BASICS

Why Can’t We Regrow Organs Yet?

National Journal, 2013

“There are four levels of organ complexity, the first being flat surfaces like skin, the second hollow tubes like trachea, the third hollow structures, like the bladder and stomach, and the fourth solid structures, such as the liver and lungs. ‘Up to this point, we’ve been able to implant the first three types in patients,’ Atala says, ‘but we have not yet implanted solid structures in patients. That’s still years away.’”

Replacement Parts

The Scientist, 2012

“Today, the organ shortage is an even bigger problem than it was in the 1980s. In the United States alone, more than 114,000 people are on transplant lists, waiting for an act of tragedy or charity. Meanwhile, just 14,000 deceased and living donors give up organs for transplants each year. The supply has stagnated despite well-funded attempts to encourage donations, and demand is growing, especially as the organs of a longer-lived population wear out.”

The Great Stem Cell Dilemma

Fortune, 2012

“Treatments, not cures. This, in a nutshell, is the MO of our health care system, and it’s precisely the reason that regenerative medicine — and stem cell therapy in particular — has been the subject of so much hope and hype over the past decade or so. Stem cell therapies promise to empower a body to fight ailments by enabling it to build new parts.”

RECENT DEVELOPMENTS

Artificial Organs May Finally Get a Blood Supply

MIT Technology Review, 2014

“In recent years, researchers have made impressive progress in building tissues and organ-like structures in the lab. Thin artificial tissues, such as a trachea grown from a patient’s own cells, are already being used to treat patients . . . . But no matter the method of construction, all regenerative projects have run up against the same wall when trying to build thicker and more complex tissues: a lack of blood vessels.”

Miniature Human Liver Grown in Mice

Nature, 2013

“Takanori Takebe, a stem-cell biologist at Yokohama City University in Japan who co-led the study, believes this is the first time that people have made a solid organ using induced pluripotent stem cells, which are created by reprogramming mature skin cells to an embryo-like state.”

Lab-Grown Kidneys Transplanted Into Rats

Nature, 2013

“If [Ott] and his team can scale up their technique to produce human kidneys, they could provide ready-made, genetically tailored organs that would be much less likely to be rejected by a patient’s immune system. The scaffolds could come from existing donors — with no need for a genetic match — or perhaps even from animals, such as pigs. In some cases, bioengineers might be able to strip the patient’s own diseased kidney and rebuild it.”

Turning Lymph Nodes Into Liver-Growing Factories

Discover, 2012

“In many ways, lymph nodes are ideal bioreactors for growing new livers. They have an unusual capacity to expand, allowing them to accommodate an entire organ. They have ready access to the bloodstream, which nurtures new cells with nutrients as well as hormones and signaling agents needed for growth. And since the body has many lymph nodes, some can sacrifice their traditional duties to grow livers.”

IN DEPTH

Building Flesh and Blood

The Scientist, 2014

“One major obstacle keeping researchers from crafting functioning organs is the inability to ensure adequate blood supply to the nascent organ. Even if an entire organ can be constructed using all the appropriate cell types, its survival in the body depends on its access to oxygen and nutrients.”

Perspectives on Whole-Organ Assembly: Moving Toward Transplantation on Demand

Journal of Clinical Investigation, 2012

“The development of alternative sources of donor organs would change the paradigm of organ transplantation . . . . Here, we describe the current state of the art in organ engineering and provide perspective on the biological and engineering challenges that must be overcome to realize bioartificial organs. We highlight the need for appropriate sources of scaffolds and cells and to advance the understanding of neo-tissue development.”