Manufacturing Organs

One of the big ethical questions of our time is focused on the debate over stem-cell research. Few lines of medical research have shown such promise to treat or cure a variety of chronic illnesses as stem-cell research. Some proponents have overblown its potential, but nonetheless, it's easy to reasonably draw the conclusion that stem-cell research could lead to treatments for Type I diabetes, paralysis and many degenerative diseases.

But ethics remains the big roadblock to research. And many of the ethical concerns are actually moral issues based on a poor understanding of the science involved. Many raise religious objections when an embryo is destroyed to harvest stem cells. Folks with these objections typically don't have a problem with using adult stem cells, but adult stem cells have not been found to be as adaptable as embryonic stem cells.

This week in Slate, William Saletan tackles a very interesting line of research that promises to really slap people in the face with ethical questions. In his series, The Organ Factory, Saletan examines how stem cells differentiate into the various organs of the body. If you can coax stem cells into forming, say, pancreatic islet cells, you can maybe transplant those into a diabetic, potentially curing their disease. But researchers have found that it is exceedingly difficult to successfully cause this differentiation in vitro, or, basically, in the lab. You can easily do it, however, in vivo -- when the cells are still in an embryo. In animal experiments, researchers have successfully grown differentiated stem cells and transplanted those cells when they've been grown in the embryo. Much less success for test tube differentiation.

Part one of the series describes the process while hinting at some of the ethical problems to come. Part two further explores the differences between in vitro and in vivo cell growth. The ethical problem still looms, and Saletan promises to get to it. In short, to cure someone of a chronic disease, would it be OK to create an embryo using their cells (a clone), let it grow for six or seven weeks, and then destroy it to harvest the tissues needed for the cure? As Saletan states, we already permit this, from an ethics standpoint, for the first two weeks. Why stop there?