Biomedical Engineering and Bioengineering Commons^™

Experimental And Theoretical Studies Of Native And Engineered Vascular Tissue Mechanics, Boran Zhou

Theses and Dissertations

Background: Implantation of vascular grafts provides a means to restore blood flow in compromised regions of the circulatory system, and thus is used to treat a wide range of cardiovascular diseases. Despite significant advancements in autologous grafting strategies as well as the engineering of synthetic alternatives, mechanical, structural, and compositional incongruities between the graft and the host artery remain as contributing factors to graft failure. The typical failure modality manifests as proximal anastomotic intimal hyperplasia, which places restrictions on the host vessel size currently treated with grafting strategies (> 5 mm internal diameter). In order to improve long-term clinical outcomes, …

A Three-Dimensional In Vitromodel Of Atherogenesis, Pin Hsuan Chang

Theses and Dissertations

Atherosclerosis is the narrowing of arteries caused by accumulation of cholesterol, calcium and other cellular debris in the inner arterial wall. While extensive studies have been focusing on the inflammatory mechanisms of the disease, pathological and experimental evidence has shown that regions of disturbed flow are susceptible to the atherogenesis. To further understand the relationship between hemodynamics and atherogenesis, this research aims to generate a dynamic, 3D in vitro model of atherogenesis. This will allow for the investigation of specific cellular and molecular mechanisms of plaque formation that will pave the way for new therapies for the disease. A novel …

Developing A Bioreactor For Biaxial Mechanical Testing And Conditioning Of Vascular Tissue, Steve Marcous

Theses and Dissertations

Cardiovascular diseases are known to be one of the major causes of death around the world. One of the major causes of cardiovascular disease is arterial malfunction. Arteries malfunction when they experience chronic perturbations in their local environment above normal levels. Hence, we developed a bioreactor system in order to study the effect of chronic changes in the arterial global parameters (axial force, luminal pressure, and flow rate) on the behavior of local parameters (circumferential stress, axial stress, and flow induced shear stress). The bioreactor system was designed to (i) perform biaxial mechanical testing, (ii) incorporate, for the first time, …

Novel Conditioning Protocols Focusing On Oxygen Manipulation To Enhance Stem Cell Transplantation, Brandon William Hanna

Theses and Dissertations

Musculoskeletal tissue engineering involves the creation of multiple tissue types that interact together to form a particular function related to motion and maintaining the body's frame. In order to create a fully functional musculoskeletal system, a concrete method for the creation of the different tissue types must first be completed. Of the different tissue components related to the function of a musculoskeletal system, these studies deal with preconditioning circumstances of stem cells that will differentiate into cartilage and bone. These studies also deal with methods for the creation of functional bone and cartilage to be combined for the creation of …

Isolation Of Natural Nrf2 Activators From American Ginseng, Akrm Abdalrahman

Theses and Dissertations

Nuclear factor erythroid-2 related factor 2 (Nrf2), a major transcription factor of the endogenous antioxidant defense system, has been proposed as a potential therapeutic target for the treatment of various diseases. However, a small molecule-driven Nrf2 signaling therapeutic approach remains to be established. Herein, we report one such possibility discovered by the bioassay-based fractionation of American ginseng. Since crude extract of American ginseng was found to suppress the expression of inducible nitric oxide synthase (iNOS) in lipopolysaccharide (LPS)-inflamed macrophages via activating Nrf2, we further fractioned the crude extract using solvents including hexane, dichloromethane, ethyl acetate, butanol, and water, and found …

Identifying Performance Criteria Of Fully Bioresorbable Scaffolds For Endovascular Applications, Jahid Ferdous

Theses and Dissertations

Background: Bioresorbable scaffolds (BRS) have revolutionized percutaneous coronary intervention in clinical cardiovascular medicine. As opposed to permanent alternatives such as metallic stents, BRS have an inherent potential to reduce the occurrence of untoward events such as vessel re-narrowing or thrombosis by virtue of undergoing complete and controlled resorption post- implantation. While BRS platforms demonstrate a clear potential to mitigate risk stemming from incomplete vessel healing, they introduce a new set of considerations to clinical safety and efficacy. Foremost among these issues is the fate of and biological response to material by-products that evolve throughout the scaffold degradation and erosion processes, …

Discovery And Characterization Of Multi-Target Directed Ligands As Inhibitors Of Amyloid-Β Aggregation And Regulators Of Alzheimer's Disease, Jui-Heng Tseng

Theses and Dissertations

Alzheimer's disease (AD) is the most common neurodegenerative disease in the world. As the disease advances, symptoms include confusion, language skill breakdown, and long term memory loss - and culminate in death. Existing therapies for AD provide symptomatic benefits but cannot halt or slow the disease pathogenesis.

Increasing evidence reveals the multi-factorial nature of AD. Numerous factors, including amyloid-β (Aβ) aggregation, calcium homeostasis dysregulation, and oxidative stress, contribute to disease development and interplay with each other. Therefore, multi-target directed ligands (MTDLs) may present an effective AD treatment. Among all factors, Aβ aggregation is suggested to play the most crucial role. …