Date of Graduation

5-2026

Document Type

Thesis

Degree Name

Bachelor of Science in Biomedical Engineering

Degree Level

Undergraduate

Department

Biomedical Engineering

Advisor/Mentor

Morten Jensen

Abstract

Partial heart transplantation (PHT) has spurred a paradigm shift in the field of pediatric valve replacement that allows for children to receive a growing heart valve that prevents reoperations. A major barrier to the widespread adoption of PHT is the logistical constraints of procurement and the lack of supply. Methods to store valves for long periods of time could help alleviate these concerns by providing off the shelf solutions, and also ensure that no potential donor tissue is wasted. Vitrification has emerged as a potential storage method that could allow for months-long storage of the grafts. Porcine pulmonary (n = 13) and aortic valves (n = 13) were harvested and vitrified for 7 (n = 5), 30 (n = 6), or 90 (n = 2) days and then tested. In order to investigate changes in tissue properties and cellular viability, tensile testing, histology, and alamarBlue testing was performed. Histology shows no differences between healthy control tissue and 30 day vitrified tissue, with preserved cellular composition and extracellular matrix structure of all three levels. Viability as measured through alamarBlue assay shows meaningful recovery for both 7 and 30 day vitrification tissue, while 90 day tissue did not meaningfully recover over the three day period. Tensile testing revealed that vitrified tissue did not change significantly between 7 and 30 days of vitrification, indicating that extended storage of tissue should not diminish hemodynamic performance or durability of tissue. Overall, this study provides support that extended periods of storage are possible through vitrification, pre-clinical animal models demonstrating the capacity for growth would further build support for the clinical implementation of vitrification for extended storage of PHT valves.

Keywords

Partial Heart Transplantation; Transplantation; Biomechanics; Heart valve replacement; Cardiac Surgery

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