Molecular, Cellular, and Tissue Engineering Commons^™

Characterization Of Phase Behavior In Idp Solutions By Uv-Vis Spectrophotometry And Phase Volume Fraction Measurements In Capillaries, Qing Sun

Biomedical Engineering ETDs

Intrinsically disordered proteins (IDPs) play vital roles in cell signaling and regulation by changing conformation dynamically under various stimulus. Thus, it is crucial to understand their physical properties in vitro especially liquid-liquid phase separation (LLPS). Here, we first used UV-vis spectrophotometry to investigate two of IDPs' physical properties – transition temperature (Tt) and coacervate size. This deeper insight allows us to further understand the dynamics of phase growth. We then constructed a binodal curve in the phase diagram by measurement of volume ratios in phase separated IDP solution in glass capillaries.

The Rotator Cuff Tendon-To-Bone Interface: Maturation, Aging, And 3d Bioprinting For Regeneration, Xiping Jiang

Theses & Dissertations

Rotator cuff tendon injuries often occur at the tendon-to-bone interface (i.e., enthesis) area with a high prevalence for the elderly population. In addition, regeneration of the gradient structure of the enthesis is still a significant clinical challenge. Our studies aim to identify the histological, molecular, and biomechanical alterations of the rotator cuff enthesis with maturation and aging, and develop a novel therapeutic method using three-dimensional (3D) bioprinting technique to regenerate a functional enthesis. Striking variations of the entheses were observed both histologically and biomechanically during the maturation process. The histological features did not show many differences at the insertion site …

Novel Approaches For Enhancing Cell Survival And Function In Vivo, Ou Wang

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

FDA has approved several cell-based therapeutics and hundreds of cell therapy clinical trials are ongoing. Cells will be a significant type of medicine after small molecule and protein drugs. However, several obstacles need to be addressed to achieve the widespread use of cellular therapeutics. The first challenge is the low efficacy of cell transplantation due to low retention, survival, integration, and function of cells in vivo. The second challenge is producing a massive number of cells for clinical treatment with cost-effectively and reproducibly technologies.

In this thesis, we proposed and investigated two approaches to address these challenges. To begin …

Tissue Engineering And The Effect Of Volumetric Muscle Loss On Muscle Performance, Alex Pemberton

Biomedical Engineering Undergraduate Honors Theses

Trauma, for so many people, creates life altering injuries. One of the major injuries that results from trauma is volumetric muscle loss (VML), which is the loss of muscle tissue that cannot be naturally regenerated and results in chronic loss of function. When a small amount of damage is done to a muscle, but the underlying extracellular matrix of the cell is still intact, the muscle can regenerate much of its volume and function. If the injury damages the extracellular matrix, the injury site is instead filled with scar tissue, which cannot regenerate muscle mass or function. Seen widely in …

Assessing The Effects Of Oxaliplatin On An In Vitro Three-Dimensional Human Colorectal Cancer Model, Sabrina Nelson

Master's Theses

Colorectal cancer is the third most common cancer in the United States with a 5-year late-stage survival rate of only 14%. Due to the lack of translation between animal models and clinical trials as well as the inefficacy of many chemotherapeutics in initial clinical trials, researchers are turning to in vitro drug screening models in an effort to mimic the conditions in vivo. This research project aimed to validate an in vitro tumor culture model within a microfluidic device using a clinically relevant chemotherapy drug. The first experiment consisted of a cell density and drug concentration study to determine …

Longitudinal Monitoring Of Tumor Response To Immune Checkpoint Inhibitors Using Diffuse Optical Spectroscopy, Joel Isaac Rodriguez Troncoso

Graduate Theses and Dissertations

Immune checkpoint drugs have completely changed the way people treat metastatic melanoma and non-small-cell lung cancer. While the impacts of these immunological checkpoints and their suppression on T cell function are well characterized, their consequences on the tumor microenvironment are not. In a CT26 mouse colorectal cancer model, we employed diffuse reflectance spectroscopy to track in vivo tumor microenvironmental alterations in response to immune checkpoint inhibitors. On three separate days, animals bearing CT26 tumor xenografts were given anti-PD-L1, anti-CTLA-4, a combination of both inhibitors, and isotype control. Within the first 6 days, monotherapy with either anti-PD-L1 or anti-CTLA-4 resulted in …

Investigation On Effects Of Lactate Adaptation Using Metabolic Indicators And Amino Acids To Explore Cell Metabolism, Lisa Uy

All Theses

Biopharmaceutical products are drugs that are made from living cells. One protein type of high importance to biopharmaceuticals is monoclonal antibodies. Monoclonal antibodies allow for highly specific, targeted treatment of diseases and detection of molecules related to diseases. With major roles in detecting and/or treating diseases like human immunodeficiency virus (HIV), coronavirus disease 2019 (COVID-19), and some cancers, monoclonal antibodies are in demand. This demand has led to a need for efficient cell culture systems to produce high yields of protein with minimal waste. The most commonly used cell culture system for these high-value proteins is Chinese hamster ovary (CHO) …

Investigating Effects Of Microenvironmental Stress On Cell Metabolism Using Multiphoton Imaging, Lisa Rebello

Graduate Theses and Dissertations

Resistance to therapy in cancer is a major cause of poor prognosis in patients. Tumor hypoxia plays an active role in mediating treatment resistance and has been linked to metastases and metastatic potential in cancer. Our research focused on three objectives: i) To understand metabolic effects of chronic and intermittent hypoxia in murine breast cancer cells and its affiliation with metastatic potential ii) To identify the metabolic changes associated with radiation therapy in a panel of radiosensitive and radioresistant human head and neck cancer cells and iii) to monitor the changes in cell metabolism associated with gain of treatment resistance. …

Phenolic, Carotenoid And Saccharide Compositions Of Vietnamese Camellia Sinensis Teas And Herbal Teas, Danh C. Vu, Sophie Alvarez

Nebraska Center for Biotechnology: Faculty and Staff Publications

Tea (Camellia sinensis) and herbal tea have been recognized as rich sources of bioactive constituents with the ability to exert antioxidant actions. The aims of this study were to analyze phenolic, carotenoid and saccharide contents in a set of Vietnamese tea and herbal tea and compare the results with those of green and black teas marketed in the U.S. In total, 27 phenolics, six carotenoids and chlorophylls, and three saccharides were quantitatively identified. Catechins, quercetin glycosides and chlorogenic acid were the predominating phenolics in the teas, with the concentrations following the order: jasmine/green teas > oolong tea > black tea. …

Defining The Innate Immune Responses For Sars-Cov-2-Human Macrophage Interactions, Mai M. Abdelmoaty, Pravin Yeapuri, Jatin Machhi, Katherine E. Olson, Farah Shahjin, Vikas Kumar, You Zhou, Jingjing Liang, Kabita Pandey, Arpan Acharya, Siddappa N. Byrareddy, R. Lee Mosley, Howard E. Gendelman

Nebraska Center for Biotechnology: Faculty and Staff Publications

Host innate immune response follows severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, and it is the driver of the acute respiratory distress syndrome (ARDS) amongst other inflammatory end-organ morbidities. Such life-threatening coronavirus disease 2019 (COVID-19) is heralded by virus-induced activation of mononuclear phagocytes (MPs; monocytes, macrophages, and dendritic cells). MPs play substantial roles in aberrant immune secretory activities affecting profound systemic inflammation and end-organ malfunctions. All follow the presence of persistent viral components and virions without evidence of viral replication. To elucidate SARS-CoV- 2-MP interactions we investigated transcriptomic and proteomic profiles of human monocyte-derived macrophages. While expression of the …

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 …

A Single Cell Pair Mechanical Interrogation Platform To Study Cell–Cell Adhesion Mechanics, Amir Monemianesfahani

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Cell-cell adhesion complexes are macromolecular adhesive organelles that integrate cells into tissues. Perturbations of the cell-cell adhesion structure or relatedmechanotransduction pathways lead to pathological conditions such as skin and heart diseases, arthritis, and cancer. Mechanical stretching has been used to stimulate the mechanotransduction process originating from the cell-cell adhesion and cell-extracellular matrix (ECM) complexes. The current techniques, however, have limitations on their ability to measure the cell-cell adhesion force directly and quantitatively. These methods use a monolayer of cells, which makes it impossible to quantify the forces within a single cell-cell adhesion complex. Other methods using single cells or cell …

A Systematic Review And Meta-Analysis On The Efficacy Of Stem Cell Therapy On Bone Brittleness In Mouse Models Of Osteogenesis Imperfecta, Lauren Battle, Shoshana Yakar, Alessandra Carriero

Publications and Research

There is no cure for osteogenesis imperfecta (OI), and current treatments can only partially correct the bone phenotype. Stem cell therapy holds potential to improve bone quality and quantity in OI. Here, we conduct a systematic review and meta-analysis of published studies to investigate the efficacy of stem cell therapy to rescue bone brittleness in mouse models of OI. Identified studies included bone marrow, mesenchymal stem cells, and human fetal stem cells. Effect size of fracture incidence, maximum load, stiffness, cortical thickness, bone volume fraction, and raw engraftment rates were pooled in a random-effects meta-analysis. Cell type, cell number, injection …

Correlating Diffusional Dynamics And Receptor Tyrosine Kinase Function Using Single Quantum Dot Tracking, Irais Ortiz Caraveo

Biomedical Engineering ETDs

Epidermal growth factor receptor (EGFR) signal transduction is initiated via ligand (EGF) binding, followed by dimerization, autophosphorylation of the C-terminal tails, and recruitment of proteins that form a larger signaling complex to propagate the signal. We explored the relationship between receptor mobility and signaling using single-particle tracking (SPT) by examining the diffusional dynamics of EGFR and two truncation mutants to understand whether mobility changes are correlated with signaling. Results revealed that phosphorylation of the C-terminal tail of EGFR is required for maximal reduction in mobility that occurs with EGF stimulation, indicating that receptor mobility is a read-out for receptor signaling. …

Arhgdia Confers Selective Advantage To Dissociated Human Pluripotent Stem Cells, Marion J. Riggs, Steven D. Sheridan, Raj R. Rao

Biomedical Engineering Faculty Publications and Presentations

Human pluripotent stem cells (hPSCs) have generated significant interest in the scientific community based on their potential applications in regenerative medicine. However, numerous research groups have reported a propensity for genomic alterations during hPSC culture that poses concerns for basic research and clinical applications. Work from our laboratory and others has demonstrated that amplification of chromosomal regions is correlated with increased gene expression. To date, the phenotypic association of common genomic alterations remains unclear and is a cause for concern during clinical use. In this study, we focus on trisomy 17 and a list of candidate genes with increased gene …

Synthesis And Performance Testing Of Ecm Fiber Scaffolds, Cassandra Reed

Graduate Theses and Dissertations

The progression of regenerative medicine has advanced the treatment of multiple illnesses and injuries throughout the years. A good example of the benefits of this research is the work that has gone into volumetric muscle loss (VML), where more than 20% of the muscle is loss. Skeletal muscle makes up 40% of the human body so a loss of that size greatly diminishes the strength, the flexibility, physiology, and quality of life of the injured individual. For that reason, various techniques are used to counteract the loss of structure and innate cellular signaling in order to circumvent that from happening. …

Review And Analysis Of Methods For Measuring Concentration Of Suspended Substances And Active Sludge During Biological Treatment Of Waste Water, Maxsud Maxmudov, Siroj Nurov, Zafar Qo'ziev, Sanjar Sidiqov

Scientific-technical journal

This work analyzes and compares the measuring and technical characteristics of methods for measuring and controlling the parameters of activated sludge in the processes of biological wastewater treatment. As methods for measuring the concentration of activated sludge, methods such as the optical method, the ultrasonic method and the method for measuring the nuclear density of a liquid are considered. The principles of operation of each of these methods are illustrated with graphic drawings for more clarity of the interaction of the measuring signal with the particles of the measured medium. At the end of the work, conclusions on the characteristics …

The Impact Of Myoblast Transplantation On Collateral Capillary Arteriogenesis And Macrophage Phenotype, Christine Hue Do

Biomedical Engineering

Gangrene, pain, loss of limb function, amputation, and death are only few of the grievous consequences associated with peripheral arterial disease (PAD), a vascular disease caused by an obstruction that narrows the blood vessels. Since some patients have collateral vessels that can re-route blood to its downstream destination, much focus has been spotlighted upon discovering the mechanism of this process, termed arteriogenesis, as well as cell therapies to increase arterial diameter of collateral vessels. Since some patients do not have native pre-existing collateral vessels, another method to re-route blood is through arterialized collateral capillaries (ACC), which is the conversion of …

Heparan Sulfate Proteoglycan Glypican‑1 And Pecam‑1 Cooperate In Shear‑Induced Endothelial Nitric Oxide Production, Anne Marie W. Bartosch, Rick Mathews, Marwa M. Mahmoud, Limary M. Cancel, Zahin S. Haq, John M. Tarbell

Publications and Research

This study aimed to clarify the role of glypican-1 and PECAM-1 in shear-induced nitric oxide production in endothelial cells. Atomic force microscopy pulling was used to apply force to glypican-1 and PECAM-1 on the surface of human umbilical vein endothelial cells and nitric oxide was measured using a fluorescent reporter dye. Glypican-1 pulling for 30 min stimulated nitric oxide production while PECAM-1 pulling did not. However, PECAM-1 downstream activation was necessary for the glypican-1 force-induced response. Glypican-1 knockout mice exhibited impaired flow-induced phosphorylation of eNOS without changes to PECAM-1 expression. A cooperation mechanism for the mechanotransduction of fluid shear stress …

Impact Of Angiogenic And Osteogenic Factors In The Presence Of Biodegradable Piezoelectric Films, Jayla Millender

University Scholar Projects

One of the most common causes of bone graft rejection is lack of a vascular network connecting the graft to the existing native tissue – allowing for nutrient flow. Under current grafting techniques, the existing blood vessel network in the patient slowly invades the implant in order to supply the injured site with its necessary nutrients. The purpose of this research is to determine if a synthetic bone graft with a stable microvascular network can be developed in vitro. I hypothesize that the use of indirect angiogenic factors such as sonic hedgehog homolog and hypoxia-inducible factor-1 in combination with the …

Impact Of Angiogenic And Osteogenic Factors In The Presence Of Biodegradable Piezoelectric Films, Jayla Millender

Honors Scholar Theses

One of the most common causes of bone graft rejection is lack of a vascular network connecting the graft to the existing native tissue – allowing for nutrient flow. Under current grafting techniques, the existing blood vessel network in the patient slowly invades the implant in order to supply the injured site with its necessary nutrients. The purpose of this research is to determine if a synthetic bone graft with a stable microvascular network can be developed in vitro. I hypothesize that the use of indirect angiogenic factors such as sonic hedgehog homolog and hypoxia-inducible factor-1 in combination with the …

Diagnosis Of Melanoma Disease State From Patient Blood Samples Using Photoacoustic Flow Cytometry, Jacob Salvatore

Electronic Theses and Dissertations

Approximately 1 in 50 Americans develop melanoma in their lifetime. Early detection of melanoma is pivotal to the survival of the patient, with a 99% survival rate for 5 or more years after an early diagnosis. Metastasis, or the spread of cancer, increases the chances of cancerous growth in other parts of the body. In this study, we propose the use of photoacoustic flow cytometry as a diagnostic of patient disease state, by closely monitoring the amount of circulating melanoma cells (CMCs) in a patient’s blood before and after chemotherapy treatments. Using this patient data, we were able to make …

Guide Rnas Preparation For In-Vitro Crispr-Cas9 Complex Delivery Targeting Genes That Affect Wound Healing., Prashant Khatiwada

Biomedical Engineering Undergraduate Honors Theses

CRISPR-Cas9 technology has widely been used as a viable genome engineering platform to make site-specific insertion, deletion, and breaks. The nuclease dead version of Cas9 or dCas9 can be used for the activation and repression of target gene sites using specific activation or repression domains. In this study, CRISPR guide RNAs were designed for a CRISPR inhibition approach to repress the transcriptional activity of the target genes. An expression plasmid vector composed of a U6 promoter sequence, BbsI restriction sites, and a chimeric gRNA sequence was digested, and the phosphorylated forward and reverse gRNAs were ligated with the plasmid vector. …

Evaluating Cellular Response Of Different Valve Interstitial Cell (Vic) Phenotypes To Angiotensin I, Smit Patel

Biomedical Engineering Undergraduate Honors Theses

Calcific Aortic Valve Disease (CAVD), one of the leading causes of death in the United States, is characterized by diminished functioning and limited movement of the aortic valve (AV) due to increased thickening, disorganized extracellular matrix elastin fibers, increased collagen content, and abnormal deposition and formation of calcium nodules on the AV [1, 2]. There are two types of CAVD: i) Aortic valve sclerosis (AVS), in which patients suffer from tissue hardening, fibrosis, and early calcification, and ii) calcific aortic stenosis (CAS), representative by excessive calcification on the AV and reduced AV opening, are the two main forms of CAVD …

Involvement Of The Ino80 Chromatin Remodeling Complex In Cell Division And Genomic Stability, Ethan Chen

Biomedical Engineering Undergraduate Honors Theses

Cell division is a vital biological process for growth and development in both single and multi-cellular organisms—whereby the cell must duplicate its organelles and genome in entirety and appropriately distribute the copied contents to the daughter cells. Cells undergo a cycle of two distinct phases: interphase and mitosis. During interphase, the cell replicates its genomic DNA (in the form of chromosomes) located within the nucleus. DNA replication is carried out in a euchromatin state, where the chromosome structure is loose and easily accessible by DNA polymerase and other replication enzymes. Upon the completion of replication, chromatin is condensed into highly …

Mapping The Domain Of Rna Helicase Ddx1 That Interacts With The Ns1 Of Influenza A Viruses, Elise Wyatt

Biomedical Engineering Undergraduate Honors Theses

Of the known influenza virus strains, influenza A viruses (IAVs) are the most catastrophic due to their highly contagious nature and possibly life-threatening symptoms. IAVs invade a host cell and enter the nucleus where they use the cell’s nuclear machinery for replication of their viral RNA genome which is then exported to neighboring cells to establish a productive infection. Host pathogen recognition receptors (PRRs) respond to viral infection by signaling the cell to produce type I interferons (IFNs) to fight the foreign invader. Non-structural protein 1 (NS1) of IAVs, a major component in the regulation of viral replication, opposes host …

Developing Aligned Nerve Scaffolds In A 3d Type-I Collagen Gel, Gabriel David

Biomedical Engineering Undergraduate Honors Theses

Despite significant progress in the field of peripheral nerve repair, clinical success is still limited, leaving millions to suffer from peripheral neuropathy with billions spent every year for treatment. Nerve repair methods that are capable of maximizing the regenerative properties of peripheral nerves are greatly desired in the field of medical science. This research aims to fill the gap between modern methods and the future of nerve repair by creating type-I collagen scaffolds with aligned degradation pores that will assist and nurture nerves growing through them. This is achieved by incorporating adipose stem cells into type-I collagen hydrogels and aligning …

Development Of An Integrated Salt Cartridge-Reverse Electrodialysis (Red) Device To Increase Electrolyte Concentrations Of Human Blood Flow To Power Biomedical Devices, Caroline Campbell

Chemical Engineering Undergraduate Honors Theses

Emerging technologies in nanotechnology and biomedical sciences have led to an increase in biomedical implantable devices including cardiac pacemakers, artificial organs, drug pumps, and sensors. These devices require continuous stable and reliable power to operate, which creates the demand for the need to find a safe, reliable, and stable power source. A promising avenue for a power source for these devices is a miniaturized reverse electrodialysis (RED) biopower cell design that utilizes the salinity differences between bloodstreams that flow inside the human body. Initial results of the RED system demonstrate that higher gradient salinity differences between streams lead to a …

Evaluating The Effects Of Wood Source On The Physicochemical Properties Of Crosslinked Cellulose Nanocrystals, Helena Tchoungang Nkeumen

Graduate Theses and Dissertations

Cellulose is an abundant and naturally occurring biopolymer that has been used by humans for food, shelter, and clothing for about two centuries now. Highly crystalline nanoparticles derived from cellulose, called cellulose nanocrystals (CNCs), show great potential to meet the rising need for sustainable and nontoxic materials for biomedical applications. However, multiple biomedical applications of CNCs, such as those involving their use in tissue engineering scaffolds, require CNC-based structures to be stable in aqueous environments, a property that native CNCs do not possess due to their inherent hydrophilicity. Chemical crosslinking of CNCs addresses this issue by providing aqueous stability to …

Development And Applications Of In-Vitro And In-Silico Models Of The Cardiovascular System To Study The Effects Of Mechanical Circulatory Support., Moustafa Meki

Electronic Theses and Dissertations

Cardiovascular diseases (CVDs) are the leading cause of mortality globally. With ongoing interest in CVDs treatment, preclinical models for drug/therapeutic development that allow for fast iterative research are needed. Owing to the inherent complexity of the cardiovascular system, current in-vitro models of the cardiovascular system fail to replicate many of the physiological aspects of the cardiovascular system. In this dissertation, the main concern is with heart failure (HF). In advanced HF, patients may receive Left Ventricular Assist Devices (LVADs) as a bridge to transplant or destination therapy. However, LVADs have many limitations, including inability to adapt to varying tissue demand …