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Full-Text Articles in Engineering

Laminin-Mimetic Peptide-Functionalized Hydrogel Systems For The Phenotypic Modulation Of Cells Of The Nucleus Pulposus, Marcos Nicolas Barcellona May 2021

Laminin-Mimetic Peptide-Functionalized Hydrogel Systems For The Phenotypic Modulation Of Cells Of The Nucleus Pulposus, Marcos Nicolas Barcellona

McKelvey School of Engineering Theses & Dissertations

The intervertebral disc (IVD) has been widely observed to undergo significant structural and biochemical changes with age and maturation. As degeneration progresses, changes in extracellular matrix composition and deposition, tissue cellularity, and metabolic activity have been characterized. Although the epidemiology of disc degeneration remains unclear, it is believed that the nucleus pulposus (NP) region of the IVD may be implicated in early degeneration. Specifically, cells of the nucleus pulposus have been observed to undergo a shift from their notochordal-like juvenile phenotype to a more fibroblast-like state in a manner concomitant to degenerative events. Because the disc has inherently little capacity …


Engineering Nucleus Pulposus Cell-Matrix Interactions With Laminin Ligands For Tissue Regeneration, Julie Elizabeth Speer May 2021

Engineering Nucleus Pulposus Cell-Matrix Interactions With Laminin Ligands For Tissue Regeneration, Julie Elizabeth Speer

McKelvey School of Engineering Theses & Dissertations

Low back pain and degenerative conditions of the intervertebral disc (IVD) represent major global socioeconomic and medical burdens. The structures that comprise the IVD including the anulus fibrosis and the nucleus pulposus (NP) work together to stabilize the axial skeleton and distribute mechanical forces. However, the degenerative cascade, which is thought to begin with changes to the NP, results in alterations to the disc that can be seen across length scales including elongated cell shapes, tissue dehydration, and loss of disc height. Patients who present clinically with these changes may also experience altered biomechanics, pain upon motion, impairments to their …


Ph-Sensitive Oxygen Release Microspheres To Enhance Cell Survival In Ischemic Condition, Zhongting Liu Dec 2019

Ph-Sensitive Oxygen Release Microspheres To Enhance Cell Survival In Ischemic Condition, Zhongting Liu

McKelvey School of Engineering Theses & Dissertations

Ischemic diseases such as myocardial infarction, stroke and limb ischemia are severe cardiovascular diseases with high rate of death and millions of people suffered from these diseases. Under ischemic environment, cells die due to deficient supply of nutrient and oxygen. To regenerate ischemic tissues, stem cell therapy is a promising approach because stem cells can differentiate into cells necessary for the regeneration. However, stem cell therapy has limitations. For example, few cells can survive under harsh ischemic environment. To enhance stem cells survival, implantation of oxygen release microspheres to sustained supply cells with oxygen represents an effective strategy. Previously, our …


Improved Orthopaedic Repairs Through Mechanically Optimized, Adhesive Biomaterials, Stephen Wheeler Linderman May 2019

Improved Orthopaedic Repairs Through Mechanically Optimized, Adhesive Biomaterials, Stephen Wheeler Linderman

McKelvey School of Engineering Theses & Dissertations

Despite countless surgical advances over the last several decades refining surgical approaches, repair techniques, and tools to treat tendon and tendon-to-bone injuries, we are still left with repair solutions that rely on fairly crude underlying mechanical principles. Musculoskeletal soft tissues have evolved to transfer high loads by optimizing stress distribution profiles across the tissue at each length scale. However, instead of mimicking these natural load transfer mechanisms, conventional suture approaches are limited by high load transfer across only a small number of anchor points within tissue. This leads to stress concentrations at anchor points that often cause repair failure as …


Elucidating The Roles Of Astrocyte-Derived Factors In Recovery And Regeneration Following Spinal Cord Injury, Russell E. Thompson May 2019

Elucidating The Roles Of Astrocyte-Derived Factors In Recovery And Regeneration Following Spinal Cord Injury, Russell E. Thompson

McKelvey School of Engineering Theses & Dissertations

Central nervous system (CNS) injury often causes some level of long-term functional deficit, due to the limited regenerative potential of the CNS, that results in a decreased quality of life for patients. CNS regeneration is inhibited partly by the development of a glial scar following insult that is inhibitory to axonal growth. The major cell population responsible for the formation this glial scar are astrocytes, which has led to the belief that astrocytes are primarily inhibitory following injury. Recent work has challenged this conclusion, finding that astrocyte reactivity is heterogeneous and that some astrocytes are pro-regenerative following injury. Astrocyte transplantation …


Synthesis Of Clickable Poly(Ethylene Glycol) Derivatives For Fabrication Of Modular Microsphere-Based Scaffolds To Promote Vascularization, Peter Nguyen Aug 2015

Synthesis Of Clickable Poly(Ethylene Glycol) Derivatives For Fabrication Of Modular Microsphere-Based Scaffolds To Promote Vascularization, Peter Nguyen

McKelvey School of Engineering Theses & Dissertations

Vascularization plays an important role in supporting transplanted tissues and cells in tissue engineering applications. Most tissues require access to blood vessels for the delivery of oxygen and nutrients, as well as the removal of carbon dioxide and cellular waste products. Without an adequate blood supply, cells within tissue-engineered constructs and scaffolds lose viability and fail to perform their intended functions. The goal of this dissertation was to design scaffolds that can promote vascularization of biomaterial implants for biomedical applications. In order to accomplish this goal, clickable poly(ethylene glycol) (PEG) derivatives were synthesized in order to fabricate modular microsphere-based scaffolds …


Sustained Dual Drug Delivery Of Anti-Inhibitory Molecules For Spinal Cord Injury Treatment, Thomas Wilems Aug 2015

Sustained Dual Drug Delivery Of Anti-Inhibitory Molecules For Spinal Cord Injury Treatment, Thomas Wilems

McKelvey School of Engineering Theses & Dissertations

Regeneration of lost synaptic connections following spinal cord injury (SCI) is limited due to local ischemia, cell death, and an excitotoxic environment, which leads to the development of an inhibitory glial scar surrounding a cystic cavity. Myelin-associated inhibitors (MAIs) and chondroitin sulfate proteoglycans (CSPGs) are major inhibitors to axon growth inhibition found within the glial scar and limit functional recovery. The NEP1-40 peptide competitively binds the Nogo receptor and partially blocks inhibition from MAIs, while chondroitinase ABC (ChABC) enzymatically digests CSPGs, which are upregulated at the site of injury. The first part of this work develops drug delivery systems which …


Engineering Poly(Ethylene Glycol) Materials To Promote Cardiogenesis, Amanda Walker Smith Aug 2013

Engineering Poly(Ethylene Glycol) Materials To Promote Cardiogenesis, Amanda Walker Smith

McKelvey School of Engineering Theses & Dissertations

Heart failure is one of the leading causes of death worldwide, and the current costs of treatment put a significant economic burden on our societies. After an infarction, fibrotic tissue begins to form as part of the heart failure cascade. Current options to slow this process include a wide range of pharmaceutical agents, and ultimately the patient may require a heart transplant. Innovative treatment approaches are needed to bring down costs and improve quality of life. The possibility of regenerating or replacing damaged tissue with healthy cardiomyocytes is generating considerable excitement, but there are still many obstacles to overcome. First, …