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Item Noise Reduction of Tunable Resistive Pulse Sensing for Improved Extracellular Vesicles Profiling in Cancer Detection(North Dakota State University, 2022) Ejjigu, NegaEVs have much potential as sensitive, novel biomarkers because they represent the status of their cells of origin and can be used to detect cancer earlier than alternative biomarkers. The size of EVs can be determined by tunable resistive pulse sensing (TRPS). However, TRPS is susceptible to environmental noise, including mechanical and electrical noise that limits detection precision. To overcome these noises, an external device was designed, guided by flow simulations, to reduce noises that interfere with TRPS measurements. Both mechanical and electrical environmental noise reductions were observed after using the shield. The study also validated the noise reduction function of the shield by quantifying EVs from different cell origins. This study demonstrates innovation in designing shielding enclosures using composite material to improve the sensitivity of emerging tunable resistive pulse technology to quantify EVs below 200 nm, which is challenging using traditional quantification methods.Item A Microstrip Transmission Line RF Biosensor: A Biosensing Device to Measure the Interaction Between Microliter Aqueous Solutions and Radio Frequencies(North Dakota State University, 2024) Godfrey, MaryBiosensors exploring the interaction between electromagnetic (EM) energy and aqueous solutions have long been an area of research interest. Previous research designs have employed various experimental setups, testing device structures, and frequency ranges to determine if property changes occur within the aqueous solutions under test after/during exposure to (EM) energy. Previous works have identified needs in the field, including smaller experimental device dimensions, a requirement of nanoliter to milliliter sampling volumes, and the ability to gather repeatable and sensitive measurements. Research Aim 1: The following dissertation questioned: Is it possible to design a sensor capable of measuring levels of interaction between RF energy and aqueous samples with reasonable reproducibility, sensitivity, and repeatability, all while being small in dimension, inexpensive to produce, and requiring microliter sample sizes? Research Aim 2: If the abovementioned sensor can be designed and verified, can it be used to measure the interaction levels between a broadband sweep of radiofrequencies and aqueous lambda DNA? In response to Research Aim 1, a millimeter-sized, microstrip transmission line biosensor with a microliter well operating on a broadband radio frequency range of 1.0-17.0 GHz was designed, simulated, and experimentally verified. Aqueous solutions, including deionized water, Tris-EDTA buffer, and lambda DNA, were loaded into the microliter well, and non-ionizing RF waves were transmitted down the transmission line. S-parameters were measured in sets to determine the interaction between the aqueous solution under test and the broadband radiofrequency sweep. Reproducibility and sensitivity were calculated for experimental data sets. Experimental data demonstrated 1) the RF biosensor’s ability to repeatably measure increasing concentrations of aqueous solutions, for example, lambda DNA diluted in Tris-EDTA buffer, and 2) a high measurement sensitivity, with the highest error value observed being 0.36%. Addressing Research Aim 2, increasing concentrations of lambda DNA diluted in Tris-EDTA buffer were experimentally measured, and reproducible trends were observed. Overall, the RF biosensor design was verified and determined to be a valid solution for measuring interaction levels between radiofrequencies and aqueous solutions of microliter quantities.Item A Narrative Review and Longitudinal Data Analysis Method to Evaluate the Association Between Head and Neck Cancer and Obstructive Sleep Apnea(North Dakota State University, 2022) Le, ToanThe pathophysiological mechanisms of obstructive sleep apnea (OSA) and head and neck cancers (HNCs) have not been fully investigated. Currently, investigating the relationship between HNCs and OSA is incomplete due to the restriction of histological, molecular, and clinical evidence. In this research, the first section reviews the common course of therapy in patients with HNCs and OSA, the causal relationship and association between HNCs and OSA, and the scope of statistical methods used to investigate the association between HNCs and OSA. According to the observation from the literature review, more rigorously designed studies with longitudinal data collection should be considered. To explore the potential in longitudinal data of HNCs patients with OSA, the second section concentrate on developing a framework that will determine the change over time of Apnea-Hypopnea index (AHI) in OSA patients and estimate the effect of treatment on the rate of change of AHI. Successfully address and confirm the relationship between HNCs treatment and OSA promise to support the management of cancer and OSA in adults.Item Optimizing Silk Protein Production Using an Engineering Approach(North Dakota State University, 2020) Meester, Kalleigh EmmalynThe acquisition of spider silk is a complex and costly process that restricts its availability. Increasing applications stemming from the biomedical and pharmaceutical sectors is driving the demand higher, necessitating the need for efficient large-scale production. This thesis investigates 1) recombinant protein expression systems, 2) major ampullate gland cell culture techniques for natural silk production, and 3) process optimization of recombinant silk protein expression. Using a process engineering analysis, the current E.coli system expression system was found to be a cost-effective and efficient technique for silk production. While a Box-Behnken predictive model was developed to optimize expression conditions based on small-scale E.coli expression data, it failed to translate to a larger-scale. Alternatively, the protein secreting cells that line the major ampullate silk gland were isolated and grown in conditions mimicking the native microenvironment, demonstrating a clear impact on growth of the cells and a potential new source of silk.Item Aortic Stenosis and the Path to Polymer Valves(North Dakota State University, 2023) Van Auken, KaitlynAll available heart valve medical devices on the market are made from biological tissues. The major drawback of using biological tissue is that it is prone to calcification, which is generally why the intervention was needed in the first place. There is also the limitation of lifetime of the device; because it is a biological material it is more prone to degradation, wear, and tear. This leaves room for improvement of the valve device, to move from a tissue valve to a polymer valve. There has been great promise with preliminary materials studies showing resistant to calcification and an almost doubling lifespan for a valve. However, none of this proposed polymer valves have gone through clinical testing and are in general still being bench- top studied. There is ample room for companies or research groups to explore medical device innovation relating to a polymer leaflet material.Item EVCD, Targeting Beta Sheet Richness of Tumor Derived Extracellular Vesicles for Pancreatic Cancer Screening(North Dakota State University, 2022) Elamurugan, SanthalingamPancreatic cancer is a deadly disease and a relatively uncommon form of cancer. However, it is projected to be the second leading cause of cancer deaths in the US by 2040. The 5-year survival rate of pancreatic cancer patients is 10 percent. Currently, there are no effective screening methods available. Extracellular vesicles are nanoparticles secreted by all cells and play versatile roles in human health. EVs can be used as a non-invasive biomarker for pancreatic cancer screening since they can be isolated from bodily fluids. Currently, single molecule biomarkers have been proposed for pancreatic cancer screening. They lack sensitivity and specificity. We studied the ‘collective attribute’ of protein secondary structures of EVs from two cancer (MiaPaCa2 and PANC-1) and one healthy cell line (HPNE). Protein secondary structures of EVs were studied using circular dichroism spectroscopy. We found that cancerous EVs contain more beta sheet rich proteins than non-cancerous EVs.Item Label-Free CD8+ T-cell Purification and Electroporation in Relation to CAR T-cell Therapy(North Dakota State University, 2020) Ringwelski, Beth AnneImmunotherapy is becoming recognized as a superior treatment for cancer. In recent years, chimeric antigen receptor (CAR) therapy is among the immunotherapies that has had growing success rates. CAR T-cell therapy takes patient’s T-cells and encodes them with a CAR expressing gene, which can then target their cancer cells. However, there are some dangers associated with this therapy. If a cancer cell is mistakenly transfected with the CAR molecule, it can become resistant to the therapy. Using the electric properties of the cells, we have created a technique that can purify the T-cells from the remaining cancer cells using microfluidics and dielectrophoresis (DEP). Then, to further improve the therapy, the sample is electroporated following being patterned using DEP forces, which transfects the cells without using viral vectors and provides longer CD19 expression.Item Wireless Wearable Device for the Acquisition of Bioelectrical Signals for Applications in Sleep Monitoring and Lucid Dream Induction(North Dakota State University, 2021) Nawrot, Andrew ShannonThe American Academy of Sleep Medicine (AASM) recommends at minimum seven hours of sleep per night, which means you would expect to spend a quarter of your lifetime asleep. Acute or chronic sleep deprivation can greatly impair quality of life, and lead to serious health problems. Many smart devices have begun to incorporate sleep monitoring functionalities; however, their claims and accuracy can leave users misguided or unsatisfied. Conversely, clinical sleep monitoring equipment is often too complex or impractical for consistent use. In order to address this gap, it is necessary to create a device that is wearable and non-obstructive, with the capabilities to record high-fidelity bioelectrical signals from the regions of interest. The Wearable Sleep Monitoring System (WSMS) device is a simple, lightweight, wearable device that records bioelectrical signals from the user in real-time, with the capability to communicate wirelessly with a paired smartphone application.Item Label Free Micro-RNA Biomarker Detection in Serum Samples for Potential Diagnosis Application at Point-of-Care Settings(North Dakota State University, 2020) Pokharel, RounakThe number of new cancer cases is projected to rise to 23.6 million by 2030 according to the National Cancer Institute. Obesity & cardiovascular diseases are among the leading causes of death worldwide according to recent reports. Biomarkers— any molecules found within a human body that can be used to monitor an individual's health — have been shown to play a significant role in the detection of cancer, obesity, and cardiovascular diseases. Recent studies have shown that in the diagnosis and screening of various human diseases, including cancer, obesity and cardiovascular diseases, circulating microRNAs (miRNAs) are important biomarkers. A crucial roadblock to using microRNA in screening applications is the lack of effective and low-cost microRNA detection. To address this issue, in this study, we have developed a viable method that combines the dielectrophoresis and electrical impedance. Results show this approach can measure very small concentrations of label-free microRNAs (1pM).Item On the Feasibility of Machine Learning Algorithms Towards Low-Cost Flow Cytometry(North Dakota State University, 2023-08-01) Vandal, NoahUtilization low cost, scalable architectures for detection of specific cells for both mass flow and minute incidence analysis is something that is attractive for the clinical researcher, in order to expand access to otherwise costly devices. We demonstrate the use of a low-cost microfluidics device that performs detection of beads and cells, both for cell counting and for discrete cell type identification. This was accomplished using polymer technology via implementation of polydimethylsiloxane microfluidics, which were created by using a 3-D printed mold, and machine learning technologies with algorithms that can inference and track analyte particles within the microfluidic of interest. Our demonstration of our microfluidics device is proof that creating low cost instruments for analyte detection using current machine learning models and hardware is possible. We foresee the scalability of this design to be immense, in terms of throughput rate, inexpensiveness of product, and multiple different parameters and classes that can be searched for.