Heart valve

A heart valve having at least a portion thereof constructed from a block-copolymer having at least first constituent blocks and second constituent blocks, the block-copolymer having first phase structures formed by the first constituent blocks and a second phase structure formed by the second constituent blocks,

• wherein the first and second phase structures are arranged so as to produce anisotropic physical properties in the at least the portion of the heart valve constructed of the block copolymer,
• the first phase structures formed by the first constituent blocks are dispersed throughout the second phase structure formed by the second constituent blocks, the second phase structure defining a total thickness of the portion of the heart valve,
• a first group of the first phase structures formed by the first constituent blocks are dispersed in the second phase structure such that each of the first phase structures of the first group are aligned in a first direction, and a second group of the first phase structures formed by the first constituent blocks are dispersed in the second phase structure such that each of the first phase structures of the second group are aligned in a second direction that is different from the first direction, and
• the first group is located throughout a first thickness of the total thickness of the second phase structure, and the second group is located throughout a second and separate thickness of the total thickness of the second phase structure.