Engineering Commons^™

Lactonic Sophorolipid Increases Surface Wettability Of Poly- L -Lactic Acid Electrospun Fibers, Alexis M. Ziemba, Keith P. Lane, Bailey Balouch, Anthony R. D'Amato, Filbert Totsingan, Richard A. Gross, Ryan J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

The hydrophobicity of electro spun poly-l-lactic acid (PLLA) fibers hinders their integration with surrounding tissue for a variety of applications. In this study, we increased PLLA fiber hydrophilicity by incorporating the natural surfactant, lactonic sophorolipid (LSL). PLLA+LSL fibers had similar fiber morphology but significantly greater surface wettability, which suggested LSL accumulation on the fiber surface. Differential scanning calorimetry results also suggested that LSL was phase separated from PLLA. Despite the altered surface wettability of these fibers, there was no change in fibroblast adhesion. Future studies may explore the use of this natural surfactant to deliver bioactive factors to enhance fibroblast …

Assessment Of The Biocompatibilty, Stability, And Suitability Of Natural And Synthetic Polymers And Drugs In The Fda Approval Process, Phuong Anh Hoang Nguyen

Biomedical Engineering ETDs

Regulation of the development, production, marketing, and sales of medical pharmaceuticals and devices in the United States fall under the regulatory functions of the Food and Drug Administration (FDA). The current FDA approval process takes an average of 10 years from start to completion, and costs over $100 million. As a result, companies use many different methods to find additional use of their drugs through marketing directly to the physician, or recycling of previously approved drug moieties. In this work, an evaluation of the in vitro and ex vivo biocompatibility of polymers and drugs in different phases of FDA approval …

Identifying Extracellular Matrix Protein Turnover Rates For Tissue Engineers, Alita F. Miller

The Journal of Purdue Undergraduate Research

No abstract provided.

Multi-Dimensional Extension Of The Alternating Minimization Algorithm In X-Ray Computed Tomography, Jingwei Lu

McKelvey School of Engineering Graduate Student Theses & Dissertations

X-ray computed tomography (CT) is an important and effective tool in medical and industrial

imaging applications. The state-of-the-art methods to reconstruct CT images have had

great development but also face challenges. This dissertation derives novel algorithms to

reduce bias and metal artifacts in a wide variety of imaging modalities and increase performance

in low-dose scenarios.

The most widely available CT systems still use the single-energy CT (SECT), which is

good at showing the anatomic structure of the patient body. However, in SECT image

reconstruction, energy-related information is lost. In applications like radiation treatment

planning and dose prediction, accurate energy-related information …

Mechanosensitive Epithelial Cell Scattering And Migration On Layered Matrices, Christopher Michael Walter

McKelvey School of Engineering Graduate Student Theses & Dissertations

Epithelial cells form multi-layered tissue scaffolding that makes up every organ in the body. Along with epithelial cells, the basement membrane (BM) and connective tissue are composed of various proteins that sculpt the organs and protect them from foreign macromolecules. Epithelial cells respond to various cues, both chemical and mechanical, from their surrounding matrices to aid in maintenance and repair of these layers through degradation and deposition of extracellular matrix (ECM) proteins. In cancer progression, epithelial cells lose their normal function of supporting tissue structure and instead adopt more aggressive behaviors through an epithelial-to-mesenchymal transition (EMT) of their cellular traits. …

Understanding Excitation Energy Quenching In Isia, Hui-Yuan Steven Chen

McKelvey School of Engineering Graduate Student Theses & Dissertations

Cyanobacteria are photoautotrophic organisms that contribute a significant amount of global primary productivity. They are found in freshwater, marine and even some extremely severe environments. Among those environments, iron deficiency is one of the most common stress conditions in cyanobacterial habitats. To survive, cyanobacteria have evolved and developed several strategies to alleviate the damage caused by iron deficiency.

Iron stress-inducible protein (IsiA) is a chlorophyll-binding membrane protein found in cyanobacteria grown in iron-deficient conditions. During the past decades, considerable effort has been put on understanding how IsiA functions to help cyanobacteria survive iron deficiency. It has been reported that IsiA …

Metabolic Engineering Of Cyanobacteria For Production Of Chemicals, Po-Cheng Lin

McKelvey School of Engineering Graduate Student Theses & Dissertations

Concerns over the impact of climate change caused by CO2 emission have driven the research and development of renewable energies. Microbial production of chemicals is being viewed as a feasible approach to reduce the use of fossil fuels and minimize the impact of climate change. With recent advances in synthetic biology, microorganisms can be engineered to synthesize petroleum-based chemicals and plant-derived compounds. Cyanobacteria are photosynthetic prokaryotes that use only sunlight, CO2, and trace minerals for growth. Compared to other microbial hosts, cyanobacteria are attractive platforms for sustainable bioproduction, because they can directly convert CO2 into products. However, the major challenge …

Joint Reconstruction For Single-Shot Edge Illumination Phase-Contrast Tomography (Eixpct), Yujia Chen

McKelvey School of Engineering Graduate Student Theses & Dissertations

Edge illumination X-ray phase-contrast tomography (EIXPCT) is an emerging X-ray phasecontrast tomography technique for estimating the complex-valued X-ray refractive index distribution of an object with laboratory-based X-ray sources. Conventional image reconstruction approaches for EIXPCT require multiple images to be acquired at each tomographic view angle. This contributes to prolonged data-acquisition times and elevated radiation doses, which can hinder in vivo applications. In this dissertation, a new “single-shot” method without restrictive assumptions related to the object, imaging geometry or hardware is proposed for joint reconstruction (JR) of the real and imaginary-valued components of the refractive index distribution from a tomographic data …

A Modular Approach For Modeling, Detecting, And Tracking Freezing Of Gait In Parkinson Disease Using Inertial Sensors, Prateek Gundannavar Vijay

McKelvey School of Engineering Graduate Student Theses & Dissertations

Parkinson disease, the second most common neurodegenerative disorder, is caused by the loss of dopaminergic subcortical neurons. Approximately 50% of people with Parkinson disease experience freezing of gait (FOG), a brief, episodic absence or marked reduction of forward progression of the feet despite the intention to walk. FOG causes falls and is resistant to medication in more than 50% of cases. FOG episodes can often be interrupted by mechanical interventions (e.g., a verbal reminder to march), but it is often not practical to apply these interventions on demand (e.g., there is not usually another person to detect an FOG episode …

Metabolic Engineering Of Cyanobacteria For Production Of Chemicals, Po-Cheng Lin

McKelvey School of Engineering Graduate Student Theses & Dissertations

Concerns over the impact of climate change caused by CO2 emission have driven the research and development of renewable energies. Microbial production of chemicals is being viewed as a feasible approach to reduce the use of fossil fuels and minimize the impact of climate change. With recent advances in synthetic biology, microorganisms can be engineered to synthesize petroleum-based chemicals and plant-derived compounds. Cyanobacteria are photosynthetic prokaryotes that use only sunlight, CO2, and trace minerals for growth. Compared to other microbial hosts, cyanobacteria are attractive platforms for sustainable bioproduction, because they can directly convert CO2 into products. However, the major challenge …

Multi-Dimensional Extension Of The Alternating Minimization Algorithm In X-Ray Computed Tomography, Jingwei Lu

McKelvey School of Engineering Graduate Student Theses & Dissertations

X-ray computed tomography (CT) is an important and effective tool in medical and industrial imaging applications. The state-of-the-art methods to reconstruct CT images have had great development but also face challenges. This dissertation derives novel algorithms to reduce bias and metal artifacts in a wide variety of imaging modalities and increase performance in low-dose scenarios. The most widely available CT systems still use the single-energy CT (SECT), which is good at showing the anatomic structure of the patient body. However, in SECT image reconstruction, energy-related information is lost. In applications like radiation treatment planning and dose prediction, accurate energy-related information …

Monitoring Silane Sol-Gel Kinetics With In-Situ Optical Turbidity Scanning And Dynamic Light Scattering, Abul Bashar Mohammad Giasuddin, David W. Britt

Biological Engineering Faculty Publications

Organosilanes (e.g., R’-SiOR₃) provide hydrophobic functionality in thin-film coatings, porous gels, and particles. Compared with tetraalkoxysilanes (SiOR₄), organosilanes exhibit distinct reaction kinetics and assembly mechanisms arising from steric and electronic properties of the R’ group on the silicon atom. Here, the hydrolysis and condensation pathways of n-propyltrimethoxy silane (nPM) and a tri-fluorinated analog of nPM, 3,3,3-trifluoropropyl trimethoxy silane (3F), were investigated under aqueous conditions at pH 1.7, 2.0, 3.0, and 4.0. Prior to hydrolysis, 3F and nPM are insoluble in water and form a lens at the bottom (3F) or top (nPM) of the solutions. This …

Workshop On Convergence In Biological Engineering, Keith Roper

Funded Research Records

No abstract provided.

Genome-Edited Animals Are Not Transgenic Animals: Moving Toward Responsible Research And Innovation With New Biotechnologies, Yvie Yao

Minnesota Journal of Law, Science & Technology

No abstract provided.

Investigation Of The Electrode Polarization Effect For Biosensor Applications, Anil Koklu

Mechanical Engineering Research Theses and Dissertations

My research focuses on electrokinetic transport. Particularly, in this dissertation, we focus on fabrication and testing of micro electrodes with nanostructured surfaces to minimize the electrode polarization (EP) effects for biosensor applications. In the first study, electrochemical deposition of gold nanoparticles on to planar gold electrodes was used to generate rough surfaces. Dendritic nanostructures that reduced EP up to two orders of magnitude was obtained by optimizing the deposition conditions. These structures also enhanced dielectrophoresis (DEP) response of our bio-chips, making them usable in physiological buffers. In further studies we discovered a universal scaling of EP in the frequency domain, …

Application Of Micro-Scale 3d Printing In Pharmaceutics, Andrew Kjar, Yu Huang

Biological Engineering Faculty Publications

3D printing, as one of the most rapidly-evolving fabrication technologies, has released a cascade of innovation in the last two decades. In the pharmaceutical field, the integration of 3D printing technology has offered unique advantages, especially at the micro-scale. When printed at a micro-scale, materials and devices can provide nuanced solutions to controlled release, minimally invasive delivery, high-precision targeting, biomimetic models for drug discovery and development, and future opportunities for personalized medicine. This review aims to cover the recent advances in this area. First, the 3D printing techniques are introduced with respect to the technical parameters and features that are …

Measuring Impacts Of Uncertainty, Irreversibility, And Loss Aversion On The Adoption Of Crop Canopy Sensors Among Nebraska Corn Producers, Brooks Ronspies

Department of Agricultural Economics: Dissertations, Theses, and Student Research

Understanding barriers to adoption of Precision Agricultural Technologies (PATs) is important to the growth of agricultural productivity, efficiency, and sustainability. This thesis proposes and evaluates a model for estimating the impact of uncertainty, irreversibility, and loss aversion on producers’ adoption of crop canopy sensors in order to explain adoption behavior that contradicts previous expectations about the conditions necessary for technology adoption. The model is evaluated using estimated statistical distributions of price and field characteristics designed to match observations of actual corn and nitrogen prices, and of conventional and crop canopy sensor based nitrogen application. Results from this model using expected …

Metal Related Nanoparticles' Physical Behaviors In Different Physiologica Environments, Muhetaer Tuerhong

Master's Theses

In the past decades, the development of nanotechnology has had tremendous successes in material science. In this technology, the pertinent materials are used at the intermediate scale between individual molecules and their size in the nanometer region(1-100nm) compared to bulk materials. This nanoscale size provides a larger surface area; therefore, nanoparticles would be perfect essential components of nanotechnology. The reduced size of nanoparticles has a larger surface ratio to volume, which can modify their chemical, mechanical, structural, and electrical properties.

In this study, the main goal is to test different metal related nanoparticles, such as CuNPs (Copper nanoparticles), FeNPs (Iron …

Generation Of A Ccl2 Knockout Using Crispr/Cas9 And Lipid Mediated Transfection In Ct-26 Murine Colon Carcinoma Cells, Emma Sullivan

Biomedical Engineering Undergraduate Honors Theses

CCL2 is an inflammatory mediator that is released by tumor cells to activate and direct immune cell species, especially macrophages, to inflammatory sites within the body. The goal of this project was to successfully generate knockout the CCL2 ligand gene using a CRISPR/Cas9 complex delivered via lipid mediated transfection. The sgRNA and Cas9 mRNA were introduced into the cells via lipid-mediated transfection. The cells were incubated for 4 days, before being analyzed using PCR and gel electrophoresis. We expected to see one band on the first gel and two bands on the second gel. Two bands appeared on the first …

Design, Development, And Validation Of A Novel Optical Imaging Device For Biomedical Applications, Ashley Christine Dacy

Bioengineering Dissertations - Archive

Fluorescence and luminescence imaging are two promising optical techniques for diagnosing a variety of critical pathologies in vivo, including wound healing, inflammation, and vascular diseases. Despite this, there is a lack of imaging devices in research and commercially available that are capable of these imaging modalities in large animal applications. This work describes the progressive development of several optical imaging devices to fill this void, culminating in a final design with robust fluorescence and luminescence functionality designed for large animal and human applications. These devices are used to gather new data about various physical parameters in small and large animal …

Ultrasound Switchable Fluorescence Imaging Based On A Time Gated Iccd Camera, Shuai Yu

Bioengineering Dissertations - Archive

Ultrasound switchable fluorescence (USF) imaging has been proposed as a novel imaging modality which provides microscopic fluorescence imaging in centimeter-deep tissue. USF is possible to reveal many interesting phenomena such as microcirculation, tumor angiogenesis, and cancer metastasis and diagnose early-stage cancer. USF adopts a focused ultrasound (FU) to repetitively switch “on” fluorescent agents in tissue, and the USF photons scatter out and are captured by a detector. A USF image provides acoustic resolution and optical sensitivity. In USF, there are two key components: 1) an excellent USF contrast agent; and 2) a sensitive USF imaging system. The major challenge of …

Novel Analysis Of Wavelet Coherence And Phase-Amplitude Coupling To Investigate The Human Brain At Four Vigilance States, Seyedeh Parisa Rabbani

Bioengineering Dissertations - Archive

Despite breakthroughs in the field of neuroimaging, there remain many unanswered questions about brain functions and activities and their underlying physiological processes. In my dissertation research, I examined brain functions while human subjects experienced four vigilance states: (1) resting state with eyes open, (2) resting awake state with eyes closed, (3) sleep stage 1 and (4) sleep stage 2. Simultaneous dual modality measurements using electroencephalography (EEG) and functional near infrared spectroscopy (fNIRS) were acquired during the aforementioned vigilance states. Specifically, I examined brain processes from two different perspectives: brain hemodynamics (blood flow) and electrophysiology (brain waves). My dissertation had three …

Development And Investigation Of Fluorescence Imaging Probes, Bahar Saremi

Bioengineering Dissertations - Archive

Fluorescence imaging has attracted much attention due to high sensitivity, spatial and temporal resolution, and fast acquisition time, for imaging biomolecular processes and for diagnosis of diseases such as cancer in early stages. Fluorescence imaging in centimeter-deep tissue suffers from low spatial resolution because of the strong scattering of light. On the other hand ultrasound imaging benefits from 1000 times less scattering in the tissue and deep penetration. Ultrasound switchable fluorescence imaging is a relatively new imaging modality that combines the sensitivity of optical imaging with the depth of penetration of ultrasound imaging while preserving the resolution by only eliciting …

Lung Cancer Targeted Chemotherapy Via Herceptin Based Chimeric Antigen Receptor (Car) Engineered T Cell Membrane Coated Synthetic Nanoparticles, Serkan Yaman

Bioengineering Dissertations - Archive

Cell membrane-derived nanoparticles recently caught attention due to their desirable features in drug delivery such as mimicking properties of native tissue and cells, avoiding systemic clearance, and alleviating foreign body responses. Besides nanoparticle technology, adoptive immunotherapy has emerged for its promising treatment modalities, including cancer specificity. Our long-term goal for this research is to develop a biomimetic drug carrier based on chimeric antigen receptor (CAR) transduced T cell membranes. In the study, anti-cancer drug afatinib loaded poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles (NPs) co-extruded with anti her-2 based chimeric antigen receptor (CAR) Jurkat T cell membranes. Anti her-2 CAR-T cells were produced by …

Development Of Medical Devices For Diagnosing Cartilage Injury And Metastatic Cancers, Yi Hui Huang

Bioengineering Dissertations - Archive

My research focused on applying biomedical engineering techniques to diagnose different diseases and conditions. The results of these work led to one published paper and two submitted manuscripts which are summarized in Chapters 2, 3 &4. Briefly, in Chapter 2, my work laid emphasis on developing a method for early detection of cartilage injury. An apoptotic cell-detecting probe was fabricated by the conjugation of the apoptotic cell-binding peptide (CQRPPR) and a sulfo-cyanine7 N-hydroxysuccinimide ester (Cy7 dye). Both in vitro and ex vivo examination showed an excellent relationship between the number of apoptotic chondrocytes and probe binding affinity. Finally, using a …

Application Of Tissue Engineering Techniques For Treating Cartilage Injury And Diagnosing Cancer Metastasis, Amirhossein Hakamivala

Bioengineering Dissertations - Archive

This study focuses on the application of tissue engineering techniques for the diagnosis of cancer metastasis, cartilage regeneration, and modeling of lymph node metastasis. Chapter 1 is an overview of tissue engineering strategies, and it describes how each chapter relates to the central theme. Chapter 2 describes the development of 3D lymph node (LN) mimetic for studying prostate cancer metastasis. The overall objective of this chapter was to develop a biosystem with the ability to mimic metastatic LN condition. Studies were first designed to uncover the critical cells types and chemokines responsible for cancer metastasis to the LNs. An LN …

Development Of An In Vitro Tbi Models And Validation Of Nanodelivery For Restoration Of Disrupted Brain Endothelium, Edidiong I. Inyang

Bioengineering Dissertations - Archive

Blast-induced traumatic brain injury (bTBI) is a serious concern among military personnel and their families. Although the mechanisms responsible for disruption to the brain are not well understood, the development of reliable diagnosis along with effective therapeutic treatment is urgently warranted. Recent findings suggest that shockwaves produced by a blast can generate micron-size bubbles that subsequently collapse in the brain tissue. The collapse of microbubbles (referred to as microcavitation) may compromise the integrity of the blood-brain barrier (BBB). Moreover, addiction to the psycho-stimulant drugs (PSDs), e.g. cocaine and alcohol which are known to cause toxicity due to oxidative stress, can …

Development Of A Low Profile, Endoscopic Implant For Long Term Brain Imaging, Benjamin Scott Kemp

Doctoral Dissertations

The increased public awareness of concussion and traumatic brain injury has motivated continued research into the brain, its functions, and especially its response to injury, with a focus on improving the brain’s repair capabilities. However, due to the critical nature of the tissue, it is currently difficult for researchers to acquire high resolution images below the cortex without sacrificing a lab animal. Sacrificing an animal greatly reduces the amount of data that can be obtained from it, making longitudinal studies unappealing or unfeasible because a large number of animals is needed to obtain useful data over multiple time points. Additionally, …

Bioactive Glass Fiber Fabrication Via A Combination Of Sol-Gel Process With Electro-Spinning Technique, Malvika Nagrath, Adel Alhalawani, Alireza Rahimnejad Yazdi, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

No abstract provided.

Customization Of Aneurysm Scaffold Geometries For In Vitro Tissue-Engineered Blood Vessel Mimics To Use As Models For Neurovascular Device Testing, Camille D. Villadolid

Master's Theses

Cerebral aneurysms occur due to the ballooning of blood vessels in the brain. Rupture of aneurysms can cause a subarachnoid hemorrhage, which, if not fatal, can cause permanent neurologic deficits. Minimally invasive neurovascular devices, such as embolization coils and flow diverters, are methods of treatment utilized to prevent aneurysm rupture. The rapidly growing market for neurovascular devices necessitates the development of accurate aneurysm models for preclinical testing. In vivo models, such as the rabbit elastase model, are commonly chosen for preclinical device testing; however, these studies are expensive, and aneurysm geometries are difficult to control and often do not replicate …