Biomaterials Commons^™

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, …

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 …

Scaffold-Free Development Of Multicellular Tumor Spheroids With Spatial Characterization Of Structure And Metabolic Radial Profiles, Shelby N. Bess, Gaven K. Smart, Matthew J. Igoe, Timothy J. Muldoon

Biomedical Engineering Faculty Publications and Presentations

Purpose

In vitro assays are essential for studying cellular biology, but traditional monolayer cultures fail to replicate the complex three-dimensional (3D) interactions of cells in living organisms. 3D culture systems offer a more accurate reflection of the cellular microenvironment. However, 3D cultures require robust and unique methods of characterization.

Methods

The goal of this study was to create a 3D spheroid model using cancer cells and macrophages, and to demonstrate a custom image analysis program to assess structural and metabolic changes across spheroid microregions.

Results

Structural characterization shows that cells at the necrotic core show high normalized fluorescence intensities of …

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

Chemical Engineering Undergraduate Honors Theses

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

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 …

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 …

Transcriptome Profiling Of A Synergistic Volumetric Muscle Loss Repair Strategy, Kevin Roberts, John Taehwan Kim, Jacob Schluns, Grady Dunlap, Jamie Hestekin, Jeffery Wolchok

Biomedical Engineering Faculty Publications and Presentations

Volumetric muscle loss overwhelms skeletal muscle’s ordinarily capable regenerative machinery, resulting in severe functional deficits that have defied clinical repair strategies. In this manuscript we pair the early in vivo functional response induced by differing volumetric muscle loss tissue engineering repair strategies that are broadly representative of those explored by the field (scaffold alone, cells alone, or scaffold + cells) to the transcriptomic response induced by each intervention. We demonstrate that an implant strategy comprising allogeneic decellularized skeletal muscle scaffolds seeded with autologous minced muscle cellular paste (scaffold + cells) mediates a pattern of increased expression for several genes known …

Fabrication And Non-Covalent Functionalization And Characterization Of Graphene-Based Devices On Novel Substrate Cadmium Trithiophosphate (Iv) — Cdps, Abayomi Omotola Omolewu

Graduate Theses and Dissertations

With graphene at the center of several application areas such as sensing, circuits, high-frequency devices for communication systems, etc., it is crucial to understand how the intrinsic properties of devices made from graphene and other materials like platinum and palladium nanoparticles affect the performance of such devices for the specific application area. Many graphene-based devices for different application areas have focused mainly on the material composition of the graphene-based devices and how it affects performance parameters for the specific application. However, it would be insightful to understand how the intrinsic electrical properties of the graphene devices for different applications affect …

Performance And Fouling During Bioreactor Harvesting, Da Zhang

Graduate Theses and Dissertations

Tangential flow filtration has many advantages for bioreactor harvesting as the permeate could be introduced directly to the subsequent capture step, the process is easy to scale up, and fouling of the filter is limited by the cross flow. However, membrane fouling has limited its widespread use. This is particularly problematic given the high cell densities encountered today. Here a reverse asymmetric commercial membrane, BioOptimal™ MF-SL (Asahi Kasei), where the more open surface faces the feed stream, and the tighter barrier layer faces the permeate stream, has been investigated for bioreactor harvesting. The open surface contains pores up to 40 …

Surface Laser Texturing Of Cocrmo Alloys, Gabriel Dharwadker

Biomedical Engineering Undergraduate Honors Theses

Artificial orthopedic implants such as hip joints suffer from excessive wear due to excess friction between the polyethylene and cobalt-chromium-molybdenum surfaces of the device. This increase in friction causes a fraction of them to give out within ten years. Therefore, to minimize the probability of this happening, recent research has been conducted regarding laser surface texturing of the cobalt-chromium-molybdenum alloy components of artificial joints. These surface textures serve to mimic the native lubrication mechanisms of cartilage in natural joints, which, in a natural joint, lowers the friction. However, the production of these laser surface textures is still a field of …

The Interaction Of Angiotensin I And Ii On Calcified Aortic Valve Cells, Fah Sysavanh

Biomedical Engineering Undergraduate Honors Theses

Cardiovascular diseases affect the older population with limited treatments available. Aortic valve stenosis is a cardiovascular disease in which the aortic valve narrows, causing blood flow constriction and calcification.¹ The only treatment is to replace the valve, which can be costly and lead to other health complications.

The renin-angiotensin system (RAS) is a pathway that helps with maintaining cardiovascular homeostasis. Angiotensin I (ANGI) and II (ANGII) are hormones in the RAS that cause an increase in inflammation, stress, and blood pressure by binding to the Angiotensin Type 1 Receptor (AT1R).¹ Gelatin-based valve thin film (vTF) platforms were fabricated to investigate …

Alternative Fixation Of Venous Valves For Bioprosthetic Applications, Makenzie Kapales

Biomedical Engineering Undergraduate Honors Theses

Venous valve failure allows for the retrograde, or backward, flow of blood into the lower extremities, which leads to Chronic Venous Insufficiency (CVI). CVI infringes upon quality of life through ulceration and can result in death due to Deep Vein Thrombosis (DVT), or blood clots, causing pulmonary embolism. A successful treatment of CVI restores valve function and prevents retrograde blood flow; however, current bioprosthetic venous valves exhibit low patency and high calcification. To improve upon bioprosthetic venous valves and CVI treatment, the University of Arkansas’s Cardiovascular Biomechanics Lab conducts studies with the purpose of comparing the properties and performance of …

Hydrogel Drug Delivery Platform Integrity And Utilization Analysis, Joshua Carson Adams

Biomedical Engineering Undergraduate Honors Theses

Traumatic Spinal Cord Injury (SCI) generally results in permanent sensorimotor dysfunction. This is due to failed axonal regeneration at the site of injury. Recent studies have highlighted the use of stem-cell based therapies embedded in hydrogel to treat SCI. Embedding cell therapies in hydrogel provides a platform that increases the survival of both integrated grafted cells and stem cells/stem cell progeny. There are a variety of drug delivery agents for treating SCI such as neuro-regenerative cells and Schwann cells, however, single agents are not promising for functional regeneration. We propose a combinatorial approach using sciatic nerve (SN) extracellular matrix (ECM), …

Drug-Facilitated Sexual Assault At The University Of Arkansas, Barrett Weidman

Chemical Engineering Undergraduate Honors Theses

This work was written to fulfill two main purposes. First, to help survivors of Drug-Facilitated Sexual Assault (DFSA) process their experience by compiling the toxicological, pharmacological, and distribution of the three most used date-rape drugs. Second, to gauge the knowledge and interest of University of Arkansas students regarding drug impairments, sexual assault education, and bystander intervention training. A survey was conducted for the latter and revealed that 91.6% of students believe the University’s existing sexual assault prevention education and bystander intervention training have room for improvement. Also, 37.1% of students who have received this education report that the programming does …

Exploring The Effects Of Varied Land Use On Elemental Concentrations Within Streams, Logan Jennings

Biological and Agricultural Engineering Undergraduate Honors Theses

It is well documented that human activity influences the chemistry of surrounding waters. As such, it is possible that there is a link between land use within a watershed and the chemical composition of the stream. The objectives of this study are to determine if varied land use does affect the concentrations of macronutrients and trace elements present in the streams of Northwest Arkansas, and if so, to determine what extent urban and agricultural development are responsible for these changes. Water samples were collected across 19 streams in the Northwest Arkansas region between January and March of 2022. Water samples …

Synthesis And Performance Testing Of Ecm Fiber Scaffolds, Cassandra Reed

Graduate Theses and Dissertations

The progression of regenerative medicine has advanced the treatment of multiple illnesses and injuries throughout the years. A good example of the benefits of this research is the work that has gone into volumetric muscle loss (VML), where more than 20% of the muscle is loss. Skeletal muscle makes up 40% of the human body so a loss of that size greatly diminishes the strength, the flexibility, physiology, and quality of life of the injured individual. For that reason, various techniques are used to counteract the loss of structure and innate cellular signaling in order to circumvent that from happening. …

Evaluating Cellular Response Of Different Valve Interstitial Cell (Vic) Phenotypes To Angiotensin I, Smit Patel

Biomedical Engineering Undergraduate Honors Theses

Calcific Aortic Valve Disease (CAVD), one of the leading causes of death in the United States, is characterized by diminished functioning and limited movement of the aortic valve (AV) due to increased thickening, disorganized extracellular matrix elastin fibers, increased collagen content, and abnormal deposition and formation of calcium nodules on the AV [1, 2]. There are two types of CAVD: i) Aortic valve sclerosis (AVS), in which patients suffer from tissue hardening, fibrosis, and early calcification, and ii) calcific aortic stenosis (CAS), representative by excessive calcification on the AV and reduced AV opening, are the two main forms of CAVD …

Developing Aligned Nerve Scaffolds In A 3d Type-I Collagen Gel, Gabriel David

Biomedical Engineering Undergraduate Honors Theses

Despite significant progress in the field of peripheral nerve repair, clinical success is still limited, leaving millions to suffer from peripheral neuropathy with billions spent every year for treatment. Nerve repair methods that are capable of maximizing the regenerative properties of peripheral nerves are greatly desired in the field of medical science. This research aims to fill the gap between modern methods and the future of nerve repair by creating type-I collagen scaffolds with aligned degradation pores that will assist and nurture nerves growing through them. This is achieved by incorporating adipose stem cells into type-I collagen hydrogels and aligning …

Promotion Of Human Schwann Cell Proliferation Using Heparin/Collagen Coated Nerve Conduits, John Magness

Chemical Engineering Undergraduate Honors Theses

Often in the aftermath of an injury or surgery, the sense of touch and muscle control is lost in the affected area as nerves are damaged or severed and fail to grow back completely. The regeneration of the nerve cells can be promoted by treating the nerves with nerve conduits. Nerve conduits are hollow cylinders of bio-compatible materials that can be surgically implanted to the disconnected nerve to promote and direct the growth of nerves. The objectives of this research are to investigate the ability of nerve conduits treated with layer-by-layer coatings to promote the growth of Schwann cells, to …

Peptoid-Functionalized Gold Nanoparticles For Zika Virus Envelope Protein Detection, Meagan Olsen

Chemical Engineering Undergraduate Honors Theses

Detection and identification of viral pathogens is essential in providing effective and rapid medical treatment. Well-established detection methods can be expensive, slow, and sometimes unable to provide the needed sensitivity and specificity. The Zika virus is one clinically relevant pathogen that cannot be easily identified due to cross-reactivity with other viruses from the same family. Electrochemical sensors enhanced with peptoid-functionalized gold nanoparticles (AuNPs) are an alternative to traditional techniques that offers rapid, accurate, label-free pathogen detection for point-of-care diagnostics. To this end, a peptoid capable of binding to the Zika virus envelope protein was developed and its binding affinity for …

Evaluating The Effects Of Wood Source On The Physicochemical Properties Of Crosslinked Cellulose Nanocrystals, Helena Tchoungang Nkeumen

Graduate Theses and Dissertations

Cellulose is an abundant and naturally occurring biopolymer that has been used by humans for food, shelter, and clothing for about two centuries now. Highly crystalline nanoparticles derived from cellulose, called cellulose nanocrystals (CNCs), show great potential to meet the rising need for sustainable and nontoxic materials for biomedical applications. However, multiple biomedical applications of CNCs, such as those involving their use in tissue engineering scaffolds, require CNC-based structures to be stable in aqueous environments, a property that native CNCs do not possess due to their inherent hydrophilicity. Chemical crosslinking of CNCs addresses this issue by providing aqueous stability to …

Design And Control Of A Peristaltic Pump To Simulate Left Atrial Pressure In A Conductive Silicone Model, Jeremy Collins

Mechanical Engineering Undergraduate Honors Theses

According to the CDC, atrial fibrillation is responsible for more than 454,000 hospitalizations and approximately 158,000 deaths per year. A common treatment for atrial fibrillation is catheter ablation, a process in which a long flexible tube is guided through the femoral artery and to the source of arrhythmia in the heart, where it measures the electrical potential at various locations and converts problematic heart tissue to scar tissue via ablation. This paper details the design and control of a low-cost ($400) peristaltic pump system using repetitive control to replicate blood pressure in the left atrium in a conductive silicone model …

Peptoid-Based Microsphere Coatings For Biomaterial Applications, Jesse Leland Roberts

Graduate Theses and Dissertations

Peptoids are peptidomimetic oligomers that predominantly harness similarities to peptides for biomimetic functionality. The incorporation of chiral, aromatic side chains in the peptoid sequence allows for the formation of distinct secondary structures and self-assembly into supramolecular assemblies, including microspheres. Peptoid microspheres can be coated onto substrates for potential use in biosensor technologies, tissue engineering platforms, and drug-delivery systems. They have the potential for use in biomedical applications due to their resistance to proteolytic degradation and low immunogenicity. This dissertation focuses on the physical characteristics and robustness of the peptoid microsphere coatings in various physiological conditions, along with their ability to …

The Effects Of Solution Condition On Virus Filtration Performance, Fnu Namila

Graduate Theses and Dissertations

Virus filtration is an integral part of the downstream purification of mammalian cell culture-derived biotherapeutics to assure the viral safety of the products. Virus filtration membranes remove viruses based on a size-exclusion mechanism. Commercial parvovirus filers possess unique membrane structure and are designed to remove smaller non-enveloped parvoviruses with size 18-26 nm. However, some filters face issues, such as pre-mature fouling, the decline of filtrate flux, and reduction in virus retention. This doctoral dissertation focused on identifying the factors that influence the filtrate flux and the virus retention capability of commercial virus filters. The effects of solution pH and ionic …

Analysis Of Blood Purification Studies On Oxone Mediated Tempo-Oxidized Nano Cellulose Mixed-Matrix Membranes, Tony Roller

Biomedical Engineering Undergraduate Honors Theses

End-stage renal disease (ESRD) is currently the ninth leading cause of death in the United States, and of the 661,00 Americans diagnosed with ESRD, approximately 468,800 were on hemodialysis in 2016. Hemodialysis refers to a technique where a machine combined with a membrane, often referred to as an artificial kidney, is used to clean blood by removing any waste such as urea, potassium, and other smaller waste products while preserving the concentrations and integrity of cells and proteins in the blood. It has been shown in artificial blood studies that cellulose nanomaterials, like TEMPO/Oxidized cellulose nanoparticles (TOCNs), can be integrated …

Characterization Of Oxone Mediated Tempo-Oxidized Nano Cellulose Mixed-Matrix Membranes During Ultrafiltration And Hemodialysis, Kristyn Robling

Biomedical Engineering Undergraduate Honors Theses

The ninth leading cause of death in the United States is kidney disease, and hemodialysis is the process most commonly prescribed for treatment. It utilizes a selectively permeable membrane filter to remove toxins such as urea from the blood and retain necessary protein levels. However, traditional filters, such as cellulose triacetate, used during dialysis can be inefficient in terms of separation performance and reduction of fouling. Recent exploration of nanoparticles has resulted in the creation of Oxone Mediated TEMPO-Oxidized Nano Cellulose which has properties that are believed to increase hydrophilicity, increase tensile capacity, decrease membrane resistance and lower fouling, making …

Modified Stent Design For A Coronary Bifurcation Lesion, Abigail Nowell

Biological Sciences Undergraduate Honors Theses

Currently, 18.2 million adults aged 20 and older are diagnosed with Coronary Artery Disease (CAD) (Benjamin et al., 2019). Stenosis is the most common intervention. However, when a patient has a bifurcated artery, treatment becomes more difficult and is often unsuccessful. This project created a new stent and balloon complex that was tested in vitro using a gel phantom artery model. Two separate prototypes have been created and tested so far, with improvements made upon each. Testing is still underway with Prototype 2.