Electrospun bioresorbable trileaflet heart valve prosthesis for tissue engineering: in vitro functional assessment of a pulmonary cardiac valve design.

SUMMARY Currently implanted prosthetic heart valves, both mechanical or biological ones, are used to restore the proper blood hemodynamics when the native valves fail. However, these medical devices are not free from drawbacks, such as hemolysis or calcification, also presenting the relevant disadvantage of being unable to growth, repair and remodel. An improvement could be represented by bioresorbable polymeric tissue-engineered heart valves. In this paper a poly(epsilon -caprolactone) (PCL) heart valve prosthesis, realized by means of electrospinning, and its in vitro functional characterization in a pulse duplicator, resembling pulmonary conditions, is presented. Morphological examination revealed polymeric micrometric fibers randomly oriented with an average porosity of about 90 percent. Pulse duplicator testing highlighted that leaflets opened synchronously and showed a correct coaptation in the diastolic phase, even if a slight rotation of the leaflets was visualized. In silico study by numerical simulation of the closed phase predicted the stress distribution within the leaflet, showing that peak levels are reached at the commissures and sustained by the structure without failure. The present study highlighted the technical feasibility to produce polymeric bioresorbable functional heart valves by means of electrospinning. Further studies and design changes are needed in order to optimize the final scaffold to bear arterial hemodynamic conditions.