They had used a small piece of each patient's own tissue from the bladder, then grew the cells in a lab onto a mesh scaffold shaped like a urethra.

CNN: Lab-made organ implanted for first time

Germeshausen Professor of Chemical and Biomedical Engineering at MIT, is a founder of the budding field of tissue engineering--of restoring, maintaining and improving tissue by growing it, in vitro, on a biodegradable polymer (plastic) scaffold.

FORBES: Plastic Man