Biomedical Engineering and Bioengineering Commons^™

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 …

Nitric Oxide Expression With Age And Diet In The Arterial Wall Of Apoe Knockout Mice, Kara Cooper

Theses and Dissertations

Background: Hypertension is a dangerous condition that precedes many cardiovascular events including myocardial infarction, stroke, transient cerebral ischemic attack and symptomatic aortoiliac occlusive disease. While it is universally accepted that arteries stiffen with age, the physiological reason for this is debated. In a previous study, by Dr. Shana Roach Watson it was shown that collagen fibers re-orient themselves in a circumferential direction, resulting in increased arterial stiffness. The study hypothesized that this collagen remodeling could be a result of decreased nitric oxide production.

Methods: This study measured nitric oxide in two different ways, indirectly via Immunoperoxidase staining for eNOS and …

The Influence Of Passive Ankle Joint Power On Balance Recovery, Stephanie E. Hamilton

Dissertations, Master's Theses and Master's Reports - Open

Over one–third of Americans over the age of 65 fall each year, costing more than $19 billion in health care costs in 2000. Many adults 65+ who have not experienced a fall still fear falling, and fear can decrease quality of life and increase the likelihood of falls. Several factors such as muscle strength, power, stiffness and tendon properties change in the human body with age affecting balance, which has been tagged as a fall risk predictor. Additionally, balance recovery strategies also differ between young and older adults, with young adults primarily utilizing their ankle joint and older adults utilizing …

Ischemia Impairs Vasodilation In Skeletal Muscle Resistance Artery, Kyle Remington Struthers

Master's Theses

Functional vasodilation in arterioles is impaired with chronic ischemia. We sought to examine the impact of chronic ischemia and age on skeletal muscle resistance artery function. To examine the impact of chronic ischemia, the femoral artery was resected from young (2-3mo) and adult (6-7mo) mice and the profunda femoris artery diameter was measured at rest and following gracilis muscle contraction 14 days later using intravital microscopy. Functional vasodilation was significantly impaired in ischemic mice (14.4±4.6% vs. 137.8±14.3%, p<0.0001 n=8) and non-ischemic adult mice (103.0±9.4% vs. 137.8±14.3%, p=0.05 n=10). In order to analyze the cellular mechanisms of the impairment, a protocol was developed to apply pharmacological agents to the experimental preparation while maintaining tissue homeostasis. Endothelial and smooth muscle dependent vasodilation were impaired with ischemia, 39.6 ± 13.6% vs. 80.5 ± 11.4% and 43.0 ± 11.7% vs. 85.1 ± 10.5%, respectively. From this data, it can be supported that smooth muscle dysfunction is the reason for the observed impairment in arterial vasodilation.