While 3D printing is now regularly used to create models to help direct the work of surgeons taking on complex operations, a team of doctors and researchers in New York are working on tissue engineering to build the progenitors of what will one day become customized replacement organs and structures. Todd Goldstein and Dr. Daniel Grande have created a series of 3D printed tracheal segments they say will one day, following FDA approval, help doctors rebuild complicated portions of the human anatomy which use a patient's own cells and PLA as raw material. They are using a modified MakerBot Replicator 2X Experimental 3D printer in their work. You can read the whole story here: http://3dprint.com/40128/3d-printed-trachea/

Below is a photo of Dr. Daniel Grande (L) and Todd Goldstein (R) with their MakerBot 3D printer in the lab: