Date of Award

8-2025

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Bioengineering

Committee Chair/Advisor

Dan Simionescu

Committee Member

Agneta Simionescu

Committee Member

Lee Sierad

Abstract

Cardiovascular disease is an extremely deadly disease that affects people throughout the world. It is the leading cause of death worldwide, affecting over a quarter of the population.1 Some forms of cardiovascular disease directly affect the heart valves and their function. Surgery or a replacement device are the most common current treatment options. These treatments are effective in addressing heart valve diseases in adults, but they are less effective when used for children patients. This creates a need to develop a solution for the child population.

Congenital heart defects are structural abnormalities that often lead to infant mortality.2,3 Pulmonary valves, the structure in the heart that allows blood flow from the heart to the lungs, do not always function the right way. These deformations affect about 40,000 patients every year.4,5 Many times when considering this specific disease, symptoms are treated as best as possible but the source of these symptoms cannot be fixed completely. Often times, open heart surgery is the only option and can be needed every few years. This causes extreme stress on the patient’s body. A newly designed replacement of the pulmonary valve is needed for the children suffering from these ailments.

The proposed solution is called the Expand ValveTM. The valve is created from animal tissue that is completely stripped of all native cells and DNA fragments. This tissue creates a scaffold that can be sewn onto a stent, or small mesh-like tube, to create a pulmonary valve. The valve is able to expand up to two times its original size. Chemicals are also used to increase the durability of the valve. Valve designs were tested by seeing how they functioned in bioreactors, which are systems or machines that mimic body conditions. Stem cells were injected into the valve that was placed in the bioreactor to determine if the cells could grow to create a living valve. We found that the process to remove the DNA from the animal tissue worked. The chemicals added to the tissue helped to increase its stiffness and overall strength. Larger leaflets allowed the valve to close more at bigger sizes. The injected cells grew into the valve and functioned when put in a simulated environment for the human body.

Download

Available for download on Monday, August 31, 2026

Share

COinS