Andrew Lee, Andrew Hudson, Dan Shiwarski, Josh Tashman, TJ Hinton, Sai Yerneni, Jaci Bliley, Phil Campbell, and Adam Feinberg are co-authors on our recent article in Science entitled “3D bioprinting of collagen to rebuild components of the human heart.” In the article we report our second-generation of FRESH 3D bioprinting, using it to print collagen and cells in to functional tissues and components of the human heart, from vascular-like networks to small beating ventricles.