Valves cardiaques par génie tissulaire : simplification des essais et concept tubulaire
|Advisor:||Ruel, Jean; Auger, François A.|
|Abstract:||High hopes are placed on tissue engineered heart valves to circumvent the restricted availability of allografts, the coagulation risks caused by mechanical valves and the limited durability of pericardial bioprostheses. With the self-assembly method, the only support for the cells is the extracellular matrix they themselves produce, allowing the tissue to be completely free from exogenous materials during its entire fabrication cycle. The project was preceded by those of the doctorate students Catherine Tremblay and Véronique Laterreur, who developed a new method to produce auto-assembled molded valves and a new version of the bioreactor used by our group, respectively. During this master, the new bioreactor has been adapted to a sterile use with living tissues and the molded valves method has been modified and tested with the production of 4 prototypes, which didn't provide satisfying results during their bioreactor trials. A new fabrication method was thus developed. Recently, the tubular shape has been suggested as a simple and effective geometry for tissue engineered heart valves, allowing easy fabrication, fast implantation, and minimal crimped footprint from a transcatheter delivery perspective. This minimalistic design is also well-suited for the self-assembly method, which has already proven its potential for small diameter vascular grafts. A total of 11 tubular constructs were produced by rolling self-assembled human fibroblastic sheets on solid mandrels. After maturation, the tissues were transferred onto smaller diameter mandrels to allow their free contraction. The characterization of two control tubes revealed that while preventing further contraction in the bioreactor, this precontraction phase was also beneficial for the tissue properties. The final prototypes could withstand a physiological pulmonary flow. This new method shows that the self-assembly process could be used to achieve functional tubular heart valves.|
|Document Type:||Mémoire de maîtrise|
|Open Access Date:||24 April 2018|
|Collection:||Thèses et mémoires|
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