A prosthetic heart valve provided herein can include a cultured cell tissue leaflet. In some cases, a prosthetic heart valve can include a plurality of leaflets secured together and retained within the expandable tubular member. The cultured cell tissue can be obtained by culturing fibroblast cells, smooth muscle cells, or a combination thereof to form a sheet of cultured cells and chemically cross-linking the fibroblast cells while under tension. In some cases, the cultured cell tissue can be radially tensioned. In some cases, the cultured cell tissue can be bi-axially tensioned.