Page 122 - Tailoring Electrospinning Techniques for Regenerative Medicine - Marc Simonet

CHAPTER 6
6.1 Abstract
For in-situ tissue engineering of heart valves, sca olds with appropriate biomechanical and spatial structures are required to assure and enable immediate functionality, durability and cellular infiltration. By choosing a fatigue resistant material and by adapting a proven valve design, this study demonstrates that electrospun heart valves are promising for in-situ tissue engineering. A sterile supramolecular polymer (PCL2kU4Un) was compared to poly(ε-caprolactone) (PCL) as material for in- situ tissue engineering of heart valves. Materials were electrospun and characterized with Scanning Electron Microscopy (SEM) and durability tests by fatigue testing at 10% elongation up to 3 million cycles. The hemodynamic performance and the functionality of corresponding electrospun valves were measured in a pulse duplicator under elevated
pulmonary pressures (50/25 mmHg) and aortic pressures (120/80 mmHg) at a cardiac output of 5 l/ min and heart rate of 70 bpm for 20 hours. The most promising electrospun heart valve prostheses were implanted in a sheep model replacing the pulmonary valve (n=10). In-vivo results showed immediate functionality of the implanted prostheses, as well as cellular infiltration with subsequent collagen production up to 5 weeks. However due to too fast degradation of the sca old, the valves failed a er 4 to 5 weeks. Despite the required improvement of the degradation characteristics of the polymeric valve, this study shows that in-situ tissue engineering of heart valves by electrospun polymeric sca olds is a promising approach toward a living heart valve prosthesis.
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