US Patent 9056006 Prosthetic heart valve formation

A prosthetic heart valve includes a base and a plurality of polymeric leaflets. Each leaflet has a root portion coupled to the base, and each leaflet has an edge portion substantially opposite the root portion and movable relative to the root portion to coapt with a respective edge portion of at least one of the other leaflets of the plurality of leaflets. Each leaflet includes) at least two polymers along at least one portion of the leaflet, and each leaflet has a composition gradient of each of the at least two polymers along at least one portion of the leaflet.