Other Biomedical Engineering and Bioengineering Commons^™

Fluorescent Imaging On A Microfluidics Chip For Quantification Of Leukocyte Count, Aneeka Majid

Biomedical Engineering Undergraduate Honors Theses

We have demonstrated a method for conducting a leukocyte count in whole blood using a microfluidics chip and epi-fluorescence setup. Leukocyte counts provide physicians with a wealth of information about a patient’s medical condition and as such are routinely completed for many hospital visits. Miniaturization of this diagnostic tool may enable physicians to provide healthcare in resource-limited settings, where patients would otherwise not receive this test. The microfluidics chip was fabricated in polydimethylsiloxane (PDMS) using soft-film lithography. Following further processing and cleaning, the PDMS mold is exposed to UV-ozone for surface activation, and then sealed with a glass coverslip to …

Monitoring The Effects Of Mmp Inhibitors On Extracellular Matrix Degradation For Use In Implant Protection, Jake D. Jones

Biomedical Engineering Undergraduate Honors Theses

In order to lengthen the functional time of implantable ECM, the mechanism of degradation must be inhibited. The matrix metalloproteases are the primary method by which ECM is broken down, and the TIMP family of proteins exists as proof that inhibition of these proteases is possible naturally. In particular, the glycoprotein TIMP-1 plays an inhibitory role with most of the MMPs including the collagenases. Furthermore, there exist synthetic or chemical molecules that likewise inhibit the catalytic actions of MMPs. One such molecule is Batimastat (BB-94) which has been proven to be a dose dependent inhibitor of MMPs during the inflammatory …

Development Of An In Vitro Myogenesis Assay, Anna Arnaud

Biomedical Engineering Undergraduate Honors Theses

The objective of this study was to explore the interaction between mouse C2C12 cells and the extracellular matrix, particularly the process of myoblasts converting to myocytes. This study aimed to create a myogenesis assay that presents a process to effectively monitor the development of mouse C2C12 myoblasts into differentiated skeletal myotubes through detection of the protein MyoD. Myogenesis, the development of muscle tissue, occurs when muscle progenitor cells, myoblasts, fuse to form multinucleated myotubes, followed by cell fusion and resulting in a myofiber capable of contraction. An in vitro myogenesis assay would enable further research to efficiently test the effect …

Multiplexed Microfluidic Loop-Mediated Isothermal Amplification Of The 16s Rrna Gene For The Diagnosis Of Neonatal Sepsis In Resource-Limited Environments, Griffin Thomas Sonaty

Biomedical Engineering Undergraduate Honors Theses

Bacterial infection, or sepsis, places a disproportionately high burden on newborns in developing countries. This is due in part to a lack of diagnostic tools suitable for sustainable use in resource-limited nurseries. One potential vehicle for a new diagnostic assay is loop-mediated isothermal amplification (LAMP), a high-yield DNA amplification method. LAMP has been used to detect single genes from bacteria in blood serum samples to aid in sepsis diagnosis. While specific, this approach can only provide detection for one species at a time. LAMP could be adapted to detect a broader set of bacteria, while retaining a degree of specificity …

Intracellular Uptake Of Chitosan Nanoparticle-Based Vaccines, Katherine E. Wilson

Biomedical Engineering Undergraduate Honors Theses

Particle-based delivery systems are a promising approach to enhance antigen-specific immunity for use in vaccines. Chitosan, a natural polysaccharide derived from the exoskeletons of crustaceans, shows great potential as a vaccine carrier due to its favorable properties as a biomaterial, including biocompatibility and biodegradability. In this study, the intracellular uptake of chitosan nanoparticles is explored and compared to that of other commonly used particle-based delivery vehicles, such as poly (lactic-co-glycolic acid) (PLGA). Fluorescein isothiocyanate-labeled bovine serum albumin (FITC-BSA) was used as a model protein antigen and encapsulated in both chitosan particles via precipitation-coacervation and PLGA particles via double emulsion solvent …

Long Term Blood Oxygenation Membranes, Joseph V. Alexander

Theses and Dissertations--Biomedical Engineering

Hollow fiber membranes are widely used in blood oxygenators to remove carbon dioxide and add oxygen during cardiopulmonary bypass operations. These devices are now widely used off-label by physicians to perform extracorporeal blood oxygenation for patients with lung failure. Unfortunately, the hollow fiber membranes used in these devices fail prematurely due to blood plasma leakage and gas emboli formation.

This project formed ultrathin (~100nm) polymer coatings on polymer hollow fiber membranes. The coatings were intended to “block” existing pores on the exterior surfaces while permitting high gas fluxes. This coating is synthesized using surface imitated control radical polymerization.

The coating …

Developent Of A Phospholipid Encapsulation Process For Quantum Dots To Be Used In Biologic Applications, Logan Grimes

Master's Theses

The American Cancer Society predicts that 1,665,540 people will be diagnosed with cancer, and 585,720 people will die from cancer in 2014. One of the most common types of cancer in the United States is skin cancer. Melanoma alone is predicted to account for 10,000 of the cancer related deaths in 2014. As a highly mobile and aggressive form of cancer, melanoma is difficult to fight once it has metastasized through the body. Early detection in such varieties of cancer is critical in improving survival rates in afflicted patients. Present methods of detection rely on visual examination of suspicious regions …

Validation Of A Diffuse Reflectance Microendoscope With Polydimethylsiloxane Optical Phantoms And Monte Carlo Modeling, Gage Joseph Greening

Biomedical Engineering Undergraduate Honors Theses

We have introduced a method for creating thin-film PDMS optical phantoms that can be used to validate a bench-top optical device called a Diffuse Reflectance Microendoscope (DRME). The DRME is acquires data on cell surface morphology and sub-surface diffuse reflectance, which may provide clinicians with the tools to diagnose oral cancer at earlier stages. Phantoms were created with PDMS. Optical properties of the phantoms were controlled with the addition of nigrosin and titanium dioxide. Depth of phantoms was controlled by a spin coater. The DRME was built with a combination of filters and dichroic mirrors to separate electromagnetic radiation in …

Poly (Glycerol Sebacate) Nanofibers And Nanofilms For Tissue Engineering Application, Stephanie Grace Cone

Biomedical Engineering Undergraduate Honors Theses

In the field of tissue engineering, the development of biodegradable scaffolds that provide both structure and functionality is a major challenge. The use of biological implants, such as decellularized tissues, provides a complete matrix with full tissue functionality, however, problems with immunogenicity often arise when implants from other organisms are used in treatments. As such, there are many benefits to the use of polymeric constructs in tissue engineering. The ability to customize the material, design, and size of an implant provides opportunities for increased structural support and controlled rates of biodegradation. The selection of polymers for tissue engineering applications requires …

Classification And Quantification Of Phenotypic Characteristics Of Normal And Dysplastic Oral Cells, Jackson W. Boice

Biomedical Engineering Undergraduate Honors Theses

Introduction Oral cancer accounts for 2.5% of all cancer cases in the United States. The 5 year survival rate or stage 1 or localized oral cancer is 82%, and the survival rate of unstaged oral cancer is only 50%; therefore, early diagnosis is key. Current clinical practices for determining malignancy of tissue include physical examination and surgical biopsy, which can be plagued by high variability between observers and are invasive for the patient. Proflavine intercalates between base pairs of nucleic acids and has excitation and emission peaks at 455 (+/- 20) nm and 515 nm respectively; therefore, it can be …

Optimizing In Vitro Extracellular Matrix Production Using Polymer Scaffolds With Targeted Pore Size, Addison M. Walker

Biomedical Engineering Undergraduate Honors Theses

Extracellular matrix (ECM) has been shown to provide the framework needed for healthy tissue to grow after experiencing an injury. The optimization of growing ECM is a pressing concern in the tissue regeneration field. From prior research, an in vitro approach for harvesting ECM has been created using polyurethane (PU) foams seeded with cells. Our approach aimed at discovering if the pore size of the foams increased the amount of recovered ECM. Scaffolds of targeted pore size were created by separating sugar granules using a sieve, packing the sugar into a cylindrical mold, then pouring PU over the sugar. Three …

How Imbalanced Excitation And Inhibition May Cause Low Entropy Brain Dynamics, Qusay Redwan Alfaori

Biomedical Engineering Undergraduate Honors Theses

To study the effect of the imbalance of excitation and inhibition neurons on brain entropy using a computer model of a brain. The brain model will be composed of a neural network and entropy of the neural network will be measured quantitatively. Entropy in this context quantifies how many different patterns of activated neurons the brain can create. Imbalance between excitation and inhibition neurons causes the brain to malfunction, which can be an underlying cause of autism.

5ht And The 5ht Receptors- Relevance To Cardiac Valve Disease, Christopher Ryan Martindale

Biomedical Engineering Undergraduate Honors Theses

Recent studies have revealed that elevated levels of serotonin or 5HT lead to valve dysfunction. A mouse model was successfully established to investigate the effects on the aortic valve in subjects with elevated 5HT levels along with cardiovascular hypertension. For each two-week trial, eight C57BL/6J mice were divided into the following expermental groups: control, 5HT, angiotensin II, and 5HT+angiotensin II. The drug was delivered to the mice via osmotic pumps (Ang II: 0.4ng/g/min, 5HT:0.0025ng/g/min) or direct injections(Ang II: 0.1 mg, 5HT: 2.12 mg, every other day) and the blood pressure of the mice was continually monitored via the CODA tail …

Modeling Of An Oxygenation-Aided 3d Culture For Functional Beta-Cell Expansion, John Lance Mcreynolds

Biomedical Engineering Undergraduate Honors Theses

Introduction: Diabetes affects millions of people and its prevalence is increasing by 2-5% per year. A promising method for the control of diabetes is the transplant of pancreatic β-cell mass. Unfortunately, there is a shortage of the donor tissue that is needed to replace β-cell mass. A potential source of β-cells is the production of β-cells in vitro, but the proliferation rate of β-cells is very slow and elevating the proliferation rate can result in loss of cell function. We observed that β-cells benefit from being cultured in a 3D environment, but in the 3D culture the β-cells often die …

Beginning Of Malignant Tumor Cells, Emily K. Shields

Biomedical Engineering Undergraduate Honors Theses

Despite advances in cancer treatments, cancer is still ranked the second leading cause of death. Cancers are started by cancer stem cells (CSCs). CSCs, also called tumor-initiating cells, are found in tumors and are responsible for the growth of tumors and the spread of cancer to other parts of the body. CSCs are very resistant, and cannot be killed by chemotherapy or radiation treatments. These cells can come from healthy stem cells. The environment surrounding the healthy stem cells and mature cells can cause mutations in the cell’s genetics, resulting in development of CSCs. The environment can also increase tumor …

Physiological Fluid Specific Agglomeration Patterns Diminish Gold Nanorod Photothermal Characteristics, Kristen K. Comfort, Jared W. Speltz, Bradley M. Stacy, Larry R. Dosser, Saber M. Hussain

Chemical and Materials Engineering Faculty Publications

Investigations into the use of gold nanorods (Au-NRs) for biological applications are growing exponentially due to their distinctive physicochemical properties, which make them advantageous over other nanomaterials. Au-NRs are particularly renowned for their plasmonic characteristics, which generate a robust photothermal response when stimulated with light at a wavelength matching their surface plasmon resonance. Numerous reports have explored this nanophotonic phenomenon for temperature driven therapies; however, to date there is a significant knowledge gap pertaining to the kinetic heating profile of Au-NRs within a controlled physiological setting. In the present study, the impact of environmental composition on Au-NR behavior and degree …

In Vivo Efficacy Of Chitosan/Interleukin-12 In Controlling Lung Metastasis In 4t1 Breast Cancer Model, Jimmy Vo

Biomedical Engineering Undergraduate Honors Theses

Cancer immunotherapy has emerged as a leading front in cancer treatment. In contrast to other treatment methods such as radiation and surgery, immunotherapy trains the patient's body to recognize and eliminate tumors, thus preventing reoccurrence of secondary tumors. IL-12 has been shown to display a potent anti-tumor immune response in mice; however, when clinical trials were conducted, it was shown to be toxic and in some cases fatal when administered systemically.1,2 Because of this, local delivery of IL-12 is under investigation. Our lab has shown that when paired with the polymer chitosan, local, intratumoral (i.t.) injections of IL-12 are retained …

Highly Sensitive Method For Detecting And Separating Pathogens Using Paramagnetic Particles And A Micro-Fluidic System, William Ryan

Biomedical Engineering Undergraduate Honors Theses

Water is one of the most important compounds on Earth. If a water supply is contaminated with a pathogen, it can have devastating results to an individual or a community. This research is directed at constructing an easily reproducible procedure that could increase the sensitivity of detecting and separating bacteria from the current limits of about 100 cells to 10-20 cells per sample with a ultimate goal of a single cell detection. Here, we report a micro-fluidic system to magnetically capture pathogenic bacteria in water followed by rapid impedance detection using Escherichia coli K-12 as a model bacterium. Paramagnetic beads …

Comparing Decellularized Muscle Tissue With An Engineered Muscle Biomaterial, Katelin Cherry

Biomedical Engineering Undergraduate Honors Theses

Decellularized tissues composed of extracellular matrix are commonly used for tissue transplantations but this method has many limitations. An alternative approach is to create an extracellular matrix by seeding degradable foams with cells, culturing these foams to allow extracellular matrix to be secreted from the cells, then washing away the degradable foam to collect the material that is produced. This study was interested in comparing decellularized skeletal muscle tissue to an engineered biomaterial that was seeded with skeletal muscle myoblast cells. Collagen content of decellularized tissue and engineered biomaterial were quantified using a hydroxyproline assay to compare the two samples. …

Rapid Detection And Quantification Of Mycobacterium Tuberculosis Using Single-Based Extension And Capillary Electrophoresis, Anh Vu

Biomedical Engineering Undergraduate Honors Theses

In 1993, the World Health Organization (WHO) has declared tuberculosis (TB) a global emergency. Since then, more than 30 million lives have been claimed by that world-wide epidemic. In 2011, 8.7 million people “felt ill” because of TB and not all TB cases were reported to clinicians. Therefore, it is important to accurately identify TB patients by developing a diagnostic method that is sensitive, fast, and cost-effective. However, conventional methods have not met those criteria because they either require lengthy procedures or may misdiagnose TB cases. Hence, the automated Xpert MTB/RIF, endorsed by WHO in 2010, was developed and so …

Glucose Biosensor Using Electrospun Mn2o3-Ag Nanofibers, Shan Huang

Master's Theses

The highly porous Mn₂O₃-Ag nanofibers were fabricated by a facile two-step procedure (electrospinning and calcination) and then employed as the immobilization matrix for glucose oxidase (GOD) to construct an amperometric glucose biosensor. A notable enhancement of direct electron transfer between GOD and the electrode is observed at the Mn₂O₃-Ag-GOD modified electrode with a fast electron transfer rate constant. The biosensor also shows fast response to glucose, high sensitivity (40.60 μA×mM^-1×cm^-2), low detection limit (1.73 µM at S/N=3), low K_m,app value and excellent selectivity. These results indicate that …

Intracellular Signaling Networks In The Immune Response: Pathways Activated By Interleukin-2 And-4 Receptors And Their Roles In T Cell Proliferation, Kristen K. Comfort

Chemical and Materials Engineering Faculty Publications

Cells sense and respond to chemical and physical stimuli through signal transduction pathways, which mediate cell proliferation, differentiation, migration, and survival. The cytokines interleukin-2 (IL-2) and interleukin-4 (IL-4) are key regulators of the adaptive immune system, particularly influencing the clonal expansion and differentiation of T cells. At least in culture, both synergistic and antagonistic effects of IL-2 and -4 co-stimulation have been reported; the antagonism, when observed, is thought to arise from the utilization of a common subunit shared by IL-2 and IL-4 receptors. We have sought to characterize IL-2 and IL-4 signaling at the level of intracellular pathways activated …