Development of a novel synthetic leaflet heart valve using a new nanocomposite material and stem cell technology

Heart valve replacements are among the most widely used cardiovascular devices and are in rising demand. Currently, clinically available devices are restricted to the mechanical and bioprosthetic valves which are associated with significant complications and drawbacks. Synthetic leaflet heart valves based on newly emerged superior materials represent an attractive alternative to the existing prostheses, merging superior durability of mechanical valves and enhanced hemodynamic function of bioprosthetic valves. A new nanocomposite polymer based on polyhedral oligomeric silsesquioxane (POSS) and poly(carbonate-urea)urethane (POSS-PCU) has been developed for biomedical application. In this thesis, application of POSSPCU for development of a novel synthetic leaflet heart valve has been fully investigated. Mechanical and surface properties of this material in both room and body temperature were investigated as well as durability, fatigue properties, and anticalcification potential under accelerated physiological condition. Endothelialisation potential of the polymer was also elicited by isolation, characterisation and culture of endothelial progenitor stem cells extracted from human peripheral and umbilical cord blood. Haemocompatibility of the material was evaluated in terms of thrombogenenicity, palatelet activation and induced inflammatory response. Based on the favourable outcomes of these experiments, a novel trileaflet valve prosthesis was developed using advanced design and manufacturing strategies. The valve prototypes were then assessed in terms of hydrodynamic performance using a pulse duplicator system. The results indicate that POSS-PCU nanocomposite is an optimal material to be used in the fabrication of new generation synthetic leaflet heart valves with enhanced durability and superior performance