Heart-like tissue produced by 3D printing

MIT Technology Review : Growing simple tissues on 3D lattices in the lab is relatively easy. The muscle structure of heart tissue, however, is highly ordered and presents a bigger challenge. Martin Kolewe of MIT, Lisa Freed of Draper Laboratory, and their colleagues have adapted a machine for printing integrated circuits to create a lattice structure that allows the forming of tightly bound heart-like tissue. They used the machine to layer sheets of polymer biorubber that were patterned with a system of microscopic, rectangular holes. The researchers used a computer to align the holes in each layer, then they tested numerous patterns and found arrangements that produced the desired structure. The resulting bundled cells showed a contraction response to electrical stimulation, and the researchers could control the orientation of the growth of the bundles. However, before the tissue can be used in implant procedures, it will have to be grown thicker, with some sort of vascular system to provide blood to maintain the life of the cells, and engineered to mimic the specific behavior of the cardiac tissue.