Fibringel als Scaffold für das Tissue Engineering von Herzklappen

This study’s goal was to optimize the molding technique for fibrin-based heart valves first described by Jockenhoevel et al. and to develop a bioreactor system for in-vitro culture of fibrin-based tissue engineered heart valves. The molding technique was simplified to allow for routine use and a bioreactor system for in-vitro culture was developed. The mould’s geometry were closely studied, just as the culture conditions in the bioreactor system. Thus, it was possible to produce sustainable tissue histologically mimicking native valve tissue. A system for endothelial cell coating was also developed. Following this dissertation, tissue-engineered semilunar heart valves were tested in sheep. We were able to perform implantation at the pulmonary position. The valves endured normal hemodynamic conditions for up to 3 months. Continuous control of quality of media is necessary to ensure adequate tissue development. Also following this work, on-line measuring of partial pressures for O2, CO2 were established. Future work will employ markers of tissue development as well as imaging technique for better control of the culture process to enhance the quality of tissue-engineered semilunar valves. Also, the mould’s geometry and culture conditions have to be further studied to enhance the valve’s geometry after culture. Further studies of the processes governing tissue engineering and a better understanding of influencing factors will foster our control of the development of engineered tissue. The advances will hopefully enhance the possibilities of heart valve replacement and improve the treatment of diseases of the heart valves, especially in children.