Molecular, Cellular, and Tissue Engineering Commons^™

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 …

Diversity And Functional Evolution Of Terpene Synthases In Dictyostelid Social Amoebae, Xinlu Chen, Tobias G. Kollner, Gad Shaulsky, Qidong Jia, Jeroen S. Dickschat, Jonathan Gershenzon, Feng Chen

Nebraska Center for Biotechnology: Faculty and Staff Publications

Dictyostelids, or social amoebae, have a unique life style in forming multicellular fruiting bodies from unicellular amoeboids upon starvation. Recently, dictyostelids were found to contain terpene synthase (TPS) genes, a gene type of secondary metabolism previously known to occur only in plants, fungi and bacteria. Here we report an evolutionary functional study of dictyostelid TPS genes. The number of TPS genes in six species of dictyostelids examined ranges from 1 to 19; and the model species Dictyostelium purpureum contains 12 genes. Using in vitro enzyme assays, the 12 TPS genes from D. purpureum were shown to encode functional enzymes with …

Non-Targeted Colonization By The Endomycorrhizal Fungus, Serendipita Vermifera, In Three Weeds Typically Co-Occurring With Switchgrass, Prasun Ray, Yingqing Guo, Jaydeep Kolape

Nebraska Center for Biotechnology: Faculty and Staff Publications

Serendipita vermifera (=Sebacina vermifera; isolate MAFF305830) is a mycorrhizal fungus originally isolated from the roots of an Australian orchid that we have previously shown to be beneficial in enhancing biomass yield and drought tolerance in switchgrass, an important bioenergy crop for cellulosic ethanol production in the United States. However, almost nothing is known about how this root-associated fungus proliferates and grows through the soil matrix. Such information is critical to evaluate the possibility of non-target effects, such as unintended spread to weedy plants growing near a colonized switchgrass plant in a field environment. A microcosm experiment was conducted …

The Effects Of Emerging Technology On Healthcare And The Difficulties Of Integration, Skyler J. Pavlish-Carpenter

Honors Undergraduate Theses

Background: Disruptive technology describes technology that is significantly more advanced than previous iterations, such as: 3D printing, genetic manipulation, stem cell research, innovative surgical procedures, and computer-based charting software. These technologies often require extensive overhauls to implement into older systems and must overcome many difficult financial and societal complications before they can be widely used. In a field like healthcare that makes frequent advancements, these difficulties can mean that the technology will not be utilized to its full potential or implemented at all.

Objective: To determine the inhibiting factors that prevent disruptive technology from being implemented in conventional healthcare.

Methods: …

Mechanical And Material Characterization Of Advanced Materials For Tissue Regeneration, Bailey Kylara Ricketts Jackson

Theses and Dissertations

In natural disasters and military deployment operations, injury to long bone can cause extensive damage and be difficult to treat and heal quickly. Explosive devices and trauma often produce long-bone (>2-cm length) wounds that are more complicated than common fractures. Due to the size and complexity of these injuries, they can be difficult to treat in a battlefield environment and take a long time to heal completely and properly. Even after the long healing period, these injuries often require rehabilitation to strengthen the muscles that have weakened in the wounded limb. For military applications especially, these effects can put …

Surface Functionalization Via Photoinitiated Radical Polymerization For Rare Cell Isolation And Mechanical Protection, Calvin Frank Cahall

Theses and Dissertations--Chemical and Materials Engineering

Surface functionalization of living cells for cell therapeutics has gained substantial momentum in the last two decades. From encapsulating islets of Langerhans, to cell laden gels for tissue scaffolds, to individual cell encapsulation in thin hydrogels, to surface adhesives and inert surface camouflage, modification of living cell surfaces has a wide array of important applications. Here we use hydrogel encapsulation of individual cells as a mode of protection from mechanical forces for high throughput cell printing, and chemical stimuli for the isolation of rare cells in blood.

In the first study, we review methods of surface functionalization and establish a …

Fibronectin Mechanics And Signaling In Tgf-Β1-Induced Epithelial To Mesenchymal Transition, Lauren Griggs

Theses and Dissertations

Epithelial to Mesenchymal Transition (EMT) is a dynamic process by which a distinct change in the phenotype and function of epithelial cells render them as mesenchymal cells. Characteristics of mesenchymal cells include the ability to invade, increased migratory kinetics and heightened resistance to apoptosis. Therefore, there is a strong need to fully understand the mechanism for the induction of EMT in pathological conditions such as carcinoma progression. Recent advances highlight two pivotal contributors, soluble growth factor (gf) signals, and mechanical signals, in the process. However, to date, no clear mechanism exists linking the two in epithelial transdifferentiation. Transforming Growth Factor-β1 …

Nuclear Rupture In Progeria Expressing Cells, Kranthidhar Bathula

Theses and Dissertations

Cells regularly take on various types of force in the body. They have structures that are able to mediate, transfer and respond to the forces. A mutation in force regulating proteins such as lamin in the nucleus or the KASH domain which connects the nucleus to the cytoskeleton of the cell can cause catastrophic events to occur. The aims of this study were to better understand the response of the nucleus when structural proteins are mutated or are not present while under force. Progeria, a rare disease where an additional farnesyl group is attached to lamin was used in this …

Engineering Surface Properties To Modulate Inflammation And Stem Cell Recruitment Through Macrophage Activation, Kelly M. Hotchkiss

Theses and Dissertations

Biomaterials are becoming the most commonly used therapeutic method for treatment of lost or damaged tissue in the body. Metallic materials are chosen for high strength orthopaedic and dental applications. Titanium (Ti) implants are highly successful in young, healthy patients with the ability to fully integrate to surrounding tissue. However the main population requiring these corrective treatments will not be healthy or young, therefore further research into material modifications have been started to improve outcomes in compromised patients. The body’s immune system will generate a response to any implanted material, and control the final outcome. Among the first and most …

Subject-Independent Emotion Recognition Based On Physiological Signals: A Three-Stage Decision Method, Jing Chen, Bin Hu, Yue Wang, Philip Moore, Yongqiang Dai, Lei Feng, Zhijie Ding

Biomedical Engineering Faculty Publications

Background: Collaboration between humans and computers has become pervasive and ubiquitous, however current computer systems are limited in that they fail to address the emotional component. An accurate understanding of human emotions is necessary for these computers to trigger proper feedback. Among multiple emotional channels, physiological signals are synchronous with emotional responses; therefore, analyzing physiological changes is a recognized way to estimate human emotions. In this paper, a three-stage decision method is proposed to recognize four emotions based on physiological signals in the multi-subject context. Emotion detection is achieved by using a stage-divided strategy in which each stage deals with …

Reducing Biomass Recalcitrance By Heterologous Expression Of A Bacterial Peroxidase In Tobacco (Nicotiana Benthamiana), Ayalew Ligaba-Osena, Bertrand Hankoua, Kay Dimarco, Robert Pace, Mark Crocker, Jesse Mcatee, Nivedita Nagachar, Ming Tien, Tom L. Richard

Center for Applied Energy Research Faculty and Staff Publications

Commercial scale production of biofuels from lignocellulosic feed stocks has been hampered by the resistance of plant cell walls to enzymatic conversion, primarily owing to lignin. This study investigated whether DypB, the lignin-degrading peroxidase from Rodococcus jostii, depolymerizes lignin and reduces recalcitrance in transgenic tobacco (Nicotiana benthamiana). The protein was targeted to the cytosol or the ER using ER-targeting and retention signal peptides. For each construct, five independent transgenic lines were characterized phenotypically and genotypically. Our findings reveal that expression of DypB in the cytosol and ER does not affect plant development. ER-targeting increased protein accumulation, and …

Effects Of Uniaxial Cyclic Strain On Endothelial Progenitor Cells, Maria Alejandra Zeballos Castro

Biomedical Engineering Undergraduate Honors Theses

Despite the high prevalence of calcific aortic valve disease (CAVD), the underlying mechanisms of pathogenesis have not been found yet. Therefore, it is extremely important to study CAVD and understand how it develops. For this matter, we decided to study the potential of endothelial progenitor cells (EPCs) for use in tissue-engineered models of heart valves. EPCs were chosen as the cell source of interest for this study due to their high neovascularization potential and use in regenerative medicine and cardiovascular tissue engineering.

In this project, we aimed to engineer the microenvironment of cells that are involved in the formation of …

Elucidating The Mechanical, Structural, Functional, And Molecular Mechanisms Involved In Irreversible Vascular Changes In Aortic Coarctation, Brandon Wegter

Master's Theses (2009 -)

Coarctation of the aorta (CoA) is a constriction of the thoracic aorta and is one of the most common congenital cardiovascular defects. Treatment by surgical correction has saved the lives of thousands of children, but many still have a reduced lifespan due to hypertension. Previous results using our novel rabbit model showed that the current treatment guideline of a 20 mmHg blood pressure gradient (BPG) induces irreversible vascular changes, which persisted despite correction. Preliminary data of the downregulation of natriuretic peptide receptor C (NPR-C) in proximal aortic tissue of human patients with CoA serves as the possible underlying mechanism for …

Cross-Species Complementation Reveals Conserved Functions For Early Flowering 3 Between Monocots And Dicots, He Huang, Malia A. Gehan, Sarah E. Huss, Sohpie Alvarez, Cesar Lizarraga, Ellen L. Gruebbling, John Gierer, Michael J. Naldrett, Rebacca K. Bindbeutel, Bradley S. Evans, Todd C. Mockler, Dmitri A. Nusinow

Nebraska Center for Biotechnology: Faculty and Staff Publications

Plant responses to the environment are shaped by external stimuli and internal signaling pathways. In both the model plant Arabidopsis thaliana (Arabidopsis) and crop species, circadian clock factors are critical for growth, flowering, and circadian rhythms. Outside of Arabidopsis, however, little is known about the molecular function of clock gene products. Therefore, we sought to compare the function of Brachypodium distachyon (Brachypodium) and Setaria viridis (Setaria) orthologs of EARLY FLOWERING 3, a key clock gene in Arabidopsis. To identify both cycling genes and putative ELF3 functional orthologs in Setaria, a …

Influence Of Fibroblasts On Functional Arteriogenesis In A Murine Chronic Hindlimb Ischemia Model, Ashli A. Santos

Biomedical Engineering

Peripheral arterial occlusive disease (PAOD) occurs when there is a narrowing or blockage – usually a buildup of plaque - within the arteries that reduces blood flow to tissues which can chronic ischemia. As with most diseases, early detection and proactive treatment are important to maximize prognosis. Exercise effectively treats PAOD, but due to ischemic pain in the limbs, or intermittent claudication (IC), exercise can become painful and difficult. Due to the buildup of plaque, occlusions create an ischemic environment that changes the pressure distribution in collateral networks and increases the shear stress in transverse collaterals. Those two responses signal …

Three-Dimensional Microfluidic Tumor Vascular Model For Investigating Breast Cancer Metastasis, Anastasiia Vasiukhina, Brian H. Jun, Luis Solorio, Pavlos P. Vlachos

The Summer Undergraduate Research Fellowship (SURF) Symposium

Metastasis is one of the primary reasons for the high mortality rates in female patients diagnosed with breast cancer. It involves the migration of cancer cells into the circulatory system allowing for the dissemination of cancer cells in distal tissues. Understanding the major processes that occur in cells and tissues during metastasis can help improve currently existing therapeutic methods. In order to understand such mechanisms, developing physiologically relevant tissue models is crucial. Advancements in microfluidics have led to the fabrication of 3D culture models with shear stress gradients and flow control that can recapitulate aspects of the tumor microenvironment in …

Localized Immunosuppression Therapy For Islet Cell Encapsulation, Madeline Mclaughlin, Clarissa Stephens, Sherry Voytik-Harbin

The Summer Undergraduate Research Fellowship (SURF) Symposium

Type 1 diabetes, an autoimmune disease in which the body’s immune system destroys the insulin-producing beta cells necessary for managing a person’s blood glucose levels, affects 1.25 million Americans. A potential treatment for this disease is islet cell transplantation where Islets of Langerhans, containing the beta cells, are transplanted from a normal donor to a diabetic recipient to regulate blood glucose levels and provide insulin independence. Similar to whole organ transplantation, immune modulation through immunosuppression therapy is necessary for successful transplantation of islets without rejection. However, long-term systemic immunosuppression therapy can be toxic to the patient and the islets. Because …

Establishing A Lung Model For Evaluation Of Engineered Lung Microbiome Therapies, Kathryn F. Atherton, Stephen Miloro, Jenna Rickus

The Summer Undergraduate Research Fellowship (SURF) Symposium

Benzene, a toxin and carcinogen found in air polluted by cigarette smoke, car exhaust, and industrial processes, is associated with the development of leukemia and lymphoma. Other than avoiding exposure, there is no current method to deter the effects of benzene. One potential strategy to prevent these effects is to engineer the bacteria of the human lung microbiome to degrade benzene. To evaluate this novel approach, we must verify that the bacteria remain viable within the lung microenvironment. To do so, lungs were harvested from rats and swabbed to determine the contents of the original lung microbiome. Then green fluorescent …

A Novel High-Throughput, High-Content Three-Dimensional Assay For Determination Of Tumor Invasion And Dormancy, Mahera M. Husain, Theodore J. Puls, Sherry Voytik-Harbin

The Summer Undergraduate Research Fellowship (SURF) Symposium

Metastasis accounts for most cancer deaths, while dormancy of tumor cells leads to unexpected cancer recurrence. These two aspects of cancer remain relatively untreatable in part because current two-dimensional (2D) methods of high-throughput drug screening cannot quantify outcomes related to these phenotypes. Three-dimensional (3D) in-vitro tumor models are a promising alternative because they better recreate the tumor microenvironment and relevant phenotypes. However, outcome measures for high-throughput screening of these systems are often limited to single measures such as metabolic activity using assays that are not standardized or optimized for 3D models. To address this gap, the objective of this work …

Fret Biosensors: Engineering Fluorescent Proteins As Biological Tools For Studying Parkinson’S Disease, Nathan J. Leroy, Jacob R. Norley, Saranya Radhakrishnan, Mathew Tantama

The Summer Undergraduate Research Fellowship (SURF) Symposium

Parkinson’s Disease (PD) is a common neurodegenerative disease with over 200,000 new cases each year. In general, the cause of the disease is unknown, but oxidative stress inside of neurons has been associated with the disease’s pathology for some time. Currently, techniques to study the onset of PD inside of neurons are limited. This makes treatments and causes difficult to discover. One solution to this has been fluorescent protein biosensors. In short, these proteins can be engineered to glow when a certain state is achieved inside a cell. The present research discusses the engineering of a genetically-encoded fluorescent protein (FP) …