Molecular, Cellular, and Tissue Engineering Commons^™

Incorporation Of Egfr And Ron Receptors Into Nanodiscs, Cristina Flores-Cadengo

Biomedical Engineering ETDs

Understanding the structure-function relationship of membrane receptors is essential to comprehend the crosstalk between key signaling pathways. Aberrant trans-activation between receptors can lead to tumorigenesis. Two of these receptors known to be involved in cancer development are receptor tyrosine kinases (RTKs), RON (Recepteur d'Origine Nantais) and EGFR (Epidermal Growth Factor Receptor). There has been evidence of heterodimerization and crosstalk between these two receptors based on co-immunoprecipitation, however the structural requirements behind these interactions remain unknown. Structural studies could provide insights into these RTKs’ modes of dimerization and structure-function relationship. However, structural studies of full-length membrane proteins are often difficult due …

Plga Scaffold Device, Tyler D. Tackabery, Bryce Powada, Tate Morell

Biomedical Engineering

No abstract provided.

Fluid Delivery System For A Cell Culture On A Microfluidic Chip, Austin J. Roeder, Colleen A. Richards, Emily A. Matteson

Biomedical Engineering

This project report provides a description of the progress made in the development of a fluid delivery system for a microfluidic cell culture on a chip. The system is intended to be used in a humidified incubator in a university laboratory and the fluid delivery system is required to exist and operate within that incubator for extended periods of time. Therefore, the system will be gravity-driven and contain no electronic components. The key specification of the system is to provide fluid flow at a constant velocity.

After manufacturing and testing the device, all specifications were met except for the fluid …

Pressure Cylinder Controlled Release Valve, Alexa Dominique Balbuena

Biomedical Engineering

This project aims to integrate an automatic gas release system in a pre-existing scaffold fabrication process for tissue engineering applications.

To form the proper scaffold structure, the fabrication process is heavily influenced by the change in its surrounding pressure. The current production involves a pressure transducer and electric valve that is managed manually to create a suitable pressure environment for the scaffold. This method, although functional, proves to be ineffective when creating several batches; the user needs to constantly monitor the developing pressure profile and alter voltage parameters accordingly to create a linear gas release under a predetermined slope.

To …

Advanced Selection Methodologies For Dnazymes In Sensing And Healthcare Applications, Sandeep Kumar, Shikha Jain, Neeraj Dilbaghi, Amrik Singh Ahluwalia, Ashraf Aly Hassan, Ki-Hyun Kim

Department of Civil and Environmental Engineering: Faculty Publications

DNAzymes have been widely explored owing to their excellent catalytic activity in a broad range of applications, notably in sensing and biomedical devices. These newly discovered applications have built high hopes for designing novel catalytic DNAzymes. However, the selection of efficient DNAzymes is a challenging process but one that is of crucial importance. Initially, systemic evolution of ligands by exponential enrichment (SELEX) was a labor-intensive and time-consuming process, but recent advances have accelerated the automated generation of DNAzyme molecules. This review summarizes recent advances in SELEX that improve the affinity and specificity of DNAzymes. The thriving generation of new DNAzymes …

Metabolomics Of Sorghum Roots During Nitrogen Stress Reveals Compromised Metabolic Capacity For Salicylic Acid Biosynthesis, Amy M. Sheflin, Dawn Chiniquy, Chaohui Yuan, Emily Goren, Indrajit Kumar, Max Braud, Thomas Brutnell, Andrea L. Eveland, Susannah Tringe, Peng Liu, Stephen Kresovich, Ellen Marsh, Daniel P. Schachtman, Jessica E. Prenni

Nebraska Center for Biotechnology: Faculty and Staff Publications

Sorghum (Sorghum bicolor [L.] Moench) is the fifth most productive cereal crop worldwide with some hybrids having high biomass yield traits making it promising for sustainable, economical biofuel production. To maximize biofuel feedstock yields, a more complete understanding of metabolic responses to low nitrogen (N) will be useful for incorporation in crop improvement efforts. In this study, 10 diverse sorghum entries (including inbreds and hybrids) were field-grown under low and full N conditions and roots were sampled at two time points for metabolomics and 16S amplicon sequencing. Roots of plants grown under low N showed altered metabolic profiles at …

Disciplinary Learning From An Authentic Engineering Context, Catherine Langman, Judith Zawojewski, Patricia Mcnicholas, Ali Cinar, Eric Brey, Mustafa Bilgic, Hamidreza Mehdizadeh

Journal of Pre-College Engineering Education Research (J-PEER)

This small-scale design study describes disciplinary learning in mathematical modeling and science from an authentic engineeringthemed module. Current research in tissue engineering served as source material for the module, including science content for readings and a mathematical modeling activity in which students work in small teams to design a model in response to a problem from a client. The design of the module was guided by well-established principles of model-eliciting activities (a special class of problem-solving activities deeply studied in mathematics education) and recently published implementation design principles, which emphasize the portability of model-eliciting activities to many classroom settings.

Two …

Terpene Synthase Genes Originated From Bacteria Through Horizontal Gene Transfer Contribute To Terpenoid Diversity In Fungi, Qidong Jia, Xinlu Chen, Tobias G. Kollner, Jan Rinkel, Jianyu Fu, Jessy Labbe, Wangdan Xiong, Jeroen S. Dickschat, Jonathan Gershenzon, Feng Chen

Nebraska Center for Biotechnology: Faculty and Staff Publications

Fungi are successful eukaryotes of wide distribution. They are known as rich producers of secondary metabolites, especially terpenoids, which are important for fungi-environment interactions. Horizontal gene transfer (HGT) is an important mechanism contributing to genetic innovation of fungi. However, it remains unclear whether HGT has played a role in creating the enormous chemical diversity of fungal terpenoids. Here we report that fungi have acquired terpene synthase genes (TPSs), which encode pivotal enzymes for terpenoid biosynthesis, from bacteria through HGT. Phylogenetic analysis placed the majority of fungal and bacterial TPS genes from diverse taxa into two clades, indicating ancient …

Human Islet Response To Selected Type 1 Diabetes-Associated Bacteria: A Transcriptome-Based Study, Ahmed M. Abdellatif, Heather Jensen Smith, Robert Z. Harms, Nora Sarvetnick

Journal Articles: Regenerative Medicine

Type 1 diabetes (T1D) is a chronic autoimmune disease that results from destruction of pancreatic β-cells. T1D subjects were recently shown to harbor distinct intestinal microbiome profiles. Based on these findings, the role of gut bacteria in T1D is being intensively investigated. The mechanism connecting intestinal microbial homeostasis with the development of T1D is unknown. Specific gut bacteria such as Bacteroides dorei (BD) and Ruminococcus gnavus (RG) show markedly increased abundance prior to the development of autoimmunity. One hypothesis is that these bacteria might traverse the damaged gut barrier, and their constituents elicit a response from human islets that causes …

Designing Biomimetic Implant Surfaces To Promote Osseointegration Under Osteoporotic Conditions By Revitalizing Mechanisms Coupling Bone Resorption To Formation, Ethan M. Lotz

Theses and Dissertations

In cases of compromised bone remodeling like osteoporosis, insufficient osseointegration occurs and results in implant failure. Implant retention relies on proper secondary fixation, which is developed during bone remodeling. This process is disrupted in metastatic bone diseases like osteoporosis. Osteoporosis is characterized low bone mass and bone strength resulting from either accelerated osteoclast-mediated bone resorption or impaired osteoblast-mediated bone formation. These two processes are not independent phenomena. In fact, osteoporosis can be viewed as a breakdown of the cellular communication connecting bone resorption to bone formation. Because bone remodeling occurs at temporally generated specific anatomical sites and at different times, …

A Microfluidic Tissue Array (Μfta) For Personalized Medicine Using Tumor Biopsies, A.H. R. Ahmed

Dissertations and Theses

Cancer is recognized as a complex disease with both genetic and epigenetic drivers that can vary from one individual to another. While very early research into cancer treated it as a clonal malfunction that could originate from as small as a single deregulated cell, the disease itself manifests itself with several more complexities beyond tumorigenic cells only. The tumor microenvironment itself – from the extracellular matrix to stromal cells - cooperate with tumor cells in a symbiotic manner towards metastatic progression. Clinical studies have provided more information regarding the degree of individualization possible, such that patients with similar genetic makeup …

Modification Of Lipid Microenvironments On Solid Support Structures For Use In Transmembrane Protein Assays, William J. Houlihan

Dissertations and Theses

Gamma-Secretase (γ-secretase) is a transmembrane protease of increasing interest, which has been shown to have significant connections to both cancer and Alzheimer’s disease. γ-secretase cleaves both Notch-1, a transmembrane signaling protein, and Amyloid precursor protein (APP), a transmembrane protein whose cleavage may result in the formation of β-amyloid plaques in the brain. Notch-1 and APP are widely studied proteins that have substantial impacts on the development and proliferation of cancer and Alzheimer’s disease, respectively. Notch-1 partakes in the signaling of apoptosis in damaged and mutated cells, thus its cleavage by γ-secretase within the plasma membrane has ramifications on cell growth …

Controlled Migration Of Retinal Progenitor Cells Within Electro-Chemotactic Fields, Shawn Mishra

Dissertations and Theses

Vision loss in retinal degenerative diseases is overwhelmingly attributed to damage and death of retinal photoreceptor cells. Studies in mouse retina have suggested that transplantation of isolated post-natal or stem cell-derived retinal progenitor cells (RPCs) to replace apoptotic or damaged photoreceptors may be a novel approach to restore vision. Thus far, outcomes project that the amount of restored visual response depends upon the migration of transplanted cells from insertion in the sub-retinal space to the outer nuclear layer (ONL). However, transplantation efficiency is exceedingly low – ~5% cells transplanted enter the retina – directly limiting the efficacy of the treatments. …

Glioma Grading Using Structural Magnetic Resonance Imaging And Molecular Data, Syed M.S. Reza, Manar D. Samad, Zeina A. Shboul, Karra A. Jones, Khan M. Iftekharuddin

Electrical & Computer Engineering Faculty Publications

A glioma grading method using conventional structural magnetic resonance image (MRI) and molecular data from patients is proposed. The noninvasive grading of glioma tumors is obtained using multiple radiomic texture features including dynamic texture analysis, multifractal detrended fluctuation analysis, and multiresolution fractal Brownian motion in structural MRI. The proposed method is evaluated using two multicenter MRI datasets: (1) the brain tumor segmentation (BRATS-2017) challenge for high-grade versus low-grade (LG) and (2) the cancer imaging archive (TCIA) repository for glioblastoma (GBM) versus LG glioma grading. The grading performance using MRI is compared with that of digital pathology (DP) images in the …

Design And Mechanical Characterization Of 3d Printed Gradient Porosity Poly(Propylene Fumarate) Scaffolds, Andrea Felicelli

Williams Honors College, Honors Research Projects

Worldwide incidence of bone disorders and conditions, an already prevalent problem, is expected to double by 2020 from the rate in 2013 due to factors such as higher life expectancies and lower levels of physical activity. Every year in the United States, over half a million patients receive bone defect repairs, with costs greater than $2.5 billion. Current repairs are typically done with bone grafts, which are often costly and can result in added complications in the donor surgical site. Tissue engineering, a growing field that seeks to assist and enhance tissue defect repairs through the use of synthetic materials, …

The Production And Characterization Of Chitosan Based Microgels Using A Novel Microfluidic Device To Promote Cell Survival, Kaileen Shevchuk

Williams Honors College, Honors Research Projects

The purpose of this project is to synthesize and characterize perfluorocarbon modified methacrylamide chitosan (MACF) microgels produced with the use of a capillary-based microfluidic device. Since cell survival and development is highly related to particles physical properties, analysis of microgels set out to determine the particle’s physical properties. I hypothesize that the viscosity of the MACF polymer as well as the amount of photo initiator influence the physical properties of synthesized particles and as a result can generate particles with various features for cell culture in terms of shape, size, charge and swelling abilities. This hypothesis was validated through the …

Cell Type And Substrate Dependence Of Fibronectin Properties And Mechanotransduction, Navpreet S. Saini

Theses and Dissertations

Fibronectin is an important protein that is able to bind to other fibronectin molecules and to cell surface receptors. In doing so, the interactions fibronectin can perform is important for the processes of cell migration and tissue formation. Understanding the properties of fibronectin and fibril assembly is useful for areas such as wound healing, where fibronectin molecules are assembled to protect the tissue and to perform other tasks. Because of these reasons, it is important to understand how fibronectin is assembled and how its properties affect the fibril assembly, which in return affects the way the cell matrix operates. Previously …

The Small Rna Teg41 Regulates Expression Of The Alpha Phenol-Soluble Modulins And Is Required For Virulence In Staphylococcus Aureus, Rachel L. Zapf, Richard E. Wiemels, Rebecca A. Keogh, Donald L. Holzschu, Kayla M. Howell, Emily Trzeciak, Andrew R. Caillet, Kellie A. King, Samantha A. Selhorst, Michael J. Naldrett, Jeffrey L. Bose, Ronan K. Carroll

Nebraska Center for Biotechnology: Faculty and Staff Publications

Small RNAs (sRNAs) remain an understudied class of regulatory molecules in bacteria in general and in Gram-positive bacteria in particular. In the major human pathogen Staphylococcus aureus, hundreds of sRNAs have been identified; however, only a few have been characterized in detail. In this study, we investigate the role of the sRNA Teg41 in S. aureus virulence. We demonstrate that Teg41, an sRNA divergently transcribed from the locus that encodes the cytolytic alpha phenolsoluble modulin (αPSM) peptides, plays a critical role in αPSM production. Overproduction of Teg41 leads to an increase in αPSM levels and a corresponding increase in …

Delineating The Role Of Fanca In Glucose-Stimulated Insulin Secretion In Β Cells Through Its Protein Interactome, Dragana Lagundzin, Wen-Feng Hu, Henry C. H. Law, Kimiko L. Krieger, Fangfang Qiao, Emalie J. Clement, Andjela T. Drincic, Olgica Nedic, Michael J. Naldrett, Sophie Alvarez, Nicholas T. Woods

Nebraska Center for Biotechnology: Faculty and Staff Publications

Hyperinsulinemia affects 72% of Fanconi anemia (FA) patients and an additional 25% experience lowered glucose tolerance or frank diabetes. The underlying molecular mechanisms contributing to the dysfunction of FA pancreas β cells is unknown. Therefore, we sought to evaluate the functional role of FANCA, the most commonly mutated gene in FA, in glucosestimulated insulin secretion (GSIS). This study reveals that FANCA or FANCB knockdown impairs GSIS in human pancreas β cell line EndoC-βH3. To identify potential pathways by which FANCA might regulate GSIS, we employed a proteomics approach to identify FANCA protein interactions in EndoC-βH3 differentially regulated in response to …

Cell Surface Coatings For Mammalian Cell-Based Therapeutic Delivery, Pei-Jung Wu

Theses and Dissertations--Chemical and Materials Engineering

The cell plasma membrane is an interactive interface playing an important role in regulating cell-to-cell, cell-to-tissue contact, and cell-to-environment responses. This environment-responsive phospholipid layer consisting of multiple dynamically balanced macromolecules, such as membrane proteins, carbohydrate and lipids, is regarded as a promising platform for various surface engineering strategies. Through different chemical modification routes, we are able to incorporate various artificial materials into the cell surface for biomedical applications in small molecule and cellular therapeutics.

In this dissertation, we establish two different cell coating techniques for applications of cell-mediated drug delivery and the localization of cell-based therapies to specific tissues. The …

The Role Of The Mechanical Environment On Cd117+ Endothelial Cell Angiogenesis, Patrick Link

Theses and Dissertations

Angiogenesis is a complex process coordinating cell migration, proliferation, and lumen formation. Changes to the microenvironment regulate angiogenesis through mechanotransduction and cytokine signals. In pulmonary hypertension, something in the process becomes abnormal, resulting in changes to the microenvironment and the formation of a glomerulus of dysfunctional capillaries, called a plexiform lesion. Endothelial cells, expressing CD117 (CD117+ EC clones) increase in the plexiform lesions of pulmonary hypertension, independent of pro-angiogenic VEGF signaling. We hypothesize that the mechanical environment and the macromolecular composition of the extracellular matrix, both, contribute to the aberrant angiogenesis. When we changed the mechanical environment, we changed the …

Engineering The Alveolar Gas Exchange Barrier With Extracellular Matrix Coatings For Bioengineered Lungs, Bethany M. Young

Theses and Dissertations

Lower respiratory diseases are currently the third leading cause of death worldwide. For many end-stage patients with these diseases, there is no cure and a shortage of donor organs available for transplant. A promising solution is to design regenerative scaffolds or complete bioengineered lungs, using decellularized lung tissues as a template for regeneration. Recent advances in the field have made significant strides towards developing a transplantable lung. However, the current technology has not produced a functional lung for in vivo transplant due to immature gas exchange barriers. The mechanisms driving alveolar barrier maturation and role that extracellular matrix (ECM) plays …

Eralpha Isoforms Modulate The Tumorigenicity Of 24r,25(Oh)2d3 In Estrogen-Responsive Cancer, Anjali Verma

Theses and Dissertations

Over 200,000 cases of breast cancer are diagnosed every year. Nearly 20% of these patients supplement their diets with some form of vitamin D. This high frequency of vitamin D supplement use may be due in part to research suggesting that cancer patients with higher serum vitamin D₃ levels have better prognoses than patients with low serum vitamin D_3. However, double-blind clinical trials on the efficacy of vitamin D₃ supplementation in breast cancer have been inconclusive. A recent meta-analysis showed evidence of reduced cancer recurrence in patients taking vitamin D₃ supplements who had ‘estrogen receptor positive’ …

Mechanochemical Regulation Of Epithelial Tissue Remodeling: A Multiscale Computational Model Of The Epithelial-Mesenchymal Transition Program, Lewis Scott

Theses and Dissertations

Epithelial-mesenchymal transition (EMT) regulates the cellular processes of migration, growth, and proliferation - as well as the collective cellular process of tissue remodeling - in response to mechanical and chemical stimuli in the cellular microenvironment. Cells of the epithelium form cell-cell junctions with adjacent cells to function as a barrier between the body and its environment. By distributing localized stress throughout the tissue, this mechanical coupling between cells maintains tensional homeostasis in epithelial tissue structures and provides positional information for regulating cellular processes. Whereas in vitro and in vivo models fail to capture the complex interconnectedness of EMT-associated signaling networks, …