Biomedical Engineering and Bioengineering Commons^™

A Comparison Of Optical Measurement Methods For The Growth Of S. Cerevisiae, Jackson Black

Chemical Engineering Undergraduate Honors Theses

Genetic engineering of living organisms provides the opportunity to express and harvest different proteins from cell surfaces. Yeast (S. cerevisiae) is one such organism and is capable of being grown on an industrial scale. Cellular concentration is an important parameter to monitor while fermentation processes are underway, in order to control the environment inside the growth medium and maximize yields. Spectrophotometry is a conventional method for measuring concentration, but is limited by a narrow absorbance range, and the need for on-site periodic sampling. A continuous method of measurement, as provided by Bug Labs BE2100 non-invasive biomass monitor, would …

Synthesis, Radiolabeling And Evaluation Of A Suite Of Tracers With 44Sc For Detecting Extracellular Dna, Zhiyao Li

McKelvey School of Engineering Graduate Student Theses & Dissertations

Neutrophil extracellular traps involve the rapid translocation of DNA to the outside of the cell under certain stimuli. This structure forms a fibrous network that is able to limit the spread of pathogens and to kill microorganisms. It has also been shown to be present in various pathological processes such as inflammation, autoimmune diseases, and cancer metastasis. Currently, the formation process of NETs in vivo is being extensively studied. However noninvasive detection and quantitation has yet to be achieved. A class of PET tracers are described here that consists of a DNA dye as the backbone that is labeled with …

A Magneto-Rheological Platform To Dynamically Control Afterload In Engineered Micro Heart Muscles, David Schuftan

McKelvey School of Engineering Graduate Student Theses & Dissertations

Cardiovascular disease is the leading cause of death is the United States, accounting for nearly 1 in 5 deaths. Many types of cardiovascular disease are linked to the mechanical forces placed on the heart. However, how these mechanical forces exactly affect the cellular biology of the heart is not well defined. In vitro models using cardiomyocytes derived from human induced pluripotent stem cells enable researchers to develop medium throughput systems to study cardiac mechanobiology at the cellular level. Previous models have been developed to enable the study of mechanical forces such as cardiac afterload. However, most of these models require …

Light Sheet Microscopy Incubation Design And Control Scheme, Venkatanathan Kidambi

Honors Scholar Theses

The focus of the following paper is the development of a light sheet or selective plane illumination microscopy (LSM / SPIM) platform to support long duration three dimensional imaging of various cells and tissues. This paper describes the complete design and fabrication process behind the prototype, including a definition of light sheet microscopy and its differences from confocal microscopy, as well as existing open source selective plane microscopy literature and designs. The complete engineering design process as applied to the microscope design is described in detail. Specifically, this paper will focus on the development of an incubation chamber for light …

Preparing Homogenous Composites Of Collagen And Cellulose Nanocrystals For Tissue Engineering Research, Zachary Stanley

Biological and Agricultural Engineering Undergraduate Honors Theses

Advancements in medicine and our understanding of stem cells have led to a greater emphasis on further developing research focused on tissue engineering. This research has led to the rise of both two-dimensional and three-dimensional scaffolds that can be utilized to repair bone, skin, vascular, and potentially even nervous tissue. One of the prominent compounds used in modern scaffolds is collagen-based hydrogels due to their low antigenicity and ability to provide structure to cells. There is potential to further improve upon this three-dimensional scaffold by incorporating cellulose nanocrystals (CNCs) into a composite hydrogel with collagen. The addition would increase the …

Comprehensive Long- And Short- Read Sequencing Approaches To Screen The Mutational Landscape After Therapeutic Crispr-Editing For Duchenne Muscular Dystrophy, Mary Jia, Made Harumi Padmaswari, Landon Burcham, Shilpi Agrawal, Alexis Ivy, Abbey Bryan, Christopher E. Nelson

Biomedical Engineering Undergraduate Honors Theses

Duchenne muscular dystrophy (DMD) is an X-linked muscle wasting disease caused by mutations in the Dmd gene resulting in non-functional dystrophin. Adeno-associated virus (AAV)-mediated delivery of classical CRISPR systems resulting in double-stranded breaks (DSBs) has yielded promise as a curative DMD therapeutic. However, the consequences of AAV-CRISPR require more thorough characterization. PCR-enriched short-read amplicon sequencing at cut sites is the most common method of sequencing CRISPR editing, but PCR bias results in unreliable quantification of on-target edits. We analyze orthogonal long- and short-read sequencing approaches to screen the outcomes of CRISPR technologies at the DNA and RNA-level for DMD. We …

A Wheelchair-Bed Transfer Device For Patients With Limited Mobility, Malachie Nichols

Biomedical Engineering Undergraduate Honors Theses

As the population ages, eldercare becomes more important than ever, yet many caregivers lack the resources they need to safely do their jobs. For those who take care of a disabled loved-one at home or work as home health aides, basic tasks can be frustrating and even dangerous. The high physical demands of moving and lifting patients make injuries common among home health care workers. Musculoskeletal injuries to the back, shoulders, wrists, and hands are especially common. The use of transfer devices such as Hoyer lifts, slide boards, and gait belts help to make moving patients easier and safer, but …

Automated Segmentation Of Autofluorescence Lifetime Images Using A Convolutional Neural Network, Nicole Hooten

Biomedical Engineering Undergraduate Honors Theses

Chronic wounds affect nearly 1 out of every 50 people in the United States, decreasing quality of life and putting people with potential comorbidities at high risk for obtaining an infection. Wound healing progress in clinical settings is measured by tracking wound size and there are currently no non-invasive, quantitative measurement techniques. Previous studies have proposed nicotinamide adenine dinucleotide (NADH) autofluorescence lifetime (FLIM) imaging of the wound edge as a method to quantify the wound healing process by connecting the role of NADH in cellular metabolism to wound healing stage. However, evaluation of FLIM images is heavily subjective, as a …

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 …

Characterizing And Quantifying Shear-Induced Hemolysis In A Hollow Fiber Membrane System, Siddhi Bhat

Chemical Engineering Undergraduate Honors Theses

Clinical studies have shown that patients undergoing renal replacement therapy are more susceptible to developing hemolysis, or the rupturing of red blood cells. Rapid hemolysis can cause symptoms such as anorexia, vomiting, and even death in severe cases. The aim of this study is to identify how shear stress within a hollow fiber membrane impacts the level of hemolysis that occurs. This allows for the optimization of the ultrafiltration membranes that are typically used for hemofiltration treatments. The variables being studied are the radii of hollow fibers, number of fibers, and volumetric flow rate of blood being circulated. Here, we …

3d Printing With Photopolymerizable Polyester Resins For Resorbable Medical Device Applications, Mathew Murphy Stanford

All Dissertations

In the past decade, the healthcare industry has seen a significant increase in the use of additive manufacturing (AM or “3D printing”) with subsequent improvement in clinical outcomes.As an exceptional AM technology, vat-photopolymerization (VP), often called stereolithography, can create complex structures and has thus been adopted for a range of biomedical applications including surgical guides, temporary implants, and resorbable tissue scaffolds.However, limitations remain in the availability of photopolymerizable resin materials with appropriate mechanical performance, biodegradability, and biocompatibility for application to resorbable medical devices.

The objective of this work was to employ novel photopolymerizable polyester-based macromers in the development of resorbable …

Tumor Targeting Gold Nanoparticles For Delivery Of Rna And Dna Oligonucleotide Therapies For Glioblastoma., Nicholas Allen

Electronic Theses and Dissertations

Glioblastoma (GBM) brain tumors are highly aggressive gliomas due to genetic and cellular heterogeneity. Current GBM treatment consists of surgical resection of the tumor combined with radio- or chemo-therapies. While these treatments have increased the life expectancy for GBM patients up to 20 months, they have had little effect on the 5-year survival rate. The complex cellular and genetic composition of the tumor makes current treatments less effective long term. One approach to developing more effective GBM treatments is to customize nanoparticle-based drug delivery systems that can directly target the aberrant gene expression patterns within a particular GBM tumor. Delivery …

Xeno-Free Biomimetic Ecm Model For Investigation Of Matrix Properties On Astrocyte Cell Response, Bayan Saleh

Theses and Dissertations

Astrocytes are crucial in preserving the structural and functional integrity of the central nervous system (CNS). They participate in several physiological processes, such as the uptake of neurotransmitters, control of extracellular ion concentration, and preservation of the blood-brain barrier. Recent research has raised the possibility that astrocytes are also involved in the onset and development of Alzheimer's disease (AD). While the precise mechanisms underlying the development and progression of AD are not fully understood, recent research has suggested that age-related changes in the brain extracellular matrix (ECM) properties may play a critical role in the progression of the disease. Investigating …

Biodegradable Magnesium Materials Regulate Ros-Rns Balance In Pro-Inflammatory Macrophage Environment, Maria Paula Kwesiga, Amani A. Gillette, Seyedehfatemeh Razaviamri, Margaret E. Plank, Alexia L. Canull, Zachary Alesch, Weilue He, Bruce Lee, Roger J. Guillory Ii

Michigan Tech Publications, Part 1

The relationship between reactive oxygen and nitrogen species (ROS-RNS) secretion and the concomitant biocorrosion of degradable magnesium (Mg) materials is poorly understood. We found that Mg foils implanted short term in vivo (24 h) displayed large amounts of proinflammatory F4/80+/iNOS + macrophages at the interface. We sought to investigate the interplay between biodegrading Mg materials (98.6% Mg, AZ31 & AZ61) and macrophages (RAW 264.7) stimulated with lipopolysaccharide (RAW 264.7LPS) to induce ROS-RNS secretion. To test how these proinflammatory ROS-RNS secreting cells interact with Mg corrosion in vitro, Mg and AZ61 discs were suspended approximately 2 mm above a monolayer of …

The Influence Of Myoblast Implantation On Arteriogenesis In Mice With Diet-Induced Obesity, Rayana Gutierrez

Biomedical Engineering

Peripheral arterial occlusive disease (PAOD) is characterized by atherosclerosis, which is the buildup of plaque, consisting largely of cholesterol, in the arterial walls. This plaque accumulation eventually blocks blood flow to the limbs, causing symptoms such as intermittent claudication and tissue death in cases of critical limb ischemia. The body compensates for the reduced perfusion by enlarging pre-existing bypass arteries, known as collaterals, in a process called arteriogenesis. However, in many cases, collateral networks constructed through arteriogenesis fail to enlarge sufficiently or function effectively in patients. Therefore, the development of a therapeutic intervention specifically targeting this process would offer a …

Mitral Valve Imaging And Biomechanics: A Workflow Towards Computational Modeling And Validation, Sam Stephens

Graduate Theses and Dissertations

The mitral valve serves a critical role in healthy cardiac function by ensuring the unidirectional flow of oxygenated blood from the left atrium into the left ventricle. It experiences the highest pressures found within the heart and its closure is the result of a complex interaction of several different structures that, furthermore, are unique to each individual. Despite the valve’s vital role however, the specific function of these constituent structures is not fully understood. This, confounded by its asymmetric, personalized nature, make surgical interventions for the mitral valve far less effective than for its neighboring aortic valve. Efforts to overcome …

The Influence Of Pesticides On Us Corn Production Environmental Impact: A Comparative Life Cycle Assessment Of Dominant Production Practices, Kyle Marinoni Lawrence

Graduate Theses and Dissertations

In recent years there has been increasing interest in reducing agricultural environmental footprints in the United States, particularly for commodity crops like corn grain. Pest management is one aspect of agricultural production that is often identified as having potential for improvement with regard to environmental impact, but there is not a robust body of literature to identify the wide-scale influence of pesticides on yield and environmental impact. In this study, we hypothesized that the use of different classifications of pesticides has a significant impact on the overall environmental impact. To test this, agricultural models were created to represent the dominant …

Nanosecond Pulsed Electric Field Modulates Electron Transport And Mitochondrial Structure And Function, Lucas Nelson Potter

Biomedical Engineering Theses & Dissertations

Pulsed power treatment has been used to induce regulated cell death (RCD) in cells or ablate tumors in animals. A subset of pulsed power as electroporation with high voltage and pulse duration of milliseconds is used for biomedical treatment to induce pores in the plasma membrane of cells. Nanosecond Pulsed Electric Fields (nsPEFs)– an extension of electroporation, uses waveforms with pulse durations on the order of 10-900 nanoseconds. nsPEF treatment has demonstrated intracellular effects for potential biomedical applications. In this work, nsPEF treatment is used to demonstrate changes that affect viability, plasma membrane permeability ROS (Reactive Oxygen Species) in the …

Wearable Sensor Gait Analysis For Fall Detection Using Deep Learning Methods, Haben Girmay Yhdego

Electrical & Computer Engineering Theses & Dissertations

World Health Organization (WHO) data show that around 684,000 people die from falls yearly, making it the second-highest mortality rate after traffic accidents [1]. Early detection of falls, followed by pneumatic protection, is one of the most effective means of ensuring the safety of the elderly. In light of the recent widespread adoption of wearable sensors, it has become increasingly critical that fall detection models are developed that can effectively process large and sequential sensor signal data. Several researchers have recently developed fall detection algorithms based on wearable sensor data. However, real-time fall detection remains challenging because of the wide …

Cardiac Ablation And Stimulation With Nanosecond Pulsed Electric Fields (Nspefs), Federica Serra

Biomedical Engineering Theses & Dissertations

Surgical ablation of cardiac tissue is the definitive treatment for the most common arrhythmia, atrial fibrillation. In current medical practice, myocardial tissue is often ablated by the application of radiofrequency (RF) currents which are delivered through an electrode to create lesions that block the electrical pathways that sustain reentrant arrhythmias and restore the normal heart rhythm. An alternative to RF is cryoablation, during which the endocardial or epicardial tissue is brought in contact with a cryoprobe. Both RF ablation and cryoablation have significant limitations. In RF ablation, tissue is heated in order to ablate it, but it is an open …