Biomedical Engineering and Bioengineering Commons^™

Intravascular Ultrasound Is More Accurate Than Angiography In Arteriovenous Vascular Access Lesions, James W. Decker, Dima Banihani, Curtis Honshideler, Saran Lotfollahzadeh, David Jasen Wu Wong, Alik Farber, Jeffrey J. Siracuse, Najia Idrees, Laura Dember, Mohammad Bader, Suvranu Ganguli, Vijaya Kolachalama, Tarek Shazly

Faculty Publications

Background:

Conventional angiography remains the standard diagnostic modality for arteriovenous (AV) access dysfunction in hemodialysis patients, but its geometric accuracy is limited. Intravascular ultrasound (IVUS) offers superior lesion detection, yet its absolute measurement accuracy remains uncertain. Using three-dimensional (3D) printed vascular conduits as reference standards, we assessed the accuracy of IVUS versus angiography, hypothesizing that complex conduit geometry, quantified by Gaussian curvature, would exacerbate angiographic error.

Methods

Clinically relevant AV access geometries were modeled with computer-aided design (CAD) and fabricated using 3D printing. Lumen diameters were measured by contrast angiography and IVUS and compared with CAD dimensions. Conduit geometry was …

Structural And Mechanical Properties Facilitate Shock Wave Damping By Helmet-Like Orbital Hoods In Snapping Shrimp, Mia Kazel, Rebekah E. Cammack, Alexandra C.N. Kingston, Ahmed A. Alshareef, Tarek Shazly, Daniel Isaac Speiser

Faculty Publications

Snapping shrimp damp the shock waves they produce and use as weapons with a helmet-like structure termed the orbital hood. Here, we ask how structural and material properties contribute to shock wave damping by orbital hoods in Alpheus heterochaelis. Using tensile mechanical testing, we find orbital hoods are approximately half as stiff as carapace and have twice the capacity for viscous energy dissipation. Microstructural features probably contribute to tissue-specific mechanical properties: the endocuticles of orbital hoods have almost twice as many lamellae as those of carapaces despite being half as thick, suggesting a mechanism for enhanced material mobility underlying …

Polystyrene Nanoplastics As Pfas Carriers And Their Interactions With Zwitterionic Phospholipid Membranes, Jiahuiyu Fang, Tongxuan Qiao, Pranab Sarker, Xiaoxue Qin, Size Zheng, Mark J. Uline, Tao Wei

Faculty Publications

The co-occurrence of per- and polyfluoroalkyl substances (PFAS) and nanoplastics (NPs) poses a synergistic threat to environmental and human health, yet the molecular mechanisms governing PFAS–NP complexation and membrane interactions remain unclear. Using atomistic molecular dynamics simulations, we investigated the adsorption of neutral polytetrafluoroethylene (PTFE) and anionic perfluorinated compounds (perfluorooctanoic acid, PFOA, and perfluorooctanesulfonic acid, PFOS) on polystyrene NPs (3.1 and 6.7 nm) and their interactions with 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) membranes. Polystyrene NPs act as carriers, transporting PFAS molecules to the lipid/water interface, where PFAS attachment modifies NP interfacial behavior. PFAS adsorption on the NP surface is driven by …

Detecting Polar Ring Galaxies Via Deep Learning, Fawad Kirmani, Anathavishnu S. Unnii, Varsha P. Kulkarni, Kyle Lackey, John R. Rose

Faculty Publications

Polar ring galaxies (PRGs) are peculiar galaxies that show a ring of stars, gas, and dust oriented roughly over the poles of the central ‘host’ galaxy (i.e. roughly orthogonal to the disc of the host galaxy). The formation models for these rings involve mergers or tidal interactions of the host galaxy with another galaxy. Although the identified PRGs look different from each other, they all have a ring that is not in the same plane as the disc of the host galaxy. Unlike in galaxies such as our Milky Way, where stars form in spiral arms, the rings exemplify an …

Gut Microbiome Dynamics In Heart Failure And The Therapeutic Potential Of Nmeg-Cgrp, Kamryn Michael Gleason

Theses and Dissertations

Heart failure (HF) is increasingly recognized as a multisystem disease often linked to gut dysbiosis; however, its specific effects on gut microbial composition remain poorly understood. This study examined long-term changes in the gut microbiome in a murine HF model induced by transverse aortic constriction (TAC) and evaluated the effects of NMEG-CGRP. TAC mimics pressure overload-induced cardiac dysfunction, replicating key features of HF. CGRP, a neuropeptide with vasodilatory and cardioprotective effects, shows potential as a therapy for HF but is limited by rapid degradation. A stabilized analog, NMEG-CGRP, was used to assess its impact on cardiac and gastrointestinal health. Mice …

Multiscale Geometric Analysis In Endovascular Therapies: Ex Vivo, In Silico Approaches, Dima Hussein Ali Bani Hani

Theses and Dissertations

In this work, we address a persistent global challenge of vascular disease, specifically peripheral artery disease (PAD), and arteriovenous fistula (AVF) complications in patients with end-stage kidney disease (ESKD). The important role of vascular geometry in disease intervention plans and the development of endovascular therapeutic strategies (e.g., Drug-coated balloon (DCBs)) is critical in addressing these challenges.

This study evaluates the feasibility of co-delivery of paclitaxel (PTX) and valsartan (VAL) using urea-based coatings in DCB, analyzes the coating morphology and microstructural changes to improve therapeutic results. A computational finite element model was developed to complement experimental work, simulate tissue-coating interactions, compute …

Characterizing The Relationships Between Cranial Geometry, Brain Morphometry, And Brain Mechanical Properties Using Mr Imaging And Elastography, Jessica Restivo

Theses and Dissertations

Traumatic brain injury (TBI) is a global health concern, with over 69 million cases annually. TBI risk depends on subject-specific neuroanatomical variation, yet research often only considers generic finite element (FE) models, based on the geometry and material composition of a 50th percentile male head. Although highly accurate, subject-specific models require expensive magnetic resonance (MR) imaging, elastography, and time-consuming computational resources. There is a need to create subject-specific TBI models that account for subject-specific variations, without neuroimaging. This study aims to create mathematical models to predict brain morphometry (dimensions, volume) [Objective 1] and mechanical properties (shear stiffness, damping ratio, octahedral …

Adsorption And Electron Transfer Of Metal-Reducing Decaheme Cytochrome Protein Mtrf On Iron Oxide Nanoparticle Surfaces, Jiahuiyu Fang, Pranab Sarker, Xiaoxue Qin, Shuting Zhang, Size Zheng, Tao Wei

Faculty Publications

Dissimilatory metal-reducing bacteria (DMRB) transfer electrons to extracellular metal oxides via a multiheme cytochrome network. Coupling DMRB with iron oxide nanoparticles (NPs) enables continuous redox processes for various applications such as bioremediation and bioenergy. The conformation of the terminal decaheme cytochrome MtrF on the surface critically influences electron transfer (ET) efficiency. In this work, we used molecular dynamics simulations and master equations to study MtrF adsorption on 3.6 and 6.0 nm α-Fe2O3 NPs and its steady-state ET in water. Our study shows that the heme cofactors can have strong electrostatic interactions with iron oxide NP surfaces, promoting protein adsorption and …

Average Biomechanical Responses Of The Human Brain Grouped By Age And Sex, Ahmed A. Alshareef, Aaron Carass, Yaun-Chiao Lu, Joy Mojumder, Alexa M. Diano, Olivia M. Bailey, Ruth J. Okamoto, Dzung L. Pham, Jerry L. Prince, Philip V. Bayly, Curtis L. Johnson

Faculty Publications

Traumatic brain injuries (TBIs) occur from rapid head motion that results in brain deformation. Computational models are typically used to estimate brain deformation to predict risk of injury and evaluate the effectiveness of safety countermeasures. The accuracy of these models relies on validation to experimental brain deformation data. In this study, we create the first group-average biomechanical responses of the brain, including structure, material properties, and deformation response, by age and sex from 157 subjects. Subjects were sorted intro three age groups—young, mid-age, and older—and by sex to create group-average neuroanatomy, material properties, and brain deformation response to non-injurious loading …

Endothelial Dysfunction Promotes Age-Related Reorganization Of Collagen Fibers And Alters Aortic Biomechanics In Mice, Liya Du, Jeffrey Rodgers, Nazli Gharraee, Olivia Gary, Tarek Shazly, John F. Eberth, Susan M. Lessner

Faculty Publications

Endothelial dysfunction, defined as a reduction in the bioavailability of nitric oxide (NO), is a risk factor for the occurrence and progression of various vascular diseases. This study investigates the effect of endothelial dysfunction on age-related changes in aortic extracellular matrix (ECM) microstructure and the relationship between microstructural adaptation and the mechanical response. Here, we used groups of NOS3 knockout (KO), NOS3 heterozygotes (Het), and wild-type (WT) B6 mice (controls) to study changes in hemodynamic parameters, collagen fiber organization, and both active and passive aortic mechanics using biaxial pressure myography over a time course from 1.5 to 12 mo. Our …

Endothelial Dysfunction Promotes Age-Related Reorganization Of Collagen Fibers And Alters Aortic Biomechanics In Mice, Liya Du, Jeffrey Rodgers, Nazli Gharraee, Olivia Gary, Tarek Shazly, John F. Eberth, Susan M. Lessner

Faculty Publications

Endothelial dysfunction, defined as a reduction in the bioavailability of nitric oxide (NO), is a risk factor for the occurrence and progression of various vascular diseases. This study investigates the effect of endothelial dysfunction on age-related changes in aortic extracellular matrix (ECM) microstructure and the relationship between microstructural adaptation and the mechanical response. Here, we used groups of NOS3 knockout (KO), NOS3 heterozygotes (Het), and wild-type (WT) B6 mice (controls) to study changes in hemodynamic parameters, collagen fiber organization, and both active and passive aortic mechanics using biaxial pressure myography over a time course from 1.5 to 12 mo. Our …

Shear-Thinning Hydrogel For Delayed Delivery Of A Small Molecule Metalloproteinase Inhibitor Attenuates Myocardial Infarction Remodeling, Joshua E. Mealy, William M. Torres, Lisa A. Freeburg, Shayne C. Barlow, Alison A. Whalen, Chima V. Maduka, Tarek Shazly, Jason A. Burdick, Francis G. Spinale

Faculty Publications

No abstract provided.

Chemical Damping Of The Motion Of A Piston: Irreversibilities Arising From Nonequilibrium Conditions On The Chemical Potential, David S. Corti, Mark J. Uline

Faculty Publications

We revisit the thermodynamic analysis of an isothermal ideal gas mixture enclosed within a cylinder and separated from the surrounding atmosphere by a movable and frictionless piston. When equilibrium conditions based on the chemical potentials of one or more species in the mixture are not satisfied at all times, which occurs for example for a chemical reaction with finite and non-zero reaction rates in the forward and reverse directions and for mass transfer of one species across a permeable membrane occurring at a finite and non-zero rate, an irreversibility is necessarily introduced into the system with a resulting increase in …

Associations Between Social Determinants Of Health And Mental Health Disorders Among U.S. Population: A Cross-Sectional Study, S. Tanarsuwongkul

Faculty Publications

Aims

The impact of social determinants of health (SDOH) on mental health is increasingly realized. A comprehensive study examining the associations of SDOH with mental health disorders has yet to be accomplished. This study evaluated the associations between five domains of SDOH and the SDOH summary score and mental health disorders in the United States.

Methods

We analyzed data from a diverse group of participants enrolled in the All of Us research programme, a research programme to gather data from one million people living in the United States, in a cross-sectional design. The primary exposure was SDOH based on Healthy …

Single-Molecule Profiling Of Per- And Polyfluoroalkyl Substances By Cyclodextrin Mediated Host-Guest Interactions Within A Biological Nanopore, Xiaojun Wei, Aditya Choudhary, Leon Y. Wang, Lixing Yang, Mark J. Uline, Mario Tagliazucchi, Qian Wang, Dmitry Bedrov, Chang Liu

Faculty Publications

Biological nanopores are increasingly used in molecular sensing due to their single-molecule sensitivity. The detection of per- and polyfluoroalkyl substances (PFAS) like perfluorooctanoic acid and perfluorooctane sulfonic acid is critical due to their environmental prevalence and toxicity. Here, we investigate selective interactions between PFAS and four cyclodextrin (CD) variants (α-, β-, γ-, and 2-hydroxypropyl-γ-CD) within an α-hemolysin nanopore. We demonstrate that PFAS molecules can be electrochemically sensed by interacting with a γ-CD in a nanopore. Using HP-γ-CDs with increased steric resistance, we can identify homologs of the perfluoroalkyl carboxylic acid and the perfluoroalkyl sulfonic acid families and detect common PFAS …

Effect Of Storage Time And Temperature On Aggregation Of Alzheimer's Disease Amyloid-Β Protein, Amy Veihdeffer

Theses and Dissertations

Amyloid-β protein (Aβ) is widely studied due to its key role in Alzheimer’s disease (AD) pathology. One characteristic of patients suffering from AD is the deposition of amyloid plaques comprised of Aβ aggregates, which are associated with synapse damage. Thus, studying Aβ aggregation and aggregation inhibition may provide pathological and therapeutic insights. Aggregation of Aβ is a nucleation dependent process that may be influenced by the presence of pre-formed Aβ aggregate seeds that can facilitate formation of protein aggregates. These seeds may appear during preparation or storage of monomer, posing impact on experiments that study the aggregation process and the …

Vascular Calcification In A Mouse Model Of Chronic Kidney Disease And In Human Peripheral Arterial Disease, Breanna Pederson

Theses and Dissertations

Vascular calcification is a process in which calcium and phosphate crystallize to form hydroxyapatite in the extracellular matrix of blood vessels. There are two forms of arterial calcification: intimal and medial, which occur via different etiologies. Intimal calcification is associated with atherosclerosis and occurs in the layer of endothelial cells adjacent to the artery lumen. Medial arterial calcification (MAC) is independent of atherosclerosis and occurs in the middle, muscular layer of the artery. MAC is strongly associated with aging, diabetes mellitus, and chronic kidney disease (CKD). MAC is frequently in patients with peripheral arterial disease (PAD). Most studies to date …

Investigating The Effects Of Calcitonin Gene Related Peptide On Heart Failure And The Gut Microbiome, Talia Charlotte Kepniss

Theses and Dissertations

Heart failure affects millions of people worldwide with current available treatments that are limited in their efficacy. The financial burden for care of those with heart failure is over 20 billion dollars in the US alone. Calcitonin gene related peptide has demonstrated cardioprotective and powerful vasodilator effects. In this study our objective is to prevent the onset of heart failure and treat early stages of heart failure with injections of calcitonin gene related peptide in C57BL/6 mice. In order to model heart failure, experimental mice underwent a transverse aortic constriction surgery. Echocardiograms and fecal collections were completed to observe changes …

Enabling Novel Nanopore Sensing Approaches For Personalized Medicine Through Chemical Modifications To Analytes, Zehui Zhang

Theses and Dissertations

Nanopore sensors have garnered significant attention recently, not only for their groundbreaking advancements in single-molecule DNA sequencing but also for their diverse applications in stochastic sensing, single-molecule chemistry, and protein unfolding. The interaction of single molecules with the nanopore sensing interface leads to characteristic ionic current modulations, reflecting the composition, charge, distribution, structure, and sequence of the translocating molecule. With the electrical resistive pulse nanopore sensing, its single-molecule sensitivity and specificity have opened doors to numerous potential applications in personalized medicine. I will discuss recent advancements in the sensitivity and specificity of personalized medicine using nanopore sensors, focusing on proteomic …

Electrical Conductivity Of Subsurface Ocean Analogue Solutions From Molecular Dynamics Simulations, Catherine A. Psarakis, Timothy Tizhe Fidelis, Keith B. Chin, Baptiste Journaux, Abby Kavner, Pranb Sarker, Marshall J. Stycinski, Steven D. Vance, Tao Wei

Faculty Publications

Investigating the habitability of ocean worlds is a priority of current and future NASA missions. The Europa Clipper mission will conduct approximately 50 flybys of Jupiter’s moon Europa, returning a detailed portrait of its interior from the synthesis of data from its instrument suite. The magnetometer on board has the capability of decoupling Europa’s induced magnetic field to high precision, and when these data are inverted, the electrical conductivity profile from the electrically conducting subsurface salty ocean may be constrained. To optimize the interpretation of magnetic induction data near ocean worlds and constrain salinity from electrical conductivity, accurate laboratory electrical …

Molecular Behavior Of Silicone Adhesive At Buried Polymer Interface Studied By Molecular Dynamics Simulation And Sum Frequency Generation Vibrational Spectroscopy, Yuchen Wu, Ting Lin, Elizabeth Santos, Dongchan Ahn, Ryan Marson, Pranab Sarker, Xiaoyun Chen, Frédéric Gubbels, Nick E. Shephard, Carol Mohler, Tao Wei, Tzu-Chi Kuoc, Zhan Chen

Faculty Publications

Silicones have excellent material properties and are used extensively in many applications, ranging from adhesives and lubricants to electrical insulation. To ensure strong adhesion of silicone adhesives to a wide variety of substrates, silane-based adhesion promotors are typically blended into the silicone adhesive formulation. However, little is known at the molecular level about the true silane adhesion promotion mechanism, which limits the ability to develop even more effective adhesion promoters. To understand the adhesion promotion mechanism of silane molecules at the molecular level, this study has used sum frequency generation vibrational spectroscopy (SFG) to determine the behavior of (3-glycidoxypropyl)trimethoxy silane …

Left Ventricle Function And Post-Transcriptional Events With Exercise Training In Pigs, Stephanie L. Samani, Shayne C. Barlow, Lisa A. Freeburg, Traci L. Jones, Marlee Poole, Mark A. Sarzynski Ph.D., Faha, Facsm, Michael R. Zile, Tarek Shazly, Francis G. Spinale

Faculty Publications

Background

Standardized exercise protocols have been shown to improve overall cardiovascular fitness, but direct effects on left ventricular (LV) function, particularly diastolic function and relation to post-transcriptional molecular pathways (microRNAs (miRs)) are poorly understood. This project tested the central hypothesis that adaptive LV remodeling resulting from a large animal exercise training protocol, would be directly associated with specific miRs responsible for regulating pathways relevant to LV myocardial stiffness and geometry.

Methods and results

Pigs (n = 9; 25 Kg) underwent a 4 week exercise training protocol (10 degrees elevation, 2.5 mph, 10 min, 5 days/week) whereby LV chamber stiffness (KC) …

Left Ventricle Function And Post-Transcriptional Events With Exercise Training In Pigs, Stephanie L. Samani, Shayne C. Barlow, Lisa A. Freeburg, Traci L. Jones, Marlee Poole, Mark A. Sarzynski Facsm, Michael R. Zile, Tarek Shazly, Francis G. Spinale

Faculty Publications

Background

Standardized exercise protocols have been shown to improve overall cardiovascular fitness, but direct effects on left ventricular (LV) function, particularly diastolic function and relation to post-transcriptional molecular pathways (microRNAs (miRs)) are poorly understood. This project tested the central hypothesis that adaptive LV remodeling resulting from a large animal exercise training protocol, would be directly associated with specific miRs responsible for regulating pathways relevant to LV myocardial stiffness and geometry.

Methods and results

Pigs (n = 9; 25 Kg) underwent a 4 week exercise training protocol (10 degrees elevation, 2.5 mph, 10 min, 5 days/week) whereby LV chamber stiffness (KC) …

Eeg Functional Connectivity In Infants At Elevated Familial Likelihood For Autism Spectrum Disorder, Christian O'Reilly, Scott Huberty, Stefon Van Noordt, James Desjardins, Nicky Wright, Julie Scorah, Sara Jane Webb, Mayada Elsabbagh, Basis Team

Publications

Background

Many studies have reported that autism spectrum disorder (ASD) is associated with atypical structural and functional connectivity. However, we know relatively little about the development of these differences in infancy.

Methods

We used a high-density electroencephalogram (EEG) dataset pooled from two independent infant sibling cohorts, to characterize such neurodevelopmental deviations during the first years of life. EEG was recorded at 6 and 12 months of age in infants at typical (N = 92) or elevated likelihood for ASD (N = 90), determined by the presence of an older sibling with ASD. We computed the functional connectivity between …

Leveraging Inflammatory Responses Toward Advancing Alzheimer’S Disease Treatments And Biomaterial Implantation, Mihyun Lim Waugh

Theses and Dissertations

Inflammation is a body’s physiological response to pathogens, foreign materials, or tissue injury. When immune system is triggered, activated leukocytes produce cytokines and chemokines that promote migration of neutrophils and macrophages to the inflammatory regions. At early stages of injury, acute inflammation occurs immediately to fight off the pathogens and restore tissues to homeostasis. However, if the inflammation-inducing stimulus is not removed and thus cells and tissues do not return to its homeostatic state, the prolonged inflammatory responses become a chronic condition. Recent studies have indicated that the receptor for advanced glycation end-products (RAGE), a key receptor of innate immune …

Consolidated Chamber Design And Protocol For Olfactory Conditioning Assay With Drosophila Melanogaster, Sasha Bronovitskiy, Andres Castillo, Michael Yan, Fang Ju Lin

Journal of the South Carolina Academy of Science

The olfactory conditioning assay is widely used in Alzheimer’s disease research to quantify learning and memory in Drosophila melanogaster. The assay tests ability to recall an aversive conditioned stimulus of scent paired with electrical shock when presented a choice between shock-associated and unrelated scents. The T-maze, a commonly used apparatus for olfactory conditioning assays, employs an elevator mechanism to transfer live flies from the shock-delivering training chamber to the scent selection point. This elevator mechanism is known to cause fly casualty. T-mazes are not commercially available and often difficult to reproduce. Other existing variations of olfactory conditioning apparatuses use …

Microcanonical Thermodynamics Of Small Ideal Gas Systems, David S. Corti, Donya Ohadi, Ricardo Fariello, Mark J. Uline

Faculty Publications

We consider the thermal, mechanical, and chemical contact of two subsystems composed of ideal gases, both of which are not in the thermodynamic limit. After contact, the combined system is isolated, and the entropy is determined through the use of its standard connection to the phase space density (PSD), where only those microstates at a given energy value are counted. The various intensive properties of these small systems that follow from a derivative of the PSD, such as the temperature, pressure, and chemical potential (evaluated via a backward difference), while equal when the two subsystems are in equilibrium are nevertheless …

Neurodevelopmental And Transient Impacts Of Brain Kynurenic Acid Elevation And Sleep-Wake Behavior, Katherine Rentschler

Theses and Dissertations

Sleep is vital for healthy cognition and mood. Sleep dysregulation is implicated in psychiatric disorders such as schizophrenia and bipolar disorder. Sex differences in sleep and arousal dysregulation are prominent in patients with psychotic disorders. Elevated levels of the neuroactive tryptophan metabolite, kynurenic acid (KYNA), have been found in cerebrospinal fluid and postmortem brain tissue samples from patients with psychotic disorders. KYNA is an astrocyte derived antagonist at N-methyl-D-aspartate (NMDA) glutamate receptors and α7 nicotinic acetylcholine (α7nACh) receptors. KYNA is synthesized in the brain from its biological precursor, kynurenine, via the enzyme kynurenine aminotransferase II (KAT II), a potential therapeutic …

Gluten Free Diet Ameliorates Si Enteropathy In Iga Deficient Mice, Ryan Albert William Ball

Theses and Dissertations

Secretory IgA is the most abundant antibody in the intestinal mucosal and functions as the first line of defense against pathogens and micro-organisms in the gut. Selective IgA deficiency is the most common form of antibody deficiency. Clinically, IgA deficient patients are largely asymptomatic, they are however at a higher risk of developing certain inflammatory conditions like Celiac disease; an SI-specific enteropathy triggered by exposure to dietary gluten. Interestingly, celiac patients are 10-15 times more likely to have an IgA deficiency. Recent studies have shown that IgA^-/- mice develop enteropathy specifically in the ileum. We confirmed this phenotype in …

Detecting Physiological Concentrations Of Alzheimer’S Associated Amyloid-Β Protein Utilizing A Cell-Based Response, Brittany Elizabeth Watson

Theses and Dissertations

Alzheimer’s disease (AD) is characterized symptoms of cognitive impairment resulting from blood-brain barrier (BBB) breakdown and neuronal cell death. AD is associated with aggregated amyloid-β (Aβ) plaques deposited around brain vasculature and within the brain. Changes in the brain occur up to 20 years before symptoms arise; however, there is currently no pre-symptomatic detection method available for AD. An intact BBB requires tight junction proteins (TJs) that render relatively high transendothelial electrical resistance (TEER). AD-associated breakdown of the BBB correlates with vascular Aβ deposition, suggesting that aggregated, pathological Aβ can modulate TEER. We explore leveraging this cellular response for early …