Since the first live kidney transplant in 1954, medicine has progressed tremendously and has made organ transplantation in hospitals a routine procedure. Despite this, there remains a massive shortage of organs for use meaning that many who desperately need to do the old organ switcheroo never come off the waiting list.
The field of regenerative medicine is attempting to change this. It comes is three main flavours, stem cells, scaffolds or both! Stem cells (those with the ability to become almost any other type of body cell) are becoming increasingly attractive in the use of Type 1 Diabetes treatment, where defective pancreatic cells can be replaced with stem cells (from the same patient) that have been programmed to produce the insulin that the body needs. Well in theory that’s how it works, in practice it’s a little more complicated.
Scaffolds are useful tools when engineering hollow structures like the trachea (windpipe). Using cells of the same type, a tissue-engineered replica replacement can be designed and inserted into the patient. Scaffolds, however, are more effective when combined with stem cells. By coating the structure with stem cells, the risk of rejection is decreased as the body accepts the implant as one of its own.
One of the coolest things to come from all of this is the idea that we may be closer than you think to actually being able to PRINT our own organs! How crazy is that?! 3D printing might allow us to make the previously unthinkable leap from transplant to growth to manufacture of organs. Ground-breaking work by Prof. Anthony Atala and colleagues at the Wake Forest Institute for Regenerative Medicine in the U.S. have taken this concept and given it a big old shove from science fiction into a hopefully real world prospect. Atala was able to print a small two-chamber heart using a modified desktop inkjet printer. But instead of ink in the cartridge, there were cells.
He was also able to print a miniaturised human kidney! Far from being full-sized, fully-functioning, transplantable organs that were created, this reveals that bio-printing it still in its infancy. It’s hoped that 3D printing will allow scientists to print stem cells, vessels, skin and even bone. By building up these tissues and structures one layer at a time, in combination with a specialised plastic gel, a useful, realistic model can be produced.
We may, one day, be at the point where we can go from printing sections of organs to printing organs as a whole. But as the biological complexity of the organ increase, they get more and more tricky to print. There’s also the problem of how the printed organ integrates with other systems of the body in terms of blood flow, for example.
It might be the case that when future generations go to hospital with unhealthy hearts or a kidneys that have kicked it, that they can simply get a specifically made replacement organ there and then. I kid you not, plans are being made for equipment that scans up and down the body to get the right scale and size, and then print a new organ directly into your body.
With plummeting costs of 3D printing, hopefully I’ll be able to put a 3D bio-printer on my Christmas list one day…
Xu T, Binder KW, Albanna MZ, Dice D, Zhao W, Yoo JJ, & Atala A (2013). Hybrid printing of mechanically and biologically improved constructs for cartilage tissue engineering applications. Biofabrication, 5 (1) PMID: 23172542
Image 1 adapted from http://littlemissmocha.com/2012/11/29/making-a-list-checking-it-twice-with-fisher-price/
Image 2 from http://www.popsci.com/science/article/2011-03/tissue-engineer-prints-replacement-kidney-onstage-ted-2011