Biomedical Engineering and Bioengineering Commons^™

Next-Generation Mrna Sequencing Reveals Pyroptosis-Induced Cd4+ T Cell Death In Early Simian Immunodeficiency Virus-Infected Lymphoid Tissues, Wuxun Lu, Andrew J. Demers, Fangrui Ma, Guobin Kang, Zhe Yuan, Yanmin Wan, Yue Li, Jiangqing Xu, Mark Lewis, Qingsheng Li

Nebraska Center for Biotechnology: Faculty and Staff Publications

Lymphoid tissues (LTs) are the principal sites where human immunodeficiency virus type 1 (HIV-1) replicates and virus-host interactions take place, resulting in immunopathology in the form of inflammation, immune activation, and CD4+ T cell death. The HIV-1 pathogenesis in LTs has been extensively studied; however, our understanding of the virus-host interactions in the very early stages of infection remains incomplete. We investigated virus-host interactions in the rectal draining lymph nodes (dLNs) of rhesus macaques at different times after intrarectal inoculation (days postinoculation [dpi]) with simian immunodeficiency virus (SIV). At 3 dpi, 103 differentially expressed genes (DEGs) were detected using next-generation …

Incorporation Of Fibrin Into A Collagen–Glycosaminoglycan Matrix Results In A Scaffold With Improved Mechanical Properties And Enhanced Capacity To Resist Cell-Mediated Contraction, Claire Brougham, Tanya J. Levingstone, Stefan Jockenhoevel, Thomas C. Flanagan, Fergal J. O'Brien

Articles

Fibrin has many uses as a tissue engineering scaffold, however many in vivo studies have shown a reduction in function resulting from the susceptibility of fibrin to cell-mediated contraction. The overall aim of the present study was to develop and characterise a reinforced natural scaffold using fibrin, collagen and glycosaminoglycan (FCG), and to examine the cell-mediated contraction of this scaffold in comparison to fibrin gels. Through the use of an injection loading technique, a homogenous FCG scaffold was developed. Mechanical testing showed a sixfold increase in compressive modulus and a thirtyfold increase in tensile modulus of fibrin when reinforced with …

Investigation Of Bovine Serum Albumin (Bsa) Attachment Onto Self-Assembled Monolayers (Sams) Using Combinatorial Quartz Crystal Microbalance With Dissipation (Qcm-D) And Spectroscopic Ellipsometry (Se), Hanh T.M. Phan, Shannon L. Bartelt-Hunt, Keith B. Rodenhausen, Mathias Schubert, Jason C. Bartz

Department of Civil and Environmental Engineering: Faculty Publications

Understanding protein adsorption kinetics to surfaces is of importance for various environmental and biomedical applications. Adsorption of bovine serum albumin to various selfassembled monolayer surfaces including neutral and charged hydrophilic and hydrophobic surfaces was investigated using in-situ combinatorial quartz crystal microbalance with dissipation and spectroscopic ellipsometry. Adsorption of bovine serum albumin varied as a function of surface properties, bovine serum albumin concentration and pH value. Charged surfaces exhibited a greater quantity of bovine serum albumin adsorption, a larger bovine serum albumin layer thickness, and increased density of bovine serum albumin protein compared to neutral surfaces at neutral pH value. The …

Mimicking The Arterial Microenvironment With Peg-Pc To Investigate The Roles Of Physicochemical Stimuli In Smc Phenotype And Behavior, William G. Herrick

Doctoral Dissertations

The goal of this dissertation was to parse the roles of physical, mechanical and chemical cues in the phenotype plasticity of smooth muscle cells (SMCs) in atherosclerosis. We first developed and characterized a novel synthetic hydrogel with desirable traits for studying mechanotransduction in vitro. This hydrogel, PEG-PC, is a co-polymer of poly(ethylene glycol) and phosphorylcholine with an incredible range of Young’s moduli (~1 kPa - 9 MPa) that enables reproduction of nearly any tissue stiffness, exceptional optical and anti-fouling properties, and support for covalent attachment of extracellular matrix (ECM) proteins. To our knowledge, this combination of mechanical range, low …

Three-Dimensional Confocal Microscopy Indentation Method For Hydrogel Elasticity Measurement, Donghee Lee, Md Mahmudur Rahman, You Zhou, Sangjin Ryu

Md Mahmudur Rahman

No abstract provided.

Buckling-Driven Force Generation Of Cell Cortex, Pranith Lomada, Wonyeong Jung, Taeyoon Kim

The Summer Undergraduate Research Fellowship (SURF) Symposium

Actomyosin cortex, a thin network underlying cell membrane, is known to generate a large portion of tensile forces required for various cellular processes. Recently, theoretical studies predicted that buckling of actin filaments breaks symmetry between tensile and compressive forces developed by myosin motors, resulting in tensile stress at a network level. However, the significance of the filament buckling of the cortex has yet to be demonstrated either computationally or experimentally. Here, buckling-dependent stress generation of the cortex-like actomyosin network was investigated using an agent-based computational model consisting of actin filaments, actin cross-linking proteins (ACPs), and molecular motors. First, a wide …

Selective Protein Labelling To Visualize Cellular Differentiation, Andrew J. Witten, Tamara L. Kinzer-Ursem

The Summer Undergraduate Research Fellowship (SURF) Symposium

Protein post-translational modifications serve to give proteins new cellular function, spatial localization, or enzymatic activity. Myristoylation is a common post-translational modification where the enzyme N-myristoyltransferase adds myristic acid onto the N-terminus of a variety of proteins. In this work we use a myristic acid analog, 12-azidododecanoic acid (12ADA) to facilitate the implementation of azide-alkyne cycloaddition reactions on myristoylated proteins. Selective protein labeling methods such as these are useful in research because they can be used to help determine the biological function of this protein lipid modification and can be extended to study disregulated protein myristoylation in disease states. To validate …

Harnessing Notch Signaling For Biomaterial Scaffold-Based Bone Regeneration, Helena P. Lysandrou, Chunhui Jiang, Naagarajan Narayanan, Shihuan Kuang, Meng Deng

The Summer Undergraduate Research Fellowship (SURF) Symposium

Bone fracture has recently become prevalent, especially with an increasingly aging population. Current bone grafts procedures, including autografts and allografts, are hindered by multiple factors, such as limited supplies and inconsistent bone healing. Scaffold-based bone tissue engineering emerges as a prospective strategy to aid in bone regeneration through delivery of growth factors such as bone morphogenic proteins (BMPs). However, the use of BMPs suffers from several drawbacks such as protein instability and immunogenicity. Therefore, there exists a great need for the development of novel therapies to promote bone healing. Notch signaling, a pathway critical for cell-fate determination has been shown …

Viewing The Extracellular Matrix: An Imaging Method For Tissue Engineering, Michael Drakopoulos, Sarah Calve

The Summer Undergraduate Research Fellowship (SURF) Symposium

The field of regenerative medicine seeks to create replacement tissues and organs, both to repair deficiencies in biological function and to treat structural damage caused by injury. Scaffoldings mimicking extracellular matrix (ECM), the structure to which cells attach to form tissues, have been developed from synthetic polymers and also been prepared by decellularizing adult tissue. However, the structure of ECM undergoes significant remodeling during natural tissue repair, suggesting that ECM-replacement constructs that mirror developing tissues may promote better regeneration than those modeled on adult tissues. This work investigated the effectiveness of a method of viewing the extracellular matrix of developing …

Bioengineered Cell Niche For Skeletal Muscle Regeneration, Nicole M. Whittern, Naagarajan Narayanan, Chunhui Jiang, Owen Jones, Jay Gilbert, Michael Whittern, Shihuan Kuang, Meng Deng

The Summer Undergraduate Research Fellowship (SURF) Symposium

Skeletal muscles can self-repair minor strains, lacerations, and contusions; however, in cases of volumetric muscle lossand muscle degenerative diseases, tissue fails to regenerate. Current cell-based therapies, such as myoblast transplantation, have significant drawbacks of low survival rates and engraftment efficacy, mainly due to the absence of supportive cell microenvironment. Scaffolds that mimic the natural cell microenvironment provide a robust platform to support cell adhesion, migration, proliferation, and differentiation. Electrospinning is a versatile technology platform used for fabricating the fiber scaffold that mimics the extracellular matrix. Thus, we aim to reconstitute the cell microenvironment through development of aligned fiber scaffolds by …

Proteoglycan Mimic Of The Glycocalyx To Treat Endothelial Dysfunction, Victoria Messerschmidt, Alyssa Panitch, James R. Wodicka

The Summer Undergraduate Research Fellowship (SURF) Symposium

Patients with kidney failure usually undergo hemodialysis, a process by which toxins produced by the body are filtered from the blood, in order to survive. The preferred form for vascular access is called an arteriovenousfistula (AVF), a surgically created connection between an artery and vein that is utilized to undergo dialysis. However, AVFs have a failure rate of 50-60%. One of the contributions to AVF failure is endothelial cell dysfunction and loss of glycocalyx, which allows neutrophils and other native cells into the media of the vessel, which causes an inflammatory response. Our lab addresses endothelial dysfunction by mimicking the …

Microengineering The Neural Tube, Christopher Demers

Electronic Theses and Dissertations

Early embryonic development is a complex and highly regulated orchestra of instructive cues that collectively guide naïve stem cells towards progressively more specialized fates. In the neural tube, the precursor structure to the brain and spinal cord, these signals emanate from ‘organizing centers’ surrounding the neural tube. These organizing centers send out soluble cues or morphogens that diffuse tens to hundreds of microns to recipient cells residing in the neural tube. Re-creating this dynamic landscape of cues in vitro is impossible using standard cell culture tools and techniques. However, microfluidics is perfectly suited to fill this gap, allowing precise control …

Breast Cancer/Stromal Cells Coculture On Polyelectrolyte Films Emulates Tumor Stages And Mirna Profiles Of Clinical Samples, Amita Daverey, Karleen M. Brown, Srivatsan Kidambi

Department of Chemical and Biomolecular Engineering: Faculty Publications

In this study, we demonstrate a method for controlling breast cancer cells adhesion on polyelectrolyte multilayer (PEM) films without the aid of adhesive proteins/ ligands to study the role of tumor and stromal cell interaction on cancer biology. Numerous studies have explored engineering coculture of tumor and stromal cells predominantly using transwell coculture of stromal cells cultured onto coverslips that were subsequently added to tumor cell cultures. However, these systems imposed an artificial boundary that precluded cell−cell interactions. To our knowledge, this is the first demonstration of patterned coculture of tumor cells and stromal cells that captures the temporal changes …

Biodegradable Nano-Hybrid Polymer Composite Networks For Regulating Cellular Behavior, Charles Henley Sprague

Masters Theses

Photo-crosslinkable polymeric biomaterials have emerged in the field of biomedical research to promote tissue regeneration. For example, scaffolds that can be crosslinked and hardened in situ have been known to make suitable implant alternatives. Since injectable and photo-crosslinkable biomaterials offer the advantage of being minimally invasive, they have emerged to compete with autografts, a current highly invasive method to repair diseased tissue. A series of novel photo-crosslinkable, injectable, and biodegradable nano-hybrid polymers consisting of poly(ε-caprolactone fumarate) (PCLF) and polyhedral oligomeric silsesquioxane (POSS) has been synthesized in our laboratory via polycondensation. To engineer the material properties of the nano-hybrid networks, varied …

Monitoring The Progression Of Spontaneous Articular Cartilage Healing With Infrared Spectroscopy, Megan P. O'Brien, Madhuri Penmatsa, Uday Palukuru, Paul West, Xu Yang, Mathias P. G. Bostrom, Theresa Freeman, Nancy Pleshko

Publications and Research

Objective. Evaluation of early compositional changes in healing articular cartilage is critical for understanding tissue repair and for therapeutic decision-making. Fourier transform infrared imaging spectroscopy (FT-IRIS) can be used to assess the molecular composition of harvested repair tissue. Furthermore, use of an infrared fiber-optic probe (IFOP) has the potential for translation to a clinical setting to provide molecular information in situ. In the current study, we determined the feasibility of IFOP assessment of cartilage repair tissue in a rabbit model, and assessed correlations with gold-standard histology.

Design. Bilateral osteochondral defects were generated in mature white New Zealand rabbits, and …

Capillary Electrophoresis For Analysis Of Aβ1-42 Adsorption And Photo-Crosslinking, Jennifer Lynn Kurtz

Graduate Theses and Dissertations

The accumulation of amyloid-beta (Aβ) oligomers is believed to be the driving force behind Alzheimer’s disease (AD) pathogenesis. Due to the metastable nature of Aβ oligomers, the knowledge of Aβ aggregation and accumulation is not well understood. Here, we use capillary electrophoresis (CE) and photo-induced crosslinking of unmodified proteins (PICUP) to learn about the aggregation of Aβ.

First, we explore the effect of capillary coating on Aβ1-42 protein loss using CE. The dynamic coatings tested were PHEA and 50 kDa, 2000 kDa, 5000 kDa, and 8000 kDa PEO. The covalent coating tested was PVA. The results indicated that 2000 kDa …

Characterization Of Human Muscle Extracellular Matrix, Lauren Klaire Wilson

Graduate Theses and Dissertations

The performance of extracellular matrix (ECM) biological scaffolds for the treatment of volumetric muscle loss (VML) has shown promising results with regenerating native muscle in animal models and human patients. However, the limitations of these scaffolds include non-specific characteristics based on the original parameters of the muscle that is lost and this is why our group chose to characterize human skeletal ECM. By understanding the characteristics of the native human skeletal ECM, more desired queues for the biological scaffolds being used to treat VML can be provided. Upper limb and lower limb skeletal muscles were commercially obtained, decellularized using common …

Selection Methods For Genetically-Modified T Cells: In Support Of Translational Therapy, David Rushworth

Dissertations & Theses (Open Access)

T cells are blood cells which organize the immune system of the host. These cells are necessary for the host to respond appropriately to threats from foreign organisms and cancerous growth. However, in the case of certain infections and cancer, T cells are unable to respond appropriately to a threat and establish immunity. This leads to disease when the infection or cancer is not sufficiently eliminated. On the other hand, T cells can lack tolerance for healthy tissue and perceive healthy tissue as infected. The ensuing over-reactive immune response also leads to disease. A delicate balance must exist between immunity …

Design And Development Of Two Component Hydrogel Ejector For Three-Dimensional Cell Growth, Thomas Dunkle, Jessica Deschamps, Connie Dam

Honors Scholar Theses

Hydrogels are useful in wound healing, drug delivery, and tissue engineering applications, but the available methods of injecting them quickly and noninvasively are limited. The medical industry does not yet have access to an all-purpose device that can quickly synthesize hydrogels of different shapes and sizes. Many synthesis procedures that have been developed result in the formation of amorphous hydrogels. While generally useful, amorphous hydrogels exhibit limited capability in tissue engineering applications, especially due to their viscous properties. This endeavor aims to modulate the appropriate gelation parameters, optimize the injection process, and create a prototype that allows for the extrusion …

Finite Element Analysis Of The Application Of Ultrasound-Generated Acoustic Radiation Force To Biomaterials, Nicole J. Piscopo

Honors Scholar Theses

While most bone fractures can heal simply by being stabilized, others can take a longer time to rejoin or they could fail to merge back together completely. Numerous studies have shown the positive effects that ultrasonic therapy have had on delayed-union and non-union bone fracture repair but little is known as to what specific biological mechanisms are at play. Ultrasound may be a valuable tool for bone tissue regeneration at these fracture sites using a tissue engineering approach, however, more must be understood about its impact on stimulating tissues to heal before this can be a reality. For that reason, …

Mitochondrial Dysfunction And Loss Of Glutamate Uptake In Primary Astrocytes Exposed To Titanium Dioxide Nanoparticles, Christina L. Wilson

Department of Chemical and Biomolecular Engineering: Theses and Student Research

The proper function of astrocytes is critical for brain health as they are the most abundant cells in the brain which monitor ion homeostasis, recycle neurotransmitters and respond to tissue damage therefore disruption in astrocyte function can result in overall detrimental effects and has been linked with neurodegenerative diseases. Titanium Dioxide (TiO₂) nanoparticles are currently the second most produced engineered nanomaterial in the world with vast usage in consumer products leading to recurrent human exposure. Animal studies indicate significant nanoparticle accumulation in the brain while cellular toxicity studies demonstrate negative effects on neuronal cell viability and function. However, …

Man Made Organs: Technology Made It Possible But Can The Fda Keep Up?, Amanda Chatman

North Carolina Central University Science & Intellectual Property Law Review

No abstract provided.

Fiber Scaffolds Of Poly (Glycerol-Dodecanedioate) And Its Derivative Via Electrospinning For Neural Tissue Engineering, Xizi Dai

FIU Electronic Theses and Dissertations

Peripheral nerves have demonstrated the ability to bridge gaps of up to 6 mm. Peripheral Nerve System injury sites beyond this range need autograft or allograft surgery. Central Nerve System cells do not allow spontaneous regeneration due to the intrinsic environmental inhibition. Although stem cell therapy seems to be a promising approach towards nerve repair, it is essential to use the distinct three-dimensional architecture of a cell scaffold with proper biomolecule embedding in order to ensure that the local environment can be controlled well enough for growth and survival. Many approaches have been developed for the fabrication of 3D scaffolds, …

Engineering Periodontal Tissue Regeneration With The Use Of A Novel Periostin Electrospun Scaffold, Kendal I. Creber

Electronic Thesis and Dissertation Repository

Clinical therapies for the treatment of periodontitis are unable to reproducibly stimulate regeneration of the periodontium. We assessed the use of a novel electrospun type I collagen scaffold containing recombinant periostin to stimulate regeneration of the periodontal ligament (PDL) and bone. Human PDL cells demonstrated the ability to form a mineralized matrix in vitro and reduced osteogenic potential with increased donor age. In vitro analysis indicated scaffolds were biocompatible, however, periostin did not significantly influence adhesion or growth. In the healing of fenestration defects in rats, type I collagen scaffolds (with and without periostin) initially delayed cell infiltration and increased …

Integrating Top-Down And Bottom-Up Scaffolding Tissue Engineering Approach For Bone Regeneration, M. Ramalingam, Esmaiel Jabbari, S. Ramakrishna, A. Khademhosseini

Esmaiel Jabbari

No abstract provided.

Bioinspired Nanomaterials For Bone Regeneration, Esmaiel Jabbari

Esmaiel Jabbari

No abstract provided.

Nanoparticles For Stem-Cell Engineering, Esmaiel Jabbari

Esmaiel Jabbari

No abstract provided.

Altered Cd161bright Cd8+ Mucosal Associated Invariant T (Mait)-Like Cell Dynamics And Increased Differentiation States Among Juvenile Type 1 Diabetics., Robert Z. Harms, Kristina M. Lorenzo, Kevin P. Corley, Monina S. Cabrera, Nora Sarvetnick

Journal Articles: Regenerative Medicine

Type 1A diabetes (T1D) is believed to be caused by immune-mediated destruction of β-cells, but the immunological basis for T1D remains controversial. Microbial diversity promotes the maturation and activation of certain immune subsets, including CD161bright CD8+ mucosal associated invariant T (MAIT) cells, and alterations in gut mucosal responses have been reported in type 1 diabetics (T1Ds). We analyzed T cell populations in peripheral blood leukocytes from juvenile T1Ds and healthy controls. We found that proportion and absolute number of MAIT cells were similar between T1Ds and controls. Furthermore, while MAIT cell proportions increased with age among healthy controls, this trend …

Theoretical Investigation Of Intra- And Inter-Cellular Spatiotemporal Calcium Patterns In Microcirculation, Jaimit B. Parikh

FIU Electronic Theses and Dissertations

Microcirculatory vessels are lined by endothelial cells (ECs) which are surrounded by a single or multiple layer of smooth muscle cells (SMCs). Spontaneous and agonist induced spatiotemporal calcium (Ca²⁺) events are generated in ECs and SMCs, and regulated by complex bi-directional signaling between the two layers which ultimately determines the vessel tone. The contractile state of microcirculatory vessels is an important factor in the determination of vascular resistance, blood flow and blood pressure. This dissertation presents theoretical insights into some of the important and currently unresolved phenomena in microvascular tone regulation. Compartmental and continuum models of isolated EC …

Thermosensitive Gel Containing Cellulose Acetate Phthalate-Efavirenz Combination Nanoparticles For Prevention Of Hiv-1 Infection, Abhijit A. Date, Annemarie Shibata, Emily Mcmullen, Krista La Bruzzo, Patrick Bruck, Michael Belshan, You Zhou, Christopher J. Destache

Nebraska Center for Biotechnology: Faculty and Staff Publications

The objective of this investigation was to develop and evaluate a nano-microbicide containing a combination of cellulose acetate phthalate (HIV-1 entry inhibitor) and efavirenz (anti-HIV agent) for HIV prophylaxis. Cellulose acetate phthalate-efavirenz combination nanoparticles (CAP-EFV-NPs) were fabricated by the nanoprecipitation method and were characterized for particle size, zeta potential and encapsulation efficiency of efavirenz. CAP-EFV-NPs were incorporated into a thermosensitive gel (CAP-EFV-NP-Gel). CAP-EFV-NPs, CAP-EFV-NP-Gel and efavirenz solution were evaluated for cytotoxicity to HeLa cells and for in vitro short-term (1-day) and long-term (3-day) prophylaxis against HIV-1 infection in TZM-bl cells. CAP-EFV-NPs had size < 100 nm, negative surface charge and encapsulation efficiency of efavirenz was > 98%. CAP-EFV-NPs and CAP-EFV-NP-Gel were significantly less …