From the MIT Technology Review: "Cells coated with sticky bits of DNA can self-assemble into functional three-dimensional microstructures. ... Unlike top-down methods, in which scientists build cell structures on scaffolds, the new technique allows tissue engineers to dictate the precise geometric interactions of individual cells. ... So far these microstructures are rudimentary - far from the structural sophistication of a whole organ. But by tweaking the ratio of cell types, the density of DNA on the cells' surfaces, and the complexity of the DNA sequences, [researchers] hope to build larger and more intricate assemblies. ... even if this technique turns out not to scale up well [it] could in principle provide structural building blocks for use in other emerging bottom-up approaches, such as layer-by-layer tissue printing or laser manipulation. ... It has a lot of potential, and it may provide therapies in the future, but other challenges need to be overcome to make a clinically viable product."