For the uninitiated, 3D printing is a fast-growing manufacturing technology that effectively allows "printing" of small objects like machinery components. Where the "revolution" part comes into play is that the "printers" are small enough and inexpensive enough to let almost anyone set up a mini-factory in their garage - or laboratories. These mini-factories are connected to a computer where 3D models are designed and fed into the printer (along with the necessary raw materials). Using high-powered lasers, the printer shapes the object according to the specifications.
Last December I wrote about Organovo - a 3D bioprinting company that was partnering with Autodesk to print living, architecturally correct human tissue. A new, potentially more exciting development is that researchers from the University of Edinburgh have developed a printer that is able to produce living, viable, embryonic stem cells. For those suffering from chronic diseases like Alzheimer's or Multiple Sclerosis - this has the potential to be life-changing.
While most adult tissue has its own stem cells, embryonic stem cells are unique - they are able to differentiate into almost any type of tissue to repair it after it has been damaged. In recent years, however, there's been quite a bit of controversy surrounding the ethics of using embryonic stem cells (which have to be harvested from human embryos), to say nothing of the possibility of rejection when injecting stem cells from one person into another.
While these issues remain, the ability to spit out these stem cells through a simple manufacturing process (the printer doesn't technically manufacture the cells - it clumps them into uniform droplets to keep them viable using two types of "bio-ink") provides a new, automated way of producing embryoid bodies (essentially a clump of stem cells) that can be used in treatments. And indeed, an ever growing body of research is indicating that stem cell treatments - even those derived from a person's own body (non-embryonic) may help to cure (not only treat) chronic diseases like MS.
Of course, any optimism should be tempered with reality. Printing stem cells that have biomarkers indicating pluripotency (the ability of a stem cell to differentiate into any type of cell) is very different from using those same cells to treat diseases in humans. It's unclear whether the human body will be able to accept these manufactured stem cells or how viable they will be in the long-run compared to natural stem cells.
There are also potential regulatory pitfalls. The FDA has been less than accommodating to companies that have tried using autologous stem cell treatments (where stem cells are taken out of a person, treated, and injected back into the same person), shutting down the laboratory of a promising venture in 2012. Though the FDA has a specific statute under which they regulate human cells and tissues, these newly manufactured cells would likely not fall under that statute. Instead, a company would probably need to pursue approval as a drug - but the long, winding, and expensive process of clinical trials is poorly suited to proving the ability of stem cells in treating chronic diseases.
A more stem-cell-friendly approach would allow companies offering these treatments to conduct "N=1" trials - for patients who have decided that an unproven treatment may very well be worth it if it has the possibility of curing a disease like MS - and submit this data over time to the FDA to help prove the efficacy of the treatment as well as to potentially help validate new surrogate endpoints.