Biomaterials Commons^™

Collapsible Silicone Tubes: An In Vitro Model For Tracheal Traction, Kevin D. Garman

Master's Theses (2009 -)

Obstructive sleep apnea (OSA) is characterized by recurrent episodes of airway collapse and airflow limitation during sleep. Fragmented sleep and reductions in blood oxygen saturation lead to several comorbidities, including hypertension, cardiovascular disease, and cerebrovascular disease. Longitudinal forces (tracheal traction) acting on the soft tissues surrounding the upper airway have been proposed to play a significant role in stabilizing the airway and preventing collapse. However, the relative contribution of longitudinal forces as compared to other factors that affect airway stability (airway geometry, tissue properties, muscle activity) remains unclear. This in-vitro study aimed to investigate to what extent longitudinal forces can …

Development Of Starch-Polyvinyl Alcohol (Pva) Biodegradable Film: Effect Of Cross-Linking Agent And Antimicrobials On Film Characteristics, Aniket Satish More, Chandani Sen, Madhusweta Das

Journal of Applied Packaging Research

To satisfy the need of developing eco-friendly flexible antimicrobial packaging film with minimum use of synthetic chemical ingredients, the present study examined the efficacy of citric acid (CA) as cross-linking agent and essential oils (EOs), viz., cinnamon essential oil (CEO) and oregano essential oil (OEO) as natural antimicrobials in corn starch-polyvinyl alcohol (CS-PVA) film. Compared to film prepared from filmogenic solution (FS) containing 75 kg CS+8.75 kg PVA+24.6 kg glycerol per m³ FS, film additionally containing CA at 0.07 kg/kg CS indicated 95% higher ultimate tensile strength (UTS) and 27% lower water vapor permeability (WVP). Film developed with incorporation …

Identifying And Reducing Variability, Improving Scaffold Morphology, And Investigating Alternative Materials For The Blood Vessel Mimic Lab Electrospinning Process, Evan M. Dowey

Master's Theses

The work of the Cal Poly Tissue Engineering Lab is primarily focused on the fabrication, characterization, and improvement of “Blood Vessel Mimics” (BVMs), tissue engineered constructs used to evaluate cellular response to vascular medical devices. Currently, cells are grown onto fibrous, porous tubes made using an in-house electrospinning process from PLGA, a biocompatible co-polymer. The adhesion and proliferation of cells in a BVM is reliant on the micro-scale structure of the PLGA scaffold, and as such it is of great importance for the electrospinning process to consistently produce scaffolds of similar morphologies. Additionally, it has been shown that cell proliferation …

Rice Hull Bioreactor For Recirculating Aquaculture, Marlon A. Greensword

LSU Doctoral Dissertations

The engineering of floating media biofilters has been optimized over the years. The backwashing process has made them more energy and water efficient. Likewise, moving bed bioreactors (MBBR) are gaining interest and popularity because they are relatively affordable to build. Yet, developing countries’ aquaculture production remains largely excluded from the advances made in recirculating aquaculture systems (RAS). This discrepancy is partially driven by the high costs of media such plastic beads and Kaldnes (KMT) media, commonly used in MBBR.

This dissertation evaluates the usability and profitability of rice hulls (RH), an abundant by-product in many developing nations, as a sinking …

How Strongly Do Oysters Stick?, Nicolás M. Morato, Andrés M. Tibabuzo, Jonathan J. Wilker

The Summer Undergraduate Research Fellowship (SURF) Symposium

Biological adhesives are a type of interfacial material that has incredible potential to generate new biomimetic compounds that can replace current strong, but toxic, adhesives. Therefore, a study of the chemical composition and mechanical properties of those bio-adhesives is necessary. However, in the case of oysters, despite known chemical characterization of the adult’s adhesive, there are almost no studies on its mechanical properties. Furthermore, there is no available information on the adhesive properties of spat (oysters in their larvae state). Herein, we present the first mechanical characterization of the spat adhesive, measuring its adhesion strength by hydrodynamic determination using a …

Study Of Iron Ion Transit Through Three-Fold Channel Of Ferritin Cage, Shah Alam Limon

Graduate Theses/Dissertations

Ferritin is an iron-storage globular protein with an ability to uptake, mineralize and release iron ions in a controllable manner. The globular hollow shell allows storage of mineralized iron, with several channels responsible for the transit of ions into the shell and out of it. Understanding of the detailed molecular functioning of ferritin is required for rational design of biomimetic conjugate nano-biosystems containing ferritin-like constituents. In this work, ferritin was investigated both numerically by all-atom molecular dynamics (MD) simulations, and experimentally by Raman spectroscopy. Molecular dynamic simulations of a model system comprising iron ions (Fe2+) and a ferritin trimer expressing …

A Wood-Powered Lawn Mower: Separating The Rules Of Thumb From Engineering Design, William White

Mahurin Honors College Capstone Experience/Thesis Projects

Biomass gasification, the thermal process of exracting combustible gasses from organic matter, is an established procedure that has been used for many years to provide fuel in various applications. It is a potential source of renewable fuel and has proven useful as a crisis energy source. This thesis investigates the primary engineering science principles involved in gasifier-engine system design. It arises from and supplements a WKU mechanical engineering senior project. The senior project has developed a wood gasification system designed to power a riding lawn mower. The thesis reiews theory-based design and separates it from informal hit and miss approaches—rule …

A Tunable, Three-Dimensional In Vitro Culture Model Of Growth Plate Cartilage Using Alginate Hydrogel Scaffolds, Alek G. Erickson, Taylor D. Laughlin, Sarah Romereim, Catherine Sargus-Patino, Angela K. Pannier, Andrew T. Dudley

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Defining the final size and geometry of engineered tissues through precise control of the scalar and vector components of tissue growth is a necessary benchmark for regenerative medicine, but it has proved to be a significant challenge for tissue engineers. The growth plate cartilage that promotes elongation of the long bones is a good model system for studying morphogenetic mechanisms because cartilage is composed of a single cell type, the chondrocyte; chondrocytes are readily maintained in culture; and growth trajectory is predominately in a single vector. In this cartilage, growth is generated via a differentiation program that is spatially and …

Ultrasonically Responsive Tissue Engineering Scaffolds For The Temporal Control Over Osteo-Inductive Growth Factor Delivery, Catherine Linh

Senior Honors Projects

In 2012, approximately 6.8 million people in the United States were diagnosed with orthopedic injuries or diseases. Over 500,000 people in the United States underwent bone grafting procedures, which cost 2.5 billion dollars per year and can result in complications. Polymer-based grafting scaffolds can facilitate 3D bone tissue growth in a localized, sustained manner. However, bone regeneration requires the orchestration of a sequence of events. Current scaffolds based on degradation and diffusion cannot provide sequential deliveries. We aimed to design a polymer scaffold that can release one payload diffusively at early time points, followed by ultrasonically triggered release of a …

Patient-Derived Hydrogel As A Sacrificial Matrix For Efficient Cell Loading, Shalmli U. Joshi

Honors Scholar Theses

The field of tissue engineering focuses on delivering patient-derived stem cells to the body through the use of degradable biomaterials, such as hydrogels, which are infused into engineered scaffolds. Hydrogels act as templates to support and guide cells towards the regeneration of new tissue. In this study, we introduce a completely intraoperative procedure for obtaining a fibrin hydrogel for tissue engineering applications. In the past, fibrin hydrogel has been commonly formed by combining fibrinogen protein with animal-derived thrombin. Instead, we have developed an automated, and therefore reproducible, protocol to isolate and form fibrin hydrogel without the use of animal-derived thrombin. …

Chitosan Nanoparticle Modifications For Improved Gene Delivery In An Oral Dna Vaccine Application, Austin Helmink

Honors Program: Senior Projects (Public)

Vaccines represent one of the most significant medical innovations of the 20^th century, resulting in the eradication or near eradication of a handful of deadly diseases. However, many infectious diseases remain resistant to effective vaccination, largely due to a lack full immune activation by traditional protein-based vaccines. A promising alternative vaccination strategy is the emerging development of DNA vaccines, which rely upon the delivery of exogenous genetic material to host cells encoding for a viral or bacterial antigen in order to induce a robust immune response by closely mimicking live infection. The delivery of genetic material requires a carrier …

Toxicity Evaluation Of Magnetic Hyperthermia Induced By Remote Actuation Of Magnetic Nanoparticles In 3d Micrometastasic Tumor Tissue Analogs For Triple Negative Breast Cancer, Nathanael A. Stocke, Pallavi Sethi, Amar Jyoti, Ryan Chan, Susanne M. Arnold, J. Zach Hilt, Meenakshi Upreti

Chemical and Materials Engineering Faculty Publications

Magnetic hyperthermia as a treatment modality is acquiring increased recognition for loco-regional therapy of primary and metastatic lung malignancies by pulmonary delivery of magnetic nanoparticles (MNP). The unique characteristic of magnetic nanoparticles to induce localized hyperthermia in the presence of an alternating magnetic field (AMF) allows for preferential killing of cells at the tumor site. In this study we demonstrate the effect of hyperthermia induced by low and high dose of MNP under the influence of an AMF using 3D tumor tissue analogs (TTA) representing the micrometastatic, perfusion independent stage of triple negative breast cancer (TNBC) that infiltrates the lungs. …

The Sub-Chronic Vascular Response To Water-Borne Embolic Coacervates., Joshua P. Jones, Monika Sima, Russell J. Stewart

Biomedical Engineering Western Regional Conference

Water-borne coacervates that solidify in response to decreasing ionic strength have been developed as an agent for small vessel transcatheter embolization. Here, the sub-chronic vascular response to these agents will be presented. Embolic coacervates demonstrated a benign foreign body response, which supported tissue ingrowth and stabilized vessel occlusion out to 28 days. As with other liquid embolics, occlusion is dependent upon mechanical obstruction of the vessel and native thrombus. Over time, the thrombus becomes more organized by fibroblasts. Continuation of the processes seen at 28 days will likely result in fibrous encapsulation of the embolic coacervate, further stabilizing the occlusion.

Differentiation And Containment Of Derived Pancreatic Beta Cells, Caden Duffy, Alonzo Cook Ph.D.

Biomedical Engineering Western Regional Conference

Currently, the only permanent cure for Type 1 Diabetes is a pancreatic or islet transplant. With the shortage of donors, we are progressing research towards alternative therapies by differentiating induced pluripotent stem cells into derived pancreatic β-cells that can be transplanted and used as treatment for Type 1 Diabetes. We are investigating methods to increase the yield of fully derived, insulin producing pancreatic β-cells and are additionally researching the use of hydrophilized expanded polytetrafluoroethylene for use in cell containment devices. These devices could offer a future alternative for islet transplantation in human patients.

Super-Hydrophobic And Anti-Microbial Surfaces Via Carbon Infiltrated-Carbon Nanotubes, Christian Dalon Esplin, Anton Bowden, Brian Jensen

Biomedical Engineering Western Regional Conference

No abstract provided.

Structural Mrsa Resistance Through Carbon-Infiltrated Carbon Nanotube Coating Of External Fixator Pins, Jaclyn Larsen, Stephanie Morco, Brian Jensen, Anton Bowden

Biomedical Engineering Western Regional Conference

No abstract provided.

Resorption Rate Of Bioresorbable Materials For Possible Use In Self-Expanding Stents, Jared R. Park, Jason Porter, Anton Bowden

Biomedical Engineering Western Regional Conference

This study investigates the mechanical behavior of various polymers after a period of degradation from exposure to a Saline Solution. The study found that PLA and PDLLA do not have significant degradation over a period of 2 months, while PLA has a sharp decrease in strength after 7 days.

Effect Of Multiple Confined Compression/Stress Relaxation Cycles On Cross-Linked Alginate Pore Size., Sindhu Kolar Venkat, Erik L. Risa, Bergren Antell, Maryam Mobed-Miremadi

Biomedical Engineering Western Regional Conference

No abstract provided.

Towards A Bioselective Surface For Treatment Of Sepsis In A Hemoperfusion Device, Karl F. Schilke, Ramya Raman, Bonan Yu, Erik Hahn, Jonathan Su

Biomedical Engineering Western Regional Conference

Sepsis is a dysregulated immune response to circulating bacteria/endotoxin. Hemoperfusion is a promising treatment, but is not universally effective and can unacceptable blood damage. We are developing protein-repellent hydrogel nanofilms that can be grown on a variety of surfaces, and functionalized with “click-ready” pathogen-binding proteins expressed by Genetic Code Expansion (GCE). The extremely rapid, bioorthogonal “click” immobilization chemistry eliminates prior purification, maximizes surface loading, and guarantees spatial orientation of the immobilized proteins. We have demonstrated pathogen binding and blood protein repulsion by these layers, suggesting that they may be part of effective treatments for sepsis and other applications.

Molecular Modeling Of Antibody-Antigen Binding Near Solid Surfaces, Derek Bush, Thomas Knotts

Biomedical Engineering Western Regional Conference

Antibody microarrays are biosensors that have the potential to revolutionize molecular detection in medicine, scientific research, and national defense. However, current microarrays are not widely used due to problems including poor reproducibility and signal quality, unbalanced antibody performance, and cross-reactivity. Prior work in the area focused mainly on the stability of the antibody alone and not its affinity for its antigen. This presentation shows results of using molecular simulation to determine how different types of surfaces affect antigen binding to surface-tethered antibodies. The results offer an unprecedented, molecular-level view into these protein-protein-surface interactions and how to drive binding to occur.