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Bioactive Self-Forming Hydrogels For Biomedical Applications, Kirstene Arcuino Gultian Giddings

Theses and Dissertations

Hydrogels are soft biomaterials that feature a wide range of physical and biochemical properties. Although highly versatile, hydrogels typically require an exogeneous input (e.g., light, pH, temperature) to form, and this limits their use to conditions where a catalyst is present. The goal of this dissertation is to expand the use of catalyst-based hydrogels by developing hydrogels with independently tunable properties which gel in situ without external stimuli. This new class of hydrogels was developed by first modifying macromers with norbornene (Nor) or tetrazine (Tet) moieties. Macromers containing Nor or Tet remain liquid when dissolved, and upon mixing self-form into …

Transcriptomic Analysis Of A 3d Blood-Brain Barrier Model Exposed To Disturbed Fluid Flow., Nesrine Bouhrira, Brandon J Deore, Kiet A Tran, Peter Galie

Henry M. Rowan College of Engineering Faculty Scholarship

Cerebral aneurysms are more likely to form at bifurcations in the vasculature, where disturbed fluid is prevalent due to flow separation at sufficiently high Reynolds numbers. While previous studies have demonstrated that altered shear stress exerted by disturbed flow disrupts endothelial tight junctions, less is known about how these flow regimes alter gene expression in endothelial cells lining the blood-brain barrier. Specifically, the effect of disturbed flow on expression of genes associated with cell-cell and cell-matrix interaction, which likely mediate aneurysm formation, remains unclear. RNA sequencing of immortalized cerebral endothelial cells isolated from the lumen of a 3D blood-brain barrier …

Recombinant Human Plasma Gelsolin Reverses Increased Permeability Of The Blood-Brain Barrier Induced By The Spike Protein Of The Sars-Cov-2 Virus., Łukasz Suprewicz, Kiet A Tran, Ewelina Piktel, Krzysztof Fiedoruk, Paul A Janmey, Peter Galie, Robert Bucki

Henry M. Rowan College of Engineering Faculty Scholarship

BACKGROUND: Plasma gelsolin (pGSN) is an important part of the blood actin buffer that prevents negative consequences of possible F-actin deposition in the microcirculation and has various functions during host immune response. Recent reports reveal that severe COVID-19 correlates with reduced levels of pGSN. Therefore, using an in vitro system, we investigated whether pGSN could attenuate increased permeability of the blood-brain barrier (BBB) during its exposure to the portion of the SARS-CoV-2 spike protein containing the receptor binding domain (S1 subunit).

MATERIALS AND METHODS: Two- and three-dimensional models of the human BBB were constructed using the human cerebral microvascular endothelial …

Histone Deacetylase 4 And 5 Translocation Elicited By Microsecond Pulsed Electric Field Exposure Is Mediated By Kinase Activity., Zahra Safaei, Gary L. Thompson Iii

Henry M. Rowan College of Engineering Faculty Scholarship

Electroporation-based technologies using microsecond pulsed electric field (µsPEF) exposures are established as laboratory and clinical tools that permeabilize cell membranes. We demonstrate a µsPEF bioeffect on nucleocytoplasmic import and export of enzymes that regulate genetic expression, histone deacetylases (HDAC) -4 and -5. Their μsPEF-induced nucleocytoplasmic transport depends on presence and absence of extracellular calcium ions (Ca

Effects Of Cell-Cell Signaling On Mesenchymal Stem Cell Mechanosensing And Adaptation To Dynamic Material, Matthew E. Lowe

Theses and Dissertations

The goal of this research is to identify the role of engineered cell-cell signals on how cells sense material properties. Mesenchymal stem cells (MSCs) are adult cells whose behavior is regulated by matrix mechanosensing, which is characterized by stiffness-dependent changes in cell shape and the nuclear localization of mechano-transducer proteins including YAP (Yes-associated Protein). MSC area and nuclear YAP translocation increase with increasing stiffness, and although low levels of N-cadherin-based cell-cell signaling reduce this effect, two fundamental questions remain: (1) do engineered cell-cell signals at higher concentrations further reduce matrix mechanosensing, and (2) does N-cadherin signaling affect MSC adaptation to …

The Role Of Small Gtpases In Regulating Blood-Brain Barrier Mechanotransduction, Brandon Jude Deore

Theses and Dissertations

Fluid shear stress is an important mediator of vascular permeability, yet the molecular mechanisms underlying the effect of shear on the blood-brain barrier (BBB) have yet to be clarified in cerebral vasculature despite its importance for brain homeostasis.. Neurological symptoms including the formation of microclots, stroke, and other neurological pathologies associated with changes in cerebral blood flow are hallmarks of BBB dysfunction. The in vitro model used in this dissertation is compatible with real-time measurement of barrier function using a transendothelial electrical resistance as well as immunocytochemistry and dextran permeability assays. These experiments reveal that there is a threshold level …

Bioengineered Scaffolds To Induce Alignment And Promote Axon Regeneration Following Spinal Cord Injury, Kiet Anh Tran

Theses and Dissertations

Scaffolds delivered to injured spinal cords to stimulate axon connectivity often act as a bridge to stimulate regeneration at the injured area, but current approaches lack the permissiveness, topology and mechanics to mimic host tissue properties. This dissertation focuses on bioengineering scaffolds through the means of altering topology in injectables and tuning mechanics in 3D-printed constructs as potential therapies for spinal cord injury repair. A self-assembling peptide scaffold, RADA-16I, is used due to its established permissiveness to axon growth and ability to support vascularization. Immunohistochemistry assays verify that vascularized peptide scaffolds promote axon infiltration, attenuate inflammation and reduce astrogliosis. Furthermore, …

Injectable Hydrogel With Immobilized Bmp-2 Mimetic Peptide For Local Bone Regeneration, Kirstene A. Gultian, Roshni Ghandi, Kayla Decesari, Vineeth Romiyo, Emily P. Kleinbart, Kelsey Martin, Pietro M. Gentile, Tae Won B. Kim, Sebastian Vega

Henry M. Rowan College of Engineering Faculty Scholarship

Osteoporosis is a disease characterized by a decrease in bone mineral density, thereby increasing the risk of sustaining a fragility fracture. Most medical therapies are systemic and do not restore bone in areas of need, leading to undesirable side effects. Injectable hydrogels can locally deliver therapeutics with spatial precision, and this study reports the development of an injectable hydrogel containing a peptide mimic of bone morphogenetic protein-2 (BMP-2). To create injectable hydrogels, hyaluronic acid was modified with norbornene (HANor) or tetrazine (HATet) which upon mixing click into covalently crosslinked Nor-Tet hydrogels. By modifying HANor macromers with methacrylates (Me), thiolated BMP-2 …

Ethanol-Induced Impacts On Nervous System Development And Dopamine Transporter Characterization In Schmidtea Mediterranea Planaria, Brennen Covely

Theses and Dissertations

Fetal alcohol spectrum disorders (FASD) are diagnosed in 2-5% of newborns, but the biology underlying FASD is poorly understood and challenging to study with existing model organisms. A new model for FASD research is Schmidtea mediterranea (Smed) planaria. Smed have a remarkable ability to regenerate their central nervous system (CNS), and possess a well-studied, simple genome. Previous studies have shown that ethanol exposure delays this regeneration, yet this relationship is not fully understood. Here, we show that alcohol exposure affects Smed in a dose-dependent manner, eliciting characteristic withdrawal-like behaviors and impacting cognitive function. Interestingly, prior exposure does not alter subsequent …

Hyaluronic Acid: Its Versatile Use In Ocular Drug Delivery With A Specific Focus On Hyaluronic Acid-Based Polyelectrolyte Complexes., Saoirse Casey-Power, Richie Ryan, Gautam Behl, Peter Mcloughlin, Mark Byrne, Laurence Fitzhenry

Henry M. Rowan College of Engineering Faculty Scholarship

Extensive research is currently being conducted into novel ocular drug delivery systems (ODDS) that are capable of surpassing the limitations associated with conventional intraocular anterior and posterior segment treatments. Nanoformulations, including those synthesised from the natural, hydrophilic glycosaminoglycan, hyaluronic acid (HA), have gained significant traction due to their enhanced intraocular permeation, longer retention times, high physiological stability, inherent biocompatibility, and biodegradability. However, conventional nanoformulation preparation methods often require large volumes of organic solvent, chemical cross-linkers, and surfactants, which can pose significant toxicity risks. We present a comprehensive, critical review of the use of HA in the field of ophthalmology and …

Electro-Mechanical Data Fusion For Heart Health Monitoring, Kemal Yakut

Theses and Dissertations

Heart disease is a major public health problem and one of the leading causes of death worldwide. Therefore, cardiac monitoring is of great importance for the early detection and prevention of adverse conditions. Recently, there has been extensive research interest in long-term, continuous, and non-invasive cardiac monitoring using wearable technology. Here we introduce a wearable device for monitoring heart health. This prototype consists of three sensors to monitor electrocardiogram (ECG), phonocardiogram (PCG), and seismocardiogram (SCG) signals, integrated with a microcontroller module with Bluetooth wireless connectivity. We also created a custom printed circuit board (PCB) to integrate all the sensors into …

Biomimetic Strategies To Control Therapeutic Release From Novel Dna Nanoparticles, Robert J. Mosley

Theses and Dissertations

The inherent chemical, mechanical, and structural properties of nucleic acids make them ideal candidates for the formulation of tunable, personalized drug nanocarriers. However, none so far have exploited these properties for the controlled release of therapeutic drugs. In this dissertation, a biomimetic approach to controlling drug release is exhibited by specifically manipulating the architecture of novel, DNA nanoparticles to take advantage of drug binding mechanisms of action. Rationally designed DNA strands were immobilized on gold surfaces via a terminal thiol modification. Immobilized monomers can be manipulated to form distinct monolayer architectures including flat, folded, coiled, or stretched structures. Increasing the …

Human Induced Mesenchymal Stem Cells Display Increased Sensitivity To Matrix Stiffness., Kirstene A Gultian, Roshni Gandhi, Khushi Sarin, Martina Sladkova-Faure, Matthew Zimmer, Giuseppe Maria De Peppo, Sebastian Vega

Henry M. Rowan College of Engineering Faculty Scholarship

The clinical translation of mesenchymal stem cells (MSCs) is limited by population heterogeneity and inconsistent responses to engineered signals. Specifically, the extent in which MSCs respond to mechanical cues varies significantly across MSC lines. Although induced pluripotent stem cells (iPSCs) have recently emerged as a novel cell source for creating highly homogeneous MSC (iMSC) lines, cellular mechanosensing of iMSCs on engineered materials with defined mechanics is not well understood. Here, we tested the mechanosensing properties of three human iMSC lines derived from iPSCs generated using a fully automated platform. Stiffness-driven changes in morphology were comparable between MSCs and iMSCs cultured …

Porous Scaffold-Hydrogel Composites Spatially Regulate 3d Cellular Mechanosensing., Matthew Dicerbo, Mohammed Mehdi Benmassaoud, Sebastián L Vega

Henry M. Rowan College of Engineering Faculty Scholarship

Cells encapsulated in 3D hydrogels exhibit differences in cellular mechanosensing based on their ability to remodel their surrounding hydrogel environment. Although cells in tissue interfaces feature a range of mechanosensitive states, it is challenging to recreate this in 3D biomaterials. Human mesenchymal stem cells (MSCs) encapsulated in methacrylated gelatin (GelMe) hydrogels remodel their local hydrogel environment in a time-dependent manner, with a significant increase in cell volume and nuclear Yes-associated protein (YAP) localization between 3 and 5 days in culture. A finite element analysis model of compression showed spatial differences in hydrogel stress of compressed GelMe hydrogels, and MSC-laden GelMe …

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 …

Image Processing Algorithms For Detection Of Anomalies In Orthopedic Surgery Implants, Alexander William Wiese

Theses and Dissertations

Orthopedic implant procedures for hip implants are performed on 300,000 patients annually in the United States, with 22.3 million procedures worldwide. While most such operations are successfully performed to relieve pain and restore joint function for the duration of the patient's life, advances in medicine have enabled patients to outlive the life of their implant, increasing the likelihood of implant failure. There is significant advantage to the patient, the surgeon, and the medical community in early detection of implant failures.The research work presented in this thesis demonstrates a non-invasive digital image processing technique for the automated detection of specific arthroplasty …

Annealing Post-Drawn Polycaprolactone (Pcl) Nanofibers Optimizes Crystallinity And Molecular Alignment And Enhances Mechanical Properties And Drug Release Profiles, M. D. Flamini, T. Lima, K. Corkum, N. J. Alvarez, Vincent Beachley

Henry M. Rowan College of Engineering Faculty Scholarship

Post-drawn PCL nanofibers can be molecularly tuned to have a variety of mechanical properties and drug release profiles depending on the temperature and time of annealing, which has implications for regenerative medicine and drug delivery applications. Post-drawing polycaprolactone (PCL) nanofibers has previously been demonstrated to drastically increase their mechanical properties. Here the effects of annealing on post-drawn PCL nanofibers are characterized. It is shown that room temperature storage and in vivo temperatures increase crystallinity significantly on the order of weeks, and that high temperature annealing near melt significantly increases crystallinity and molecular orientation on the order of minutes. The kinetics …

Targeting Hif-2Α In The Tumor Microenvironment: Redefining The Role Of Hif-2Α For Solid Cancer Therapy., Leah Davis, Matthias Recktenwald, Evan Hutt, Schuyler Fuller, Madison Briggs, Arnav Goel, Nichole Daringer

Henry M. Rowan College of Engineering Faculty Scholarship

Inadequate oxygen supply, or hypoxia, is characteristic of the tumor microenvironment and correlates with poor prognosis and therapeutic resistance. Hypoxia leads to the activation of the hypoxia-inducible factor (HIF) signaling pathway and stabilization of the HIF-α subunit, driving tumor progression. The homologous alpha subunits, HIF-1α and HIF-2α, are responsible for mediating the transcription of a multitude of critical proteins that control proliferation, angiogenic signaling, metastasis, and other oncogenic factors, both differentially and sequentially regulating the hypoxic response. Post-translational modifications of HIF play a central role in its behavior as a mediator of transcription, as well as the temporal transition from …

Mechanotransductive Feedback Control Of Endothelial Cell Motility And Vascular Morphogenesis, Devon E. Mason, Megan Goeckel, Sebastian Vega, Pei-Hsun Wu, Dymonn Johnson, Su-Jin Heo, Denis Wirtz, Jason A. Burdick, Levi Wood, Brian Y. Chow, Amber N. Stratman, Joel D. Boerckel

Henry M. Rowan College of Engineering Faculty Scholarship

Vascular morphogenesis requires persistent endothelial cell motility that is responsive to diverse and dynamic mechanical stimuli. Here, we interrogated the mechanotransductive feedback dynamics that govern endothelial cell motility and vascular morphogenesis. We show that the transcriptional regulators, YAP and TAZ, are activated by mechanical cues to transcriptionally limit cytoskeletal and focal adhesion maturation, forming a conserved mechanotransductive feedback loop that mediates human endothelial cell motility in vitro and zebrafish intersegmental vessel (ISV) morphogenesis in vivo. This feedback loop closes in 4 hours, achieving cytoskeletal equilibrium in 8 hours. Feedback loop inhibition arrested endothelial cell migration in vitro and ISV morphogenesis …