Biomedical Engineering and Bioengineering Commons^™

Simulation Of A Continuum Tumor Model Using Distributed Computing., Dylan A Goodin

Electronic Theses and Dissertations

Mathematical modeling aims to provide a theoretical framework for understanding tissue dynamics and for establishing treatment response for diseased tissues, such as tumors. Previously published continuum models have successfully represented idealized two-dimensional and three-dimensional tissue for short periods of time. A recently published continuum model of cancer increases model complexity and describes three-dimensional tissue that, due to the required complexity of the geometric multigrid solver, can only be feasibly applied to millimeter-scale simulations. Furthermore, the computational cost for such models has hindered their application in the laboratory and in the clinic. With computational demands greatly outpacing current openMP-based approaches on …

Feasibility Study Of Intelligent Lvad Control For Optimal Heart Failure Therapy., John A. Karlen Iii

Electronic Theses and Dissertations

Background: Left ventricular assist devices (LVAD) are operated at constant speeds (rpm), consequently, pump flow is passively determined by the pressure difference between the LV and aorta. Since the diastolic pressure gradient (~70 mmHg) is much larger than the systolic gradient (~10 mmHg), the majority of pump flow occurs during systole. This limitation results in sub-optimal LV volume unloading, LV washing, and diminished vascular pulsatility that may be associated with increased risk for clinically-significant adverse events, including stroke, bleeding, arteriovenous malformations, and aortic insufficiency. To address these clinical adverse events, an intelligent control strategy using pump speed modulation was developed …

Controlling Co Dose From Corm-Loaded Electrospun Scaffolds With Diffusion-Based Modeling And Experimental Assessment Of Endothelial Cell Response, Kenyatta S. Washington

Theses and Dissertations

Cardiovascular disease (CVD) accounts for one in every five deaths in the United States alone due to occlusion in small diameter (< 6 mm) vessels. The current treatment options includes bypass grafting; however, more than 30 percent of patients do not have viable saphenous veins for autologous grafting [1]. Therefore, tissue engineering is being considered as an alternative approach. The overall goals of this project were to develop a tissue engineered vascular graft with the incorporation of carbon monoxide releasing molecules (CORMs) and to determine the impacts of carbon monoxide (CO) on endothelial cells (ECs) with the goal of promoting a functional endothelium within the graft. This was accomplished through two complementary studies: investigating the impacts of CO-loaded electrospun scaffolds on ECs for cardiovascular applications and diffusion-based modeling of drug delivery of gasotransmitters from tissue engineered scaffolds. In the first study, we extended the maximum in vitro incubation time to permit better cellular attachment and proliferation with a newly-synthesized, more hydrophobic CORM (DK3) and established the impact of CORMs on EC viability and function (e.g. reactive oxygen species (ROS) products, and ROS levels). We further investigated toxicity and biocompatibility of a newly synthesized CORM (DK4) loaded within PCL thin films and nanoparticles. We concluded that the DK4 and other compounds are not toxic at doses ranging from 0 – 50 μg/mL to the ECs both within nanoparticles that can be internalized within cells. We also conducted an in vivo pilot study to determine graft biocompatibility and preliminary results showed that CORM implants maintain mechanical integrity, support blood flow, and do not show toxicity for up to six weeks. In the second study, we validated a computational model and analyzed the output of CO delivery to better understand and control local dose. For CO release, this model is necessary because of the limitations with real-time experimental analysis and the need to better understand the dose available to the cells. We demonstrated that the validated model can be used to predict drug availability to cells for a variety of scaffolds and drug molecules. Our simulated results suggest that only a fraction of the initial concentration of gasotransmitters released from fibers that enters the interstitial fluid in vivo, or culture media in vitro, will be available to cells. We also demonstrated that fiber orientation and fiber diameter are important for drug delivery, but fiber density provides even more important information. The more contact area within the fiber scaffolds is equivalent to experimental conditions with more cell attachment and spreading. These parameters are not only important for traditional tissue engineering, but also for drug delivery. Overall, these results demonstrate the feasibility of making a tissue engineered vascular graft with the incorporation of CORMs and validating he importance of computational modeling of diffusion-based transport of CO. Future work will involve performing surface modifications to enhance cell attachment and proliferation, using the developed computational model to better predict dose available to cells, and experimentally determining impact of CO dose on ECs.

Gene Expression Studies For Analyzing Effects Of Space Radiation In Tissues, Amatulshakoor Mohammed Farooqui

Theses and Dissertations

Human exploration beyond the earth's orbit poses many risks for the crew on these missions. One of the major health risks is exposure to space radiation environment beyond the earth’s magnetic field. The space environment exposes astronauts to high levels of ionizing radiation such as galactic cosmic rays. The radiations can have acute and delayed effects on the human body. The primary response to tissue injury is increased oxidative stress and inflammation. The overall objective of this study was to analyze the effects of ionizing radiation in heart tissue by quantifying its impact on the expression of genes that correlate …

Experimental Methods And Techniques For Improved Biomechanical Characterization Of Diverse Murine Aortopathies, Brooks Alexander Lane

Theses and Dissertations

Aortopathies constitute a broad class of diseases affecting the aorta – the largest artery responsible for distributing oxygenated blood to the systemic circulation. Specifically, aortic aneurysms (AAs) are described as a focal dilation of the vascular wall exceeding 50% of the normal vessel diameter. Ultimately AAs may stabilize, dissect, or rupture, with the latter virtually ensuring mortality. Currently clinicians consider prophylactic intervention based on size and growth-rate criteria that have been estimated from large-cohort statistical analyses. These criteria, however, fail to address the underlying mechanisms. Furthermore, 13% of small-to-mid sized AAs have been found to rupture prior to meeting these …

A Ph-Sensitive Delivery System For The Prevention Of Dental Caries Using Salivary Protein, Yi Zhu, Yizhi Xiao, Elizabeth Gillies, Walter L. Siqueira

Western Research Forum

Dental caries remains one of the most common chronic diseases worldwide. In previous studies, salivary proteins (e.g. histatin 3, statherin) have demonstrated biological functions including the inhibition of crystal growth, antibacterial activities, which are directly related to tooth homeostasis and prevention of dental caries. However, proteins are susceptible to the high proteolytic activities in the oral environment. Therefore, pH-sensitive chitosan nanoparticles (CNs) have been proposed as potential carriers to protect proteins against enzymatic degradation at physiological salivary pH, in addition to swell selectively at lower pH conditions to facilitate the release of the encapsulated proteins, as major oral complications occur …

The Effect Of Radial Head Hemiarthroplasty Stem Fit On Radiocapitellar Contact Mechanics: Is Loose Fit Better Than Rigidly Fixed?, Jakub Szmit, Graham J.W. King, James A. Johnson, G. Daniel G. Langohr

Western Research Forum

Background/Methods: Radial head hemiarthroplasty is commonly employed to manage comminuted displaced fractures. With regards to implant fixation, current designs vary with some prostheses aiming to achieve a tight 'fixed' fit, and others utilizing a smooth stem with an over reamed 'loose' fit. The purpose of the present study was to evaluate the effect of radial head hemiarthroplasty stem fit on radiocapitellar contact using a finite element model which simulated both fixed (size-for-size) and loose (1, 2 & 3mm over reamed) stem fits.

Hypothesis: It was hypothesized that a loose stem fit would improve radiocapitellar contact mechanics, with increased contact area …

Multifunctional Hybrid Sol-Gel Implant Coatings On Anodized Titanium Substrates To Improve Osseointegration And Antimicrobial Effectiveness, Zach Gouveia

Western Research Forum

To improve patient outcomes in orthopedic and dental implantation procedures, the development of multifunctional implant coatings that can inhibit microbial cell proliferation while promoting osseointegration have been sought out by clinicians. While recent developments in material science and cell biology have seen the development of such coatings, many proposed systems lack clinical translatability. For example, to reach the clinic, modern coating systems must be highly adherent to their substrate (to avoid delamination upon implantation), have sufficient wettability (to promote the fixation of cells), and facilitate the controlled and sustained release of antimicrobial factors (falling within the therapeutic window to prevent …

Fibrinogen, Factor Xiii And Fibronectin: A Biophysical And Kinetic Characterization Of Their Interactions, Frank Fabian

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

The development of recombinant-based liquid fibrin tissue sealants having enhanced hemostatic and wound healing properties will involve understanding as yet not well characterized interactions between fibrinogen, fibrin (Fbn) factor XIII, thrombin and fibronectin. We study these phenomena in the context of comparing plasma derived fibrinogen to recombinant fibrinogen (rFI) produced in the milk of transgenic cows. An abundance of purified γγ and γγ’ FI subspecies enables detailed study of γγ or γγ’ biomonomer and their respective Fbn biopolymer formation as having different substrate behaviors of activated plasma derived factor XIII (pFXIIIa₂b₂). High pressure size exclusion (HPSEC) …

Inverted Cone Convolutional Neural Network For Deboning Mris, Oliver John Palumbo

Theses and Dissertations

Data plenitude is the power but also the bottleneck for data-driven approaches, including neural networks. In particular, Convolutional Neural Networks (CNNs) require an abundant database of training images to achieve a desired high accuracy. Current techniques employed for boosting small datasets are data augmentation and synthetic data generation, which suffer from computational complexity and imprecision compared to original datasets. In this thesis, we intercalate prior knowledge based on the temporal relation between the images in the third dimension. Specifically, we compute the gradient of subsequent images in the dataset to remove extraneous information and highlight subtle variations between the images. …

Muscle Activation Via Mri: Comparison Of Techniques, Logan Thorneloe, Neal Bangerter

Journal of Undergraduate Research

Muscle functional magnetic resonance imaging (mfMRI) is a proven concept to non-invasively identify muscle activation1. Noninvasively identifying muscle activation can be used to diagnose metabolic muscle disease, identify and pinpoint muscular dysfunction, observe muscle deterioration in aging individuals, and help researchers better understand the biological foundation of musclechemistry2. Current proven methods of mfMRI include analyzing pre- and post-exercise T2-weighted images, T2 maps, and sodium images of muscle; however, there is considerable debate around the best of these techniques1-4. We tested these three imaging techniques to determine which has the greatest post-exercise shift in signal intensity.

Neurostimulator With Waveforms Inspired By Nature For Wearable Electro-Acupuncture, Jose Aquiles Parodi Amaya

LSU Doctoral Dissertations

The work presented here has 3 goals: establish the need for novel neurostimulation waveform solutions through a literature review, develop a neurostimulation pulse generator, and verify the operation of the device for neurostimulation applications.

The literature review discusses the importance of stimulation waveforms on the outcomes of neurostimulation, and proposes new directions for neurostimulation research that would help in improving the reproducibility and comparability between studies.

The pulse generator circuit is then described that generates signals inspired by the shape of excitatory or inhibitory post-synaptic potentials (EPSP, IPSP). The circuit analytical equations are presented, and the effects of the circuit …

Happy Hours Are A Godsend, Krishna Pakala, Diana Bairaktarova, Samantha Schauer

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Office hours that happen in a virtual environment are called virtual office hours. This type of student-faculty interaction can be easily hosted from a faculty computer/mobile device/tablet. With an invitation, students can login to the online session and join their instructor and peers in a virtual space. Using mobile technologies, students can join virtual office hours from a variety of locations including a library, outdoors, on a commute ride home, while caring for children, eating dinner, and even while grocery shopping. Virtual office hours allow for more flexibility of student-faculty interaction. They are an alternative to traditional office hours. This …

Work In Progress: First-Year Engineering College Students: Value Created From Participating In A Living/Learning Community, Krishna Pakala, Kim M.B. Tucker, Samantha Schauer

Mechanical and Biomedical Engineering Faculty Publications and Presentations

This Work in Progress paper examines how to capture the perceived value obtained from firstyear engineering college students (FYECS) from participating in the Engineering and Innovation Residential College (EIRC), a living learning community (LLC). People are social by nature and thrive through collaborating and living with others who share similar passions; however, oftentimes FYECS do not have a community of like-minded peers where support, innovation, discourse, and collaboration can take place. Adding to FYECS struggles is the fact that many do not have a mentor in their related field and are unable to start building their professional repertoire, network, technical …

Advanced Design And Fabrication Of Prosthetic And Medical Devices, Gaffar Gailani, Andy S. Zhang, Yu Wang, Sidi Berri

Publications and Research

The department of Mechanical Engineering and Industrial Design Technology (MEIDT) at City Tech is seeking to strengthening the skills of its students in manufacturing and design to respond to the urgent needs of the manufacturing industry in general and the prosthetic and medical devices (P&MD) industry in particular to high-skilled engineers and technicians and to provide a national model for advanced technology education. Medical Devices will include: (a) Surgical and Medical Instruments; (b) Surgical Appliances and Supplies; and (c) Dental Equipment and Supplies. The educational merit of the project is that it motivates students to do engineering rather than studying …

Scale Optimization Of Milkguard Biosensor For Detecting E. Coli In Human Breast Milk, Jerard Roniel Del Rosario Madamba

Bioengineering Master's Theses

Milkguard is an alginate-based biosensor developed to detect E. coli in human breast milk via the metabolism of X-gal (5-Bromo-4-Chloro-3-Indolyl β-D-Galactopyranoside) by β-galactosidase. In order to deconvolute metabolic reproducibility from scaling laws, the commercial enzyme β-galactosidase was used to mimic the biological function of the bacterial lac operon. Downscaling was explored as an optimization of the biosensor design based on numerical solutions to Fickian-based diffusion models. The characterization of large capsules (d ≅ 3 mm) and atomized microcapsules (d ≅ 300 ± 60 μm) yielded size-specific Michaelis-Menten constants. Small capsules (K_m = 3.6 x 10^-4 M; Vmax ’’ …

Unravel The Cellular Biophysical Dynamics Of Spatial Constraint-Induced Membrane Blebbing And 3d Migration Using A Microfluidic Platform And Data-Driven Mathematical Modeling, Yu Huang

Funded Research Records

No abstract provided.

Epic: Examining Patch Impedance Characteristics, Shane Buck, Jyotsna Gopinath, Kyle Markfield

Interdisciplinary Design Senior Theses

In the United States, approximately one in 4 adults have at least one chronic illness, making up approximately 84% of US Healthcare Spending. Unfortunately, 50% of patients with chronic diseases do not take their medication properly and as such spend more money trying to get better – approximately $100 billion in annual preventable costs. One solution to this issue is digital medicine as it allows for the monitoring of patient medicine consumption.

Our industry partner has developed a three-part digital medicine system with the aim of allowing patients with chronic health issues to better reach their health goals through monitoring …

Justrun - Social Gps Running Game, Riley Bergin, Maggie Cai, Simran Judge, Grace Ling

Interdisciplinary Design Senior Theses

With advances in technology allowing people to live more sedentary lives, more and more people are struggling to live a healthy active lifestyle. In the efforts to combat unhealthy styles of living, we wish to introduce a mobile app that takes advantage of motivational game mechanics to motivate players will make go on runs regularly.

Anti-Infective Mechanism-Based Drug Discovery Via Sortase A, Huong Chau, Alice Matsuda, Leepakshi Johar

Bioengineering Senior Theses

Sortase A is a transmembrane protein prominent in gram-negative bacterial strains. It is a virulence factor that anchors other proteins, which facilitate MRSA infections. In the long term, we plan to utilize this protein to create anti-infective drugs as antibiotic resistance continues to become a global health issue. Starting with five NIH drug candidates, we decided to first study Sortase A with B12 due to its historical past of ancient civilizations using natural sources of B12 to treat infections. Our senior design is further centered around understanding how vitamin B12 interacts with Sortase A in vitro, particularly the binding affinity …

Developing A Control System To Better Understand The Effects Of Pyruvate Decarboxylase Activity On Clostridium Thermocellum Metabolism, Nicholas Cervenka

ENGS 88 Honors Thesis (AB Students)

In order for cellulosic biofuels from Clostridium thermocellum to be commercially viable, the ethanol yield and titer of the microbe must be increased. To accomplish this, it has been suggested to introduce the Pyruvate Decarboxylase (PDC) enzyme into C. thermocellum. In order to demonstrate effects on ethanol production by PDC prior to genetic modification, a cell free system (CFS) has been developed. A purified enzyme system was developed with the CFS to function as a control. Using the purified enzyme system, PDC from Saccharomyces cerevisiae was demonstrated to be a good candidate for further testing in the CFS.

A Physical And Computational Reverse-Engineering Approach To Determine Dimensional Change And Its Relationship To Oxidation In Retrieved Orthopedic Implants, Josephine Kalshoven

ENGS 88 Honors Thesis (AB Students)

Oxidation of the Ultra-High Molecular Weight Polyethylene (UHMWPE) tibial inserts of total knee arthroplasty devices is a major factor underlying multiple modes of failure for these devices, including delamination, wear, and fracture. Previous research has demonstrated that oxidation of UHMWPE is driven by a high concentration of free radicals in the polyethylene. However, even new devices created with undetectable amounts of free radicals are oxidizing in vivo. One theory is that, in the absence of residual free radicals, oxidation is facilitated by absorbed species (e.g. lipids, ROS) delivered or exacerbated by contact stress. However, no method exists to comprehensively …

Maximizing And Modeling Malonyl-Coa Production In Escherichia Coli, Tatiana Thompson Silveira Mello

LSU Master's Theses

In E. coli, fatty acid synthesis is catalyzed by the enzyme acetyl-CoA carboxylase (ACC), which converts acetyl-CoA into malonyl-CoA. Malonyl-CoA is a major building block for numerous of bioproducts. Multiple parameters regulate the homeostatic cellular concentration of malonyl-CoA, keeping it at a very low level. Understanding how these parameters affect the bacterial production of malonyl-CoA is fundamental to maximizing it and its bioproducts. To this end, competing pathways consuming malonyl-CoA can be eliminated, and optimal nutritional and environmental conditions can be provided to the fermentation broth. Most previous studies utilized genetic modifications, expensive consumables, and high-cost quantification methods, making …

Conference Program, Erin Buckley, Christophe Moser, Brian Pogue, David Sampson

Advances in Optics for Biotechnology, Medicine and Surgery XVI [2019]

No abstract provided.

Compositional Optimization Of Amyloid-Graphene Oxide Nanohybrids For Biomaterials, Claire L. Drewery

Materials Engineering

Amyloid nanofibrils are natural materials capable of self-assembling into precise structures with tunable functionalities, while exhibiting excellent mechanical properties. In combination with highly conductive graphene oxide (GO), the 1-D amyloid nanofibrils and 2-D nanosheets of GO can produce a robust and bio-functional nanohybrid, hypothesized to exhibit multi-domain functional properties useful for enzyme sensing, water purification, drug delivery, and tissue scaffolding applications. Here, we examine the properties of an amyloid-graphene oxide nanohybrid film made with amyloids derived from hen egg white lysozymes in an attempt to explore the diverse toolbox of amyloid derivatives and establish ideal fabrication methods and formulations of …

In Vitro Evaluation Of 3d Printed Polycaprolactone Scaffolds With Angle-Ply Architecture For Annulus Fibrosus Tissue Engineering, Thomas R. Christiani, E Baroncini, Joseph F. Stanzione, Andrea J. Vernengo

Henry M. Rowan College of Engineering Departmental Research

Tissue engineering of the annulus fibrosus (AF) is currently being investigated as a treatment for intervertebral disc degeneration, a condition frequently associated with low back pain. The objective of this work was to use 3D printing to generate a novel scaffold for AF repair that mimics the structural and biomechanical properties of the native tissue. Multi-layer scaffolds were fabricated by depositing polycaprolactone struts in opposing angular orientations, replicating the angle-ply arrangement of the native AF tissue. Scaffolds were printed with varied strut diameter and spacing. The constructs were characterized morphologically and by static and dynamic mechanical analyses. Scaffold surfaces were …

Spatial Frequency Domain Imaging Of Short-Wave Infrared Fluorescence For Biomedical Applications, Joseph P. Leonor

ENGS 88 Honors Thesis (AB Students)

Fluorescence imaging has become a standard in many clinical applications, such as tumor and vasculature imaging. One application that is becoming more prominent in cancer treatment is fluorescence-guided surgery (FGS). Currently, FGS allows surgeons the ability to visually navigate tumors and tissue structures intraoperatively. As a result, they can remove tumor more efficiently while maintaining critical structures within the patient, creating better outcomes and lower recovery times. However, background fluorescence and inability to localize depth create challenges when determining resection boundaries.

Different techniques, such as spatially modulating the illumination and imaging at longer light wavelengths, have been developed to accurately …

Effects Of Glycation On Blood Protein Interactions With Nanomaterials: A Biophysical And Cytotoxicity Study, Karl Baumgartner, Madeline Eiken

Bioengineering Senior Theses

When engineered nanoparticles (NPs) enter into a biological system, the proteins and biomolecules in the system adsorb to the NP surface to form a “protein corona” (PC). The PC greatly influences NP transformations, biological interactions, and cell response. Further complicating the development of NPs for biomedical applications, disease states alter the population of proteins and changes the biophysical features of individual proteins through posttranslational modifications. Here-in, we aim to understand how glycation of the PC, as in uncontrolled diabetes, alters the NP-PC interaction and toxicity by conducting biochemistry and cell toxicity experiments. We focus upon 40 and 80 nm citrate-coated …

Evaluation Of Human Umbilical Vein Endothelial Cells In Blood Vessel Mimics Through Changes In Gene Expression And Caspase Activity, Conor Charles Hedigan

Master's Theses

Blood vessel mimics (BVMs) are simple tissue engineered blood vessel constructs intended for preclinical testing of vascular devices. This thesis developed and implemented methods to characterize two of these components. The first aim of this thesis investigated the effect of cell culture duration and flow conditions on endothelial cell gene expression, especially regarding endothelial-to-mesenchymal transition (EndMT). A trend of decreased endothelial marker gene expression and increased mesenchymal marker gene expression would indicate EndMT. qPCR analysis revealed that increased cell culture duration did not result in EndMT, and in fact increased endothelial marker expression as cell culture duration increased. Disturbed flow …

Interpolated Perturbation-Based Decomposition As A Method For Eeg Source Localization, Gabriel Zelik Lipof

Master's Theses

In this thesis, the perturbation-based decomposition technique developed by Szlavik [1] was used in an attempt to solve the inverse problem in EEG source localization. A set of dipole locations were forward modeled using a 4-layer sphere model of the head at uniformly distributed lead locations to form the vector basis necessary for the method. Both a two-dimensional and a pseudo-three-dimensional versions of the model were assessed with the two-dimensional model yielding decompositions with minimal error and the pseudo-three-dimensional version having unacceptable levels of error. The utility of interpolation as a method to reduce the number of data points to …