The concept of growing new organs first cropped up in the scientific literature in the 1930s, said Anthony Atala, director of the Wake Forest Institute for Regenerative Medicine in Winston-Salem, North Carolina. Real-life applications, however, began to appear only more recently.
With bladders grown from the cells of sick children and teenagers, Atala's group was the first to successfully implant lab-grown organs into people, beginning in 1998. In a paper in the Lancet in 2006, the team reported the promising long-term results of those procedures.
According to Atala, researchers have been able to grow and implant three kinds of parts: flat tissues like skin, tubular structures like blood vessels, and hollow organs like stomachs and bladders.
The next frontier includes solid organs, such as hearts, livers and kidneys. These structures are particularly complicated to build because they contain many different kinds of cell types and they require lots of blood vessels to carry fluids in and out.