One of the most interesting articles I've read in quite a while is a piece by Dr. Konrad Hochedlinger, associate professor of stem cell and regenerative biology at Harvard Medical School.

The article appeared in the May 2010 issue of Scientific American.

In the article, Dr. Hochedlinger described the work of a number of researchers, including Shinya Yamanaka at the University of Kyoto.

Essentially, the issue that has hampered most of stem cell research is this: embryonic stem cells, while potent and capable of differentiation into any type of adult tissue, are fraught with ethical concerns.

What Drs Yamanaka and Hochedlinger have demonstrated is the ability to take adult cells that have fully differentiated into different organ systems and by using special techniques, returned these cells to the early embryonic stem cell phase. How cool is that!

The magnitude of the problem they have overcome cannot be underestimated. The normal sequence of events in the development of human beings is that as you grow in utero, your body is made up of early embryonic cells.

Early embryonic cells are pluripotential, meaning they can become any type of tissue, given the right set of circumstances. As you mature in utero, you reach the late embryo stage. At that point, your stem cells are transitioning from being pluripotential to becoming multipotential, which means they can become cells of a specific tissue type but not any tissue type.

And by the time you are ready to pop out of the womb, your stem cells have become adult stem cells, they are still multipotential but not pluripotential.

Now what these scientists have brilliantly done is to use nonpathogenic viruses (viruses that don't cause disease) as delivery messengers to carry genes into fully differentiated adult cells and reprogram them so they become pluripotential stem cells. They are now called "induced pluripotential stem cells." Unbelievable!

So how will this new technology be of use?

First, the author stated that they can use these induced pluripotential stem cells to study disease. If they take cells from a sick patient and convert them into pluripotential stem cells, they can get an insight into disease progression.

Second, by converting induced pluripotential stem cells taken from a sick person into healthy cells, they can deliver healthy cells back to that patient.

Obviously, the most exciting use is the possibility of taking these induced pluripotential stem cells and using them to generate new healthy tissue and replace damaged or diseased tissue. Another possibility is using these stem cells to correct genetic mutations.

The concerns regarding this research though are many. Not all induced pluripotential cells are effective. Some may not have received the entire proper genetic coding sequence.

Second, in some animal models, scientists have been able to get good control of disease but at the same time, unwanted side effects have appeared.

Much of the research is still being done in the lab where special culture plates, called petri dishes are being used to create models of disease. Hopefully, these models will aid in developing new medicines for disease. Dr. Hochedlinger raises other concerns about whether the process of creating induced pluripotential cells will ever be efficient enough to enable these cells to be used widely.

Also, there are concerns that some retained memory from before conversion into induced pluripotential stem cells might limit the use of these cells. And finally, induced pluripotential stem cells are capable of generating a new human embryo. This raises severe ethical concerns.

Nonetheless, the promise of this technology is such- particularly when it comes to arthritis- that I was thrilled to see it. Cartilage is difficult to grow because of lack of vascularity. There are no blood vessels to carry nutrients to damaged cartilage. It will be up to new technologies to repair and replace cartilage.

Still, our work at the Arthritis Treatment Center with autologous adult mesenchymal stem cells, and this new basic science with induced pluripotential stem cells look very promising. Stay tuned for more developments.