Using cells from donated tissue or stem cells , Organovo is developing what it hopes will be authentic models of human organs , primarily livers , for drug testing . These printers will someday be producing complex -- and controversial -- human organs . Their precise design will create vascular systems required to make organs viable . Doctor : ` ` It has the potential for being a very important breakthrough '' Researcher : This will become a major ethical issue by 2016 .
These printers will someday be producing complex -- and controversial -- human organs . Their precise design will create vascular systems required to make organs viable . Doctor : ` ` It has the potential for being a very important breakthrough '' Researcher : This will become a major ethical issue by 2016 .