The Potential of Prolonged Tissue Culture to Reduce Stress Generation and Retraction in Engineered Heart Valve Tissues

Heart valve tissue engineering (TE) relies on extracellular matrix production by cells seeded into a degrading scaffold material. Valves are cultured constraint with the leaflets attached to each other for 4 weeks [1]. The seeded cells naturally exert traction forces to their surroundings and due to an imbalance between scaffold, tissue and these traction forces, stress is generated within the tissue, which is good for tissue formation and architecture. However, during culture it causes tissue compaction, resulting in leaflet flattening, and at time of implantation, the leaflets are separated and the generated stress causes retraction of the leaflets (fig 1). This retraction on its turn results in loss of functionality.