Molecular, Cellular, and Tissue Engineering Commons^™

Gold Nanoparticles For Stem Cell Delivery In Myocardial Infarction: Analysis Of Toxicity And Development Of A Cell Culture Platform For Use In An In-Vitro Model Of Mi-Associated Ischemia/Reperfusion, Jeffrey Curran Henson

Graduate Theses and Dissertations

In this work, the potential for PEGylated gold nanoparticles for use as a platform for stem cell delivery in treatment of myocardial infarction (MI) is preliminarily investigated. Cardiovascular disease is currently the leading cause of death worldwide, with majority of mortality resulting from coronary artery disease and associated MI. The ensuing ischemic conditions resulting from MI cause substantial heart muscle tissue loss and scarring in the heart. Adverse tissue remodeling creates a significant loss in heart function that can result in the formation of cardiac hypertrophy, ventricular dilation and arrythmias. The long-term prognosis of patients who have suffered MI is …

Developing Droplet Based 3d Cell Culture Methods To Enable Investigations Of The Chemical Tumor Microenvironment, Jacqueline Alexandria De Lora

Biomedical Sciences ETDs

Adaptation of cancer cells to changes in the biochemical microenvironment in an expanding tumor mass is a crucial aspect of malignant progression, tumor metabolism, and drug efficacy. In vitro, it is challenging to mimic the evolution of biochemical gradients and the cellular heterogeneity that characterizes cancer tissues found in vivo. It is well accepted that more realistic and controllable in vitro 3D model systems are required to improve the overall cancer research paradigm and thus improve on the translation of results, but multidisciplinary approaches are needed for these advances. This work develops such approaches and demonstrates that new droplet-based cell-encapsulation …

Preparation And Characterization Of Functionalized Heparin-Loaded Poly-Ɛ-Caprolactone Fibrous Mats To Prevent Infection With Human Papillomaviruses, Daniela Gonzalez, Jorge Ragusa, Peter C. Angeletti, Gustavo F. Larsen

Department of Chemical and Biomolecular Engineering: Faculty Publications

In this study, heparin-loaded poly-ε-caprolactone (PCL) fibrous mats were prepared and characterized based on their physical, cytotoxic, thermal, and biological properties. The main objective of the work described here was to test the hypothesis that incorporation of heparin into a PCL carrier could serve as bio-compatible material capable of inhibiting Human Papillomavirus (HPV) infection. The idea of firmly anchoring heparin to capture soluble virus, vs. a slow heparin release to inhibit a virus in solution was tested. Thus, one material was produced via conventional heparin matrix encapsulation and electrohydrodynamic fiber processing in one step. A second type of material was …

Developmental Steps For A Functional Three-Dimensional Cell Culture System For The Study Of Asymmetrical Division Of Neural Stem Cells, Martina Zamponi

Biomedical Engineering Theses & Dissertations

Stem cells are a cell type present during and following development, which possess self- renewal properties, as well as the ability to differentiate into specific cells. Asymmetrical division is the cellular process that allows stem cells to produce one differentiated and one un-differentiated daughter cell during the same mitotic event. Insights in the molecular mechanisms of such process are minimal, due to the absence of effective methods for its targeted study. Currently, traditional methods of investigation include monolayer cell culture and animal models. The first poses structural limitations to the accurate representation of human tissue and cell structures, while animal …

Distribution And Localization Of Novel Iodine Nanoparticles In The Human Glioma 1242 Growing In The Brains Of Mice, Benjamin Billings

Honors Scholar Theses

Observing and designing the in vivo distribution and localization of therapeutic nanoparticles is an essential aspect of developing and understanding novel nanoparticle- based medical treatments. This study investigates novel PEGylated Iodine-based nanoparticles (INPs), an alternate composition to the more widely researched gold nanoparticles (AuNPs), which may help avoid adverse effects associated with AuNPs, such as potential toxicity and skin discoloration, when used in similar applications. Determining the localization of the novel INPs within murine brains containing human glioma U-1242MG cells is critical in assisting the development of radiation dose enhancement therapy for this aggressive cancer. Radiation dose enhancement utilizes the …

Modeling Pharmaceutical Inhibition Of Glucose-Stimulated Renin-Angiotensin System In Kidneys, Ashlee N. Ford Versypt, Minu R. Pilvankar, Hui Ling Yong

Biology and Medicine Through Mathematics Conference

No abstract provided.

Soft-Microrobotics: The Manipulation Of Alginate Artificial Cells, Samuel Sheckman

Mechanical Engineering Research Theses and Dissertations

In this work, the approach to the manipulation of alginate artificial cell soft-microrobots, both individually and in swarms is shown. Fabrication of these artificial cells were completed through centrifugation, producing large volumes of artificial cells, encapsulated with superparamagnetic iron oxide nanoparticles; these artificial cells can be then externally stimulated by an applied magnetic field. The construction of a Permeant Magnet Stage (PMS) was produced to manipulate the artificial cells individually and in swarms. The stage functionalizes the permanent magnet in the 2D xy-plane. Once the PMS was completed, Parallel self-assembly (Object Particle Computation) using swarms of artificial cells in complex …

Effects Of Gsk101 Exposure On Astrocyte Mechanical Properties, Collagen Production, And Viability, Ethan Echols

Biomedical Engineering Undergraduate Honors Theses

Transient receptor potential vanilloid 4 (TRPV4) is a cation channel protein which is thought to facilitate extracellular matrix (ECM) modification and glial scar formation following traumatic brain injury (TBI). Activation of TRPV4 has been shown to correlate with an increase in intracellular Ca²⁺ concentration. TRPV4 is subject to both chemical and mechanical activation. This study involved chemical activation of TRPV4 in cultured mouse astrocytes using GSK101, the primary agonist of TRPV4, and subsequent evaluation of mechanical and chemical changes to the ECM. Prior to GSK101 exposure, the cells were seeded into Matrigel Matrix, a gelatinous protein mixture intended to …

Quantification Of Tumor-Associated Macrophages Following Immunomodulation Therapy In A Murine Allograft Model Of Colorectal Carcinoma, Caroline Spainhour

Biomedical Engineering Undergraduate Honors Theses

Colorectal Carcinoma (CRC) is one of the deadliest cancers in the world, with 150,000 new cases annually in the United States. Traditional treatments include chemotherapy and invasive surgery; however, research has shown that only 25% of patients that undergo traditional treatment have a positive result. Immunotherapy is an emerging form of cancer treatment that utilizes the patients’immune system to fight cancer cells by targeting inflammation, which plays a large role in the proliferation and metastasis of cancer cells.

Tumor-associated macrophages (TAMs) are immune cells that affect the inflammatory microenvironment of tumors. TAMs are M1 in the early stages of tumors, …

Structure And Property Of Polymers And Biopolymers From Molecular Dynamic Simulations, Xiaoquan Sun

Graduate Theses and Dissertations

Natural and synthetic polymers and biopolymers have been studied for a variety of applications in food emulsion, biopharmaceutical purification, tissue engineering, and biosensor. The structure and property of polymers and biopolymers are critically important to determine their functions. Molecular dynamics (MD) simulations have a unique advantage to explore the structure and property of polymers and biopolymers from the molecular level. In the dissertation, MD simulations were conducted to study the mechanisms of various biological and chemical processes controlled by polymers and biopolymers based on real-world experimental results.

Seven heptapeptides have been screened from a peptide library in our earlier study …

Novel Methodology For Emboli Analog Production And In-Vitro Simulation Of Acute Ischemic Stroke, Anne Preut

Graduate Theses and Dissertations

Stroke is the leading cause of disability and a primary cause of mortality, resulting in an estimated $33 billion dollars spent on healthcare, rehabilitation and lost productivity in the United States each year. The most prevalent cause of stroke incidents are acute ischemic events, manifested as blood clots in the vasculature supplying the brain. Current gold standard treatments have improved since 2006 with the introduction of mechanical stent retrievers; however, several issues with the current treatments to acute ischemic stroke remain. Thrombolysis of the clot with a tissue plasminogen activator may lead to weakening the vessel wall and consequently, hemorrhaging. …

Analysis Of Biological Response To Ecm Hydrogel Injection, Grady Dunlap

Biomedical Engineering Undergraduate Honors Theses

Abstract

Under normal circumstances, skeletal muscle possesses the capacity to regenerate and heal via inflammatory and myogenic pathways. In cases of severe tissue loss or certain diseases, this capacity is lost, often resulting in loss of tissue function. Extracellular matrix (ECM), the protein scaffold which houses cells in physiological tissue, has been shown to have structural and chemical properties which influence cell migration and phenotype. This results in ECM’s capacity to encourage a regenerative response when implanted into severely damaged skeletal muscle. Additional advantages are apparent when an ECM scaffold is digested into a hydrogel, namely less invasive implantation via …

Designing Synthetic Environments To Control Valvular Interstital Cells In Vitro, Kent E. Coombs

Biomedical Sciences ETDs

Aortic valve disease (AVD) is a large contributor to health costs in the United States affecting 2.8% of the population greater than 75 years old. With a growing elderly population due to medical advances, AVD will continue to rise in prevalence over time. Current treatments for AVD are insufficient due to a lack of preventative therapies and the bioprosthetic valves used for surgical replacement have major limitations. Tissue engineered heart valves (TEHVs) present an ideal solution to current AVD needs because of their biocompatibility, capability to integrate with the host’s tissue, and ability to utilize the natural repair mechanisms of …

Investigation Of Cardiovascular Tissue Following 56fe-Radiation And Potential Countermeasure Effectiveness., Alexandra R Decarlo

Electronic Theses and Dissertations

Exposure to ionizing radiation is an important medical concern because it can lead to health problems including cancer and cardiovascular issues. In space, astronauts are exposed to ionizing radiation that is not experienced by those who remain on Earth. This radiation can cause health problems such as cardiovascular disease. One way this can happen is through the creation of reactive oxygen species, which can activate TGF-β1, contributing to fibrosis or other cardiovascular problems. Antioxidants can be a potential pharmacological mitigator of these excess reactive oxygen species because of their ability to neutralize reactive oxygen species. One such antioxidant with potential …

Plga-Modified Nanoparticles For The Treatment Of Hypo-Vascularized Hpv-Related Cervical Cancers., Lee B. Sims

Electronic Theses and Dissertations

A major challenge associated with delivery of active agents in the female reproductive tract (FRT) is the ability of agents to efficiently diffuse through the cervicovaginal mucosa (CVM) and reach the underlying sub-epithelial immune cell layer and vasculature. A variety of drug delivery vehicles have been employed to improve the delivery of agents across the CVM and offer the capability to increase the longevity and retention of active agents to treat infections of the female reproductive tract. Nanoparticles (NPs) have been shown to improve retention, diffusion, and cell-specific targeting via specific surface modifications, relative to other delivery platforms. In particular, …

Mitochondrial Mrna Translation Is Required For Maintenance Of Oxidative Capacity, David Lee

Graduate Theses and Dissertations

Oxidative metabolism is required to produce adequate energy to sustain human life. A primary example of deteriorating oxidative capacity is seen in the cardiac musculature during chronic heart failure. This suggests that by improving oxidative potential, chronic heart disease could be mitigated and one approach to accomplish this may be through targeting the mt-mRNA translation system. Purpose: This investigation’s purpose was to characterize disruptions in mt-mRNA translation machinery in multiple forms of cardiomyopathy and to determine if mitochondrial mRNA translation initiation factor (mtIF2) is necessary to maintain oxidative capacity in cardiomyocytes. Methods Using a combination of animal and cell culture …

Experimental And Model-Based Terahertz Imaging And Spectroscopy For Mice, Human, And Phantom Breast Cancer Tissues, Tyler Bowman

Graduate Theses and Dissertations

The goal of this work is to investigate terahertz technology for assessing the surgical margins of breast tumors through electromagnetic modeling and terahertz experiments. The measurements were conducted using a pulsed terahertz system that provides time and frequency domain signals. Three types of breast tissues were investigated in this work. The first was formalin-fixed, paraffin-embedded tissues from human infiltrating ductal and lobular carcinomas. The second was human tumors excised within 24-hours of lumpectomy or mastectomy surgeries. The third was xenograft and transgenic mice breast cancer tumors grown in a controlled laboratory environment to achieve more data for statistical analysis.

Experimental …

Eigenstrain As A Mechanical Set-Point Of Cells, Shengmao Lin, Marsha C. Lampi, Cynthia A. Reinhart-King, Gary C.P. Tsui, Jian Wang, Carl A. Nelson, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

Cell contraction regulates how cells sense their mechanical environment. We sought to identify the set-point of cell contraction, also referred to as tensional homeostasis. In this work, bovine aortic endothelial cells (BAECs), cultured on substrates with different stiffness, were characterized using traction force microscopy (TFM). Numerical models were developed to provide insights into the mechanics of cell–substrate interactions. Cell contraction was modeled as eigenstrain which could induce isometric cell contraction without external forces. The predicted traction stresses matched well with TFM measurements. Furthermore, our numerical model provided cell stress and displacement maps for inspecting the fundamental regulating mechanism of cell …

Comparison Of Eosin And Fluorescein Conjugates For The Photoinitiation Of Cell-Compatible Polymer Coatings, Jacob L. Lilly, Anuhya Gottipati, Calvin F. Cahall, Mohamed Agoub, Brad J. Berron

Chemical and Materials Engineering Faculty Publications

Targeted photopolymerization is the basis for multiple diagnostic and cell encapsulation technologies. While eosin is used in conjunction with tertiary amines as a water-soluble photoinitiation system, eosin is not widely sold as a conjugate with antibodies and other targeting biomolecules. Here we evaluate the utility of fluorescein-labeled bioconjugates to photopolymerize targeted coatings on live cells. We show that although fluorescein conjugates absorb approximately 50% less light energy than eosin in matched photopolymerization experiments using a 530 nm LED lamp, appreciable polymer thicknesses can still be formed in cell compatible environments with fluorescein photosensitization. At low photoinitiator density, eosin allows more …

Multiple Factors Drive Variation Of Forest Root Biomass In Southwestern China, Hao Zhang, Kelin Wang, Zhaoxia Zeng, Zhigang Zou, Yanfang Xu, Fuping Zeng

Nebraska Center for Biotechnology: Faculty and Staff Publications

The roots linking the above-ground organs and soil are key components for estimating net primary productivity and carbon sequestration of forests. The patterns and drivers of root biomass in forest have not been examined well at the regional scale, especially for the widely distributed forest ecosystems in southwestern China. We attempted to determine the spatial patterns of root biomass (RB, Mg/ha), annual increment root biomass (AIRB, Mg/ha/year), ratio of root and above-ground (RRA), and the relative contributions of abiotic and biotic factors that drive the variation of root biomass. Forest biomass and multiple factors (climate, soil, forest types, and stand …