Biomedical Engineering and Bioengineering Commons^™

Study Of Porosity Of Gelatin-Alginate Hydrogels To Model Brain Matter For Studying Traumatic Brain Injuries, Apolline Vincent

Honors Scholar Theses

Traumatic brain injuries (TBIs) affect brain tissue and neuronal signaling, leading to many side effects including death. Research on TBIs is limited by the lack of accurate brain matter models to study the physiological and cellular reaction. Alginate-gelatin hydrogels have been designed and modified to mimic the mechanical properties of the brain to act as an accurate in vitro model. This Honors thesis aims to verify the porous microstructure of gelatin-alginate hydrogels through Scanning Electron Microscopy (SEM) to understand how gelatin and alginate affect the microstructure. I measured the pore sizes of each hydrogel using ImageJ, compared the average pore …

Drug-Facilitated Sexual Assault At The University Of Arkansas, Barrett Weidman

Chemical Engineering Undergraduate Honors Theses

This work was written to fulfill two main purposes. First, to help survivors of Drug-Facilitated Sexual Assault (DFSA) process their experience by compiling the toxicological, pharmacological, and distribution of the three most used date-rape drugs. Second, to gauge the knowledge and interest of University of Arkansas students regarding drug impairments, sexual assault education, and bystander intervention training. A survey was conducted for the latter and revealed that 91.6% of students believe the University’s existing sexual assault prevention education and bystander intervention training have room for improvement. Also, 37.1% of students who have received this education report that the programming does …

Release Kinetics Of Metronidazole From 3d Printed Silicone Scaffolds., Sydney E. Herold

Electronic Theses and Dissertations

Sustained local administration of active agents has been proposed to cure bacterial vaginosis in the female reproductive tract and restore the resident bacterial fauna. Bioprinting has shown promise for the development of systems for local agent delivery. In contrast to oral ingestion, agent release kinetics can be fine-tuned by bioprinting specialized scaffold designs tailored for particular treatments while enhancing dosage effectiveness via localized sustained release. It has been challenging to establish scaffold properties for sustained release as a function of fabrication parameters. Towards this goal, we evaluate 3D printed scaffold formulation and feasibility to sustain release of metronidazole, a representative …

Nonviral Approaches For Delivery Of Crispr-Cas9 Into Hepatocytes For Treatment Of Inherited Metabolic Disease, Tanner R. Rathbone

All Dissertations

Inherited metabolic diseases (IMDs) of the liver have a collective occurrence of about 1 in 800 births. Current therapies for IMDs of the liver are limited, and the only curative option for patients is orthotopic liver transplantation. Due to shortages of organ donors, immunosuppression following the transplantation, and mortality risks associated with the procedure, alternative treatment options are necessary for curing IMDs of the liver. Therapeutic gene editing has been proposed as a potential strategy for treating IMDs of the liver. Adeno-associated viral vectors (AAVs) are the most widely used delivery method for liver-targeted gene therapies. Although widely used for …

Development And Application Of 3d Kinematic Methodologies For Biomechanical Modelling In Adaptive Sports And Rehabilitation, Anne Marie Severyn

All Dissertations

Biomechanical analysis is widely used to assess human movement sciences, specifically using three-dimensional motion capture modelling. There are unprecedented opportunities to increase quantitative knowledge of rehabilitation and recreation for disadvantaged population groups. Specifically, 3D models and movement profiles for human gait analysis were generated with emphasis on post-stroke patients, with direct model translation to analyze equivalent measurements while horseback riding in use of the alternative form of rehabilitation, equine assisted activities and therapies (EAAT) or hippotherapy (HPOT). Significant improvements in gait symmetry and velocity were found within an inpatient rehabilitation setting for patients following a stroke, and the developed movement …

Single Asperity Fretting Corrosion Of Traditional And Additively Manufactured Metallic Biomaterials: Quantitative Analysis From Acetabular Tapers To Micron And Nanometer Scale Tribocorrosion, Annsley Mace

All Dissertations

Mechanically assisted crevice corrosion (MACC) of metallic biomaterials continues to be a significant degradation mode. This is, in part, due to a lack of understanding of fundamental micron- and sub-micron scale mechanisms of metal degradation in biological environments. Metal-metal (or metal-hard) load bearing surfaces of hip arthroplasties are subjected to fretting crevice corrosion (FCC, one form of MACC). Current work in tribocorrosion involves large contact area tests with multiple asperities, with a distribution of load and wear that changes over time. A more systematic and controlled study of the FCC micro- and nanomechanics is needed.

Therefore, the goal of this …

Neural Correlates Of Multisensory Integration For Feedback Stabilization Of The Wrist, Aaron J. Suminski, Raymond C. Doudlah, Robert A. Scheidt

Biomedical Engineering Faculty Research and Publications

Robust control of action relies on the ability to perceive, integrate, and act on information from multiple sensory modalities including vision and proprioception. How does the brain combine sensory information to regulate ongoing mechanical interactions between the body and its physical environment? Some behavioral studies suggest that the rules governing multisensory integration for action may differ from the maximum likelihood estimation rules that appear to govern multisensory integration for many perceptual tasks. We used functional magnetic resonance (MR) imaging techniques, a MR-compatible robot, and a multisensory feedback control task to test that hypothesis by investigating how neural mechanisms involved in …

Insole Fall Prevention Device, Nick M. Hughes, Andrew M. Slaboda

Biomedical Engineering

Falls among the aging population occur every single day, with 1 in every 5 resulting in some injury and 300,000 hospitalized every year with a hip fracture [1]. The most popular and effective way to mitigate these falls is through physical therapist intervention. However, with the increased popularity in telerehab, many patients at risk for falls cannot accurately convey their gait tendencies to their physical therapists from the comfort of their home or while not in direct contact with the PT. A device like an insole, implanted with force sensors, which measures different parts of a patient’s foot, could convey …

A Modeling Platform To Predict Cancer Survival And Therapy Outcomes Using Tumor Tissue Derived Metabolomics Data., Hunter Allan Miller

Electronic Theses and Dissertations

Cancer is a complex and broad disease that is challenging to treat, partially due to the vast molecular heterogeneity among patients even within the same subtype. Currently, no reliable method exists to determine which potential first-line therapy would be most effective for a specific patient, as randomized clinical trials have concluded that no single regimen may be significantly more effective than others. One ongoing challenge in the field of oncology is the search for personalization of cancer treatment based on patient data. With an interdisciplinary approach, we show that tumor-tissue derived metabolomics data is capable of predicting clinical response to …

Characterization Of Fundamental Parameters That Modulate Acoustofluidic-Mediated Molecular Delivery To Cells., Connor Sterling Centner

Electronic Theses and Dissertations

Cell-based therapies represent the latest biotechnological revolution in medicine, but significant limitations exist in non-viral intracellular delivery techniques during manufacturing of cell therapies. To address these limitations, a novel acoustofluidic device was developed to deliver ultrasound waves into a flow chamber for rapid molecular delivery to human cells. Our acoustofluidic device delivers biomolecules by inducing expansion and collapse of exogenous gas-filled microbubbles (“cavitation”), which enhances molecular delivery to nearby cells. Experimental studies were conducted to characterize key parameters that influence acoustofluidic-mediated molecular delivery to human cells. A clinical ultrasound transducer was generally utilized with varying cationic microbubble concentrations. Intracellular delivery …

Machine Learning Analysis Of Acoustic Attenuation Measurements For Cellular Characterization., John T. Moore

Electronic Theses and Dissertations

T-cell therapies have been gaining popularity in recent years due to their cancer fighting potential. With remission rates improving in this field of immunotherapy, the demand for T-cell therapies has also increased; however, the cell processing techniques for these therapeutic products have yet to rise to the level of demand. The manufacturing process takes too long and a significant amount of processed cell batches can fail to meet safety requirements. These limitations of cell processing can be detrimental to patients seeking T-cell therapies. While current products have improved the time it takes to manufacture these therapeutic products, there is still …

Fabrication And Characterization Of Lactobacillus Crispatus Containing Bioprints For Bacterial Vaginosis Application., Anthony J. Kyser

Electronic Theses and Dissertations

Bacterial vaginosis (BV) is a condition in which healthy lactobacilli are replaced by an overabundance of pathogenic bacteria in the female reproductive tract. Current antibiotic treatments often fail to “cure” infection, resulting in recurrence in more than 50% of women, 6 months post-treatment. Recently, probiotics have demonstrated promise to restore vaginal health; however, as with other active agents, delivery requires once-to-twice daily administration. Recently, three-dimensional (3D)-bioprinting has enabled the fabrication of well-defined cell-laden architectures with tunable agent release, thereby presenting a novel approach with which to deliver probiotics. One promising bioink, gelatin alginate, was selected for study, due to its …

Acoustofluidic Delivery Of Gene Editing Compounds For Improved Immunotherapy Processing., Riyakumari K. Patel

Electronic Theses and Dissertations

Cell-based immunotherapies are a new generation of “living-drug” treatments for cancer and other diseases. Chimeric antigen receptor (CAR) T-cell cancer therapy has shown promising results in lymphoma and B-cell malignancies. Currently, there are six FDA-approved CAR-T drugs on the market, and all of them use viral transfection for reprogramming. While viral transfection is effective, there are safety concerns due to inconsistent transfection that limit the use of CAR-T therapy. Current non-viral transfection techniques generally have lower transfection efficiency than viral transfection. Additionally, these techniques can be toxic, time-consuming, non-transportable, and expensive. To address these limitations, a novel 3D printed acoustofluidic …

Diffusive Dynamics Of Biological Macromolecules In The Cytoplasm Of Live Bacteria, Asmaa Ali Sadoon

Graduate Theses and Dissertations

Bacteria are small organisms that play important roles in our bodies and in maintaining our surrounding environment. However, bacterial infections are considered as one of the health diseases that threatens the lives of humans. Resistance of bacteria to antibiotics has made treating bacterial infections more challenging. With the emergence of many developed optical techniques, it has become possible to study various biological mechanisms of molecules inside these small organisms with high resolution and precise localization. In this research, single particle tracking photoactivation localization microscopy (sptPALM) technique was used to investigate the dynamics of fluorescent histonelike nucleoid-structuring proteins (H-NS) in live …

Diffusive Dynamics Of Biological Macromolecules In The Cytoplasm Of Live Bacteria, Asmaa Sadoon

Graduate Theses and Dissertations

Bacteria are small organisms that play important roles in our bodies and in maintaining our surrounding environment. However, bacterial infections are considered as one of the health diseases that threatens the lives of humans. Resistance of bacteria to antibiotics has made treating bacterial infections more challenging. With the emergence of many developed optical techniques, it has become possible to study various biological mechanisms of molecules inside these small organisms with high resolution and precise localization. In this research, single particle tracking photoactivation localization microscopy (sptPALM) technique was used to investigate the dynamics of fluorescent histonelike nucleoid-structuring proteins (H-NS) in live …

Development Of A Long-Read Sequencing Protocol To Assess The Precision And Efficacy Of Gene Editing For Duchenne Muscular Dystrophy, Landon Andrew Burcham

Graduate Theses and Dissertations

This work establishes a method for assessing on-target precision due to CRISPR-Cas9 gene editing, especially within the context of exon skipping therapy for Duchenne Muscular Dystrophy. The proposed method utilizes an Oxford nanopore long-read sequencing approach to sequence amplified regions of DNA that have been edited using CRISPR-Cas9. NIH3T3 and C2C12 cell lines were treated with a dual-guide CRISPR-Cas9 system, that targets and deletes exon 23 from the DMD gene in mouse samples. Deletion PCR revealed deletion of exon 23 in both DNA and cDNA samples. Additionally, sequencing using Oxford Nanopore revealed targeted exon 23 deletion as the most prevalent …

Cyanobacterial And Microcystin Response To Nutrient Additions At Lake Fayetteville Throughout The 2021 Growing Season, Lillie Haddock

Graduate Theses and Dissertations

Harmful Algal Blooms (HABs) are becoming a global concern due to their increasing distribution, frequency, intensity, and the occurrence of toxins. While it is known that eutrophication influences algal blooms, there is less known about what triggers these HABs to produce toxins, especially microcystin. In this study, we conducted 21 community bioassays at Lake Fayetteville, a hypereutrophic reservoir in Fayetteville, Arkansas, from April-November 2021 to examine how the addition of phosphorous and nitrogen influence cyanobacteria concentrations, microcystin concentrations, and microcystin toxin production. These experiments included a control, nitrogen (1.0 mg/L as KNO3), low phosphorus (0.025 mg/L as K2HPO4), high phosphorus …

The Effects Of Metronomic And Maximum-Tolerated Dose Chemotherapy In Colorectal Cancer Angiogenesis: A Combined Approach Using Endoscopic Diffuse Reflectance Spectroscopy And Mrna Expression, Ariel Isaac Mundo Ortiz

Graduate Theses and Dissertations

Colorectal cancer (CRC) continues to be one of the most incident and deadliest types of cancer worldwide. Chemotherapy has proven effective to reduce tumor burden for CRC patients, but there are several disadvantages associated with the use of mainstay maximtolerated dose (MTD) chemotherapeutic strategies. Metronomic chemotherapy (MET) has been developed as an alternative that addresses the shortcomings of maximum-tolerated dose chemotherapy but so far its effectiveness as a neoadjuvant strategy for CRC has not been explored.

This dissertation uses a combined optics and molecular biology approach (using diffuse reflectance spectroscopy and mRNA expression) to study the changes in angiogenesis and …

Investigating Arrhythmia Potential In Cardiac Myocytes In Presence Of Long Qt Syndrome, Victoria Lin Lam

Biomedical Engineering Theses & Dissertations

Long QT Syndrome (LQTS) is an increasingly studied condition that leads to potentially fatal heart rhythm disorders, called arrhythmias, and sudden cardiac death. The alterations in the electrocardiograms (ECGs) seen in LQTS patients is caused by mutations to genes related to ion channels in cardiac cells. Computational modeling allows the mechanistic study of these ion channel mutations in LQTS by providing quantitative predictors of cardiac behavior in human and rabbit heart models. This work hypothesizes that the repolarization reserve in cardiac Purkinje cells (PC), that form the cardiac conduction system, is lower than that of ventricular myocytes (VM), resulting in …

Effects Of Orthopedic Implant And Host Bone Properties On Stress-Shielding Induced Osteopenia, Scott Jason Jan Baskerville

Theses and Dissertations

Stress shielding is a term commonly used in literature to describe a bone density reducing phenomenon which occurs due to long-term exposure of bone tissue to sub-homeostatic levels of mechanical stimuli. A number of mechanobiological models ranging in complexity and purpose have been developed with the general overall intent of predicting bone remodeling behavior under a set of prescribed conditions. A previously developed heuristic model is expanded in the present work through model calibration with physiological data and the development of a reduced bone-implant-construct (BIC) mechanical model configurable for patient factors such as age, gender, and associated bone properties. The …

Cellular Migration As A Function Of Magnetic Field Intervention, Amy Marie Vecheck

Theses and Dissertations

This work aims to assess cellular migration in three-dimensional structures as a function of Zeeman resonance. By using Zeeman resonance to initialize intersystem crossing of electrons, also known as the Radical Pair Mechanism, bioenergetics processes would be modulated. Processes such as oxygen consumption rate and extracellular acidification rate are indicative of cellular respiration and glycolysis and can be altered based on the orientation of the magnetic field applied: parallel and perpendicular, respectively. This study focused on the parallel orientation and looked to used Zeeman resonance to increase flavin adenosine dinucleotide, which results in preventing the breakdown of F-actin. Cellular viability …

Computer Vision And Machine Learning Applications In Cellular Images And Clinical Data, Guochang Ye

Theses and Dissertations

With the progressive development of artificial intelligence (AI), automated analysis has been explored for substituting tedious manual methods in cellular image analysis. Additionally, medical information not included in the conventional statistical methods is now being reconsidered with AI-based personalized medicine. The adaptivity and flexibility of AI ensure its efficiency and accuracy. In this work, computer vision and machine learning (ML) methods under the scope of AI are explicitly investigated and applied to cellular images and clinical data for cytological analysis and to provide diagnosis-based assistance/predictions. Firstly, novel computer vision algorithms achieve cell detection and differentiation estimation on phase-contact microscopic images …

Influence Of Mouthguard Design On Sports Performance And Injury Prevention, Mohammad Ahmed

Theses and Dissertations

Contact sports are associated with some invisible injuries after the incident when symptoms do not appear until weeks after. This can be dangerous as players may continue to engage in the sport and risk further injury. Athletic mouthguards are used to reduce the risk of injury, but there is insufficient data to quantify the effectiveness of mouthguard design on sports performance and injury prevention. In this work, the thickness and material selection of the mouthguard design were characterized in terms of airway resistance, electromyography muscle activation, and energy absorption. First, the effect of thickness on the condyle and temporal bone …

Comparison Of Cone Mosaic Metrics From Images Acquired With The Spectralis High Magnification Module And Adaptive Optics Scanning Light Ophthalmoscopy, Niamh Wynne, Heather Heitkotter, Erica N. Woertz, Robert F. Cooper, Joseph Carroll

Biomedical Engineering Faculty Research and Publications

Purpose: To compare cone mosaic metrics derived from adaptive optics scanning light ophthalmoscopy (AOSLO) images with those derived from Heidelberg Engineering SPECTRALIS High Magnification Module (HMM) images.

Methods: Participants with contiguous cone mosaics had HMM imaging performed at locations superior and temporal to the fovea. These images were registered and averaged offline and then aligned to split-detection AOSLO images; 200 × 200-µm regions of interest were extracted from both modalities. Cones were semi-automatically identified by two graders to provide estimates of cone density and spacing.

Results: Thirty participants with contiguous cone mosaics were imaged (10 males, 20 females; age range, …

Training The Responsible Conduct Of Research And Design, Jay R. Goldberg

Biomedical Engineering Faculty Research and Publications

Students Supported by grants from the National Institutes of Health (NIH) are required to complete training in the responsible conduct of research (RCR). This training includes topics such as authorship, handling of data, reporting of results, maintaining confidentiality, and other topics related to the ethical and responsible conduct of research. It prepares students who are supported by NIH research grants for careers involving research.

5-Axis Milling For Micro-Machining Of Implantable Flow Sensor, Devin Kot-Thompson

Honors Scholar Theses

5 axis milling is a manufacturing process utilizing CNC technology. It has been widely supported as an effective tool for micro machining throughout multiple industries. In medical manufacturing specifically, there is a large demand for high accuracy at the microscale level as the geometries of medical devices are often highly complex. 5-axis milling offers the means to develop such complex features including curved faces and steep walls. This thesis covers the conversion of a generic 3-axis milling machine into a 5-axis machine. Through testing, the modified device effectively demonstrated its ability to run 5-axis tool paths required for complex designs. …

Basketball Shooting Performance Is Maximized By Individual-Specific Optimal Release Strategies, Nathan Slegers

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

This study investigated the relationship between optimal basketball release angles and individual release distributions and whether individuals seek their optimal or minimum velocity release strategy. Sixteen male basketball players (height 183 ± 9 cm, age 22.6 ± 7 years) were recorded shooting 75 three-point shots. Ball release angle and velocity estimates were used in a nonparametric kernel density estimator (KDE) to identify individual-specific release distributions and optimal release angles. Optimal releases varied among individuals and were 4.3 ± 2.1° higher than minimum velocity releases. Mean release angles were 3.9° higher than the minimum velocity angle (p < 0.001) and only 0.4° below the optimal (p = 0.5). …

Evaluating The Use Of Nintendo Labo As A Rehabilitation Tool, Jacob Colwell, Logan Suiter, Amanda Wells

ONU Student Research Colloquium

Serious gaming is the practice of using video games, either commercial or specifically designed, for physical rehabilitation. Serious games have emerged in the last decade as a way to increase patient involvement in rehabilitation, increase the likelihood of patients continuing treatment after progress stalls, and generally increase mental health during treatment. However, the current literature has not kept pace with the evolution of technology and therefore the use of next-generation consoles for serious gaming is underdeveloped.

The Nintendo Switch could provide new avenues for serious gaming because of the advanced sensing ability of its controllers (Joy-Cons) and the engaging ways …

Nanoparticulate Carriers For Drug Delivery, Samantha Lokelani Crossen, Tarun Goswami

Biomedical, Industrial & Human Factors Engineering Faculty Publications

Drug delivery with nanoparticulate carriers is a new and upcoming research area that is making major changes within the pharmaceutical industry. Nanoparticulate carriers are discussed, particularly, engineered nanoparticulate carriers used as drug delivery systems for targeted delivery. Nanoparticulate carriers that are used for drug delivery systems include polymers, micelles, dendrimers, liposomes, ceramics, metals, and various forms of biological materials. The properties of these nanoparticulate carriers are very advantageous for targeted drug delivery and result in efficient drug accumulation at the targeted area of interest, reduced drug toxicity, reduced systemic side effects, and more efficient use of the drug overall. Nanoparticlulate …

Bio-Ionic Liquid Functionalized Hydrogels Towards Smart Tissue Regeneration, Vaishali Krishnadoss

Theses and Dissertations

A blend of scaffolds, biologically active molecules, and cells are required to assemble functional constructs to repair and regenerate damaged tissue or organ via tissue engineering. The scaffold supports cell growth and proliferation and acts as a medium for diverse cellular activities. Even though hydrogel's high-water content and flexible nature make it a pronounced applicant as a scaffold, they exhibit significant technical limitations such as the absence of cell-binding motifs, lack of oxygen, conductivity, adhesive properties, growth of cells in a 3-dimensional (3D) microenvironment. In this thesis, a novel material platform is evaluated and studied to address the concerns mentioned …