Abstract 1064: Autologous Prosthetic Heart Valved-Conduits Developed by in vivo Tissue-Engineering
Background: As a practical concept of regenerative medicine, we address constructing autologous prosthetic substitutes by “in body tissue architecture technology”, utilizing the living body as a reactor for autologous tissue organization. Novel autologous valved-conduits were produced by creating the specially designed conduit-mold composite for this unique in vivo tissue-engineering.
Methods: Plastic molds for valvular leaflet organization, consisting of two pieces assembled with a small aperture of 500~800 μm, was inserted into a microporous elastomeric couduit scaffold (micropore size: 100 μm, penetrating laser-processed holes to induce rapid tissue infiltlation: 100 μm by 300 or 600 μm regular intervals by a computer assisted control, tubular diameter: 5 mm). The assembly was placed in the subcutaneous spaces of Japan white rabbits for 1 month. The molds were pulled out from the harvested implant to obtain the valved-conduit.
Results: Membranous tissues of a well-balanced tri-leaflet form were developed in the optimized aperture of molds. The leaflet tissues, primarily composed of fibroblasts and collagen-rich extracellular matrices, tightly connected with similar tissues ingrown into the interstices of the porous conduit scaffold. Tight valvular coaptation and sufficient open orifice area were observed in the pulsatile flow circuit in vitro.
Conclusions: A tissue-engineered conduit incorporated with a functional autologous tri-leaflet valve, which was developed in in vivo reactor by optimizing the microstructures of conduit scaffolds and newly designing the composite molds, could be a safe and economical prosthesis with excellent biocompatibilities.