By Tal Dvir
As tissue engineers, we seek to develop functioning substitutes for damaged tissues and organs. Generally, this means seeding cells onto 3-dimensional porous scaffolds made of biomaterials, which provide mechanical support and instructive cues for the developing engineered tissue. Now it’s time to go to the next level, and make complex tissues that can really do things (PDF) — contract, release growth factors, conduct electrical signals and more. Things our own cells and tissues do.