create a wearable device in the form of a “smart shirt” that offers insights into posture trends throughout the day by tracking the entire spine. To begin the project, multiple designs were developed for the sensor array and wearable materials. These concepts were compared against …

Novel Electrospinning Techniques For Fabricating Scaffolds To Model Intracranial Atherosclerotic Disease In Tissue Engineered Blood Vessel Mimics, Isaac "Squeaky" Buentipo

Master's Theses

Novel Electrospinning Techniques for Fabricating Scaffolds to Model Intracranial

Atherosclerotic Disease in Tissue Engineered Blood Vessel Mimics

Isaac “Squeaky” Buentipo

Dr. Kristen Cardinal’s Tissue Engineering Lab at California Polytechnic State University specializes in fabricating customized vascular models, known as Blood Vessel Mimics (BVMs), for medical device testing. BVMs are simplified in vitro vascular models designed to bridge the gap between bench testing and in vivo evaluation of intravascular medical devices. BVMs are produced by combining a polymer scaffold with human vascular cells. Through novel scaffold fabrication techniques, such as silicone injection molding, silicone dip casting and electrospinning, the capabilities of …

Opmed Seal: Engineering A Rapid-Response Biodegradable Device For Hemorrhage Control And Infection Prevention In Abdominal Trauma, Paula M. Cabrera, Wesley Stephen Murphy

Honors Theses

Abdominal gunshot wounds are amongst the deadliest injuries encountered in combat and remote emergency settings. For military medics and first responders, the challenge lies in controlling internal bleeding and preventing infection before patients can reach surgical care-often within a narrow window of time known as the “golden hour”. Currently available field treatments are either too slow, not designed for internal wounds, or fail to provide antimicrobial protection. To address this gap, our team developed OpMed Seal: a compact, dual-syringe delivery system that deploys a biodegradable, antibiotic-infused hydrogel directly into abdominal injuries. The system is designed for rapid hemorrhage control, localized …

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

Biomedical Engineering Undergraduate Honors Theses

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

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

Biomedical Engineering Undergraduate Honors Theses

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

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

Biological Sciences Undergraduate Honors Theses

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

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

Honors Theses

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

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

All Dissertations

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

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

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

Honors Theses

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

Development Of Rolipram Loaded Pgp Nanoparticles For Spinal Cord Injury Repair, Zhen Liao

All Dissertations

Spinal cord injury (SCI) leads to devastating neurological deficits due to primary mechanical damage and secondary injury mechanisms, including inflammation, oxidative stress, excitotoxicity, and inhibitory scarring, which collectively impede neural regeneration. One key aspect of SCI pathology is a significant reduction in cyclic adenosine monophosphate (cAMP) levels, primarily due to increased phosphodiesterase (PDE 4) activity. As a ubiquitous second messenger, cAMP regulates key signaling pathways, including protein kinase A (PKA) / cAMP response element-binding protein (CREB) and exchange protein activated by cAMP 2 (EPAC2). Therefore, restoring/increasing cAMP level is one of the major therapeutic strategies to reduce neurotrauma and restore …

Evervital Patch: The Design And Development Of A Continuous Cardiac Monitoring Device For Post-Operative, In-Hospital Patients, Abigail Moeller, Jonathan Seid

Honors Theses

In the United States, due to the increasing prevalence of cardiovascular disease, over 900,000 cardiac surgeries are performed annually, with projections exceeding 1.3 million by 2029. Many post-surgical patients require continuous in-hospital cardiac monitoring, which is typically conducted using electrocardiograms (EKGs). However, traditional EKG systems such as bedside cardiac monitors and cardiac telemetry monitors rely on wired leads that can easily tangle, degrade signal quality, and require frequent readjustments or replacements due to wire breakage, and for the patient, this can cause discomfort from prolonged use. To overcome these challenges, our company, CardioSync, aims to develop a wireless cardiac monitoring …

Comparison Of Milling Cutting Forces In Synthetic And Biological Cancellous Bone, Matthew Christopher Hartwell

Masters Theses

In many orthopedic and dental interventions, the cutting and removal of bone is necessary. Therefore, it is of the utmost importance that the tools used during these procedures are designed and tested with biological bone or a bone surrogate material that machines the same way as biological bone. To avoid the cost, hazard, and inconsistency of biological cadaveric bone or animal models, many biological engineering firms use bone surrogate material made of glass fiber filled epoxy and polyurethane foam. Although these materials may mimic the elongation of cortical and cancellous bone, respectively, the match of machinability of the bone is …

Explorations Of Dna-Single-Walled Carbon Nanotube Interactions To Develop Multiplexed Molecularly Specific Biosensors For Inflammation, Amelia K. Ryan

Dissertations and Theses

Inflammatory cytokines such as interleukin-6 (IL-6) and interleukin-12 (IL-12) are central regulators of immune signaling and key biomarkers of disease, yet existing assays for their detection remain slow, invasive, and lack multiplexing ability. This dissertation advances the development of single-walled carbon nanotube (SWCNT) optical nanosensors capable of real-time, multiplexed, and molecularly specific cytokine detection through innovative use of single-stranded DNA (ssDNA) interfaces.

First, an IL-6-specific DNA aptamer was employed as both a dispersing agent and recognition probe for SWCNT fluorescence sensing. Sequence modifications, including anchor domains, truncations, and thermally induced refolding, were systematically tested to optimize sensitivity and selectivity. The …

Enhancing The Mechanical Properties Of Sla 3d-Printed Bio-Resin From Linseed Oil Using Cellulose And Lignin Biopolymers, Chukwunonso A. Ikedionu

College of Graduate Studies: Theses & Dissertations

Abstract

This research explores the development of bio resin from linseed oil by the process of epoxidation and acrylation to produce acrylated epoxidized linseed oil (AELO). Lignin and cellulose biopolymers were added as reinforcement at varying weight fractions of 1 wt.%, 2.5 wt.%, and 5 wt.%, and their mechanical performance was compared against pure AELO. The formulations were printed using an Elegoo SLA 3D printer to create standardized test specimens like tensile bars, compression cylinders, and hardness blocks, which were all prepared according to the ASTM testing standard.

The results indicate that reinforcement effects depend on both filler type and …