First, you pour a thick liquid chemical over a wad of cotton candy. Let the liquid solidify into a chunk, and put that in warm water to dissolve the candy. That leaves tiny channels where the strands of candy used to be. So you have a chunk of material with a network of fine channels within.
Next, line these channels with cells to create artificial blood vessels. And seed the solid chunk with immature cells of whatever tissue you're trying to make. The block is biodegradable, and as it disappears, it will gradually be replaced by growing tissue. In the end, you get a piece of tissue permeated with tiny blood vessels.
The research was done by Dr. Jason Spector of NewYork-Presbyterian Hospital and Leon Bellan of Cornell University. Spector enjoys cotton candy, but Bellan finds it disgusting. Link -via Geek Like Me
(image credit: Flickr user Indrani Soemardjan)