This week, researchers in at University of Texas Medical Branch were able to show that they could produce an artificially grown lung and successfully transplant it into a mammal. Lungs were grown in the laboratory from cells from the very same pig into which the organ would later be transplanted. The procedure was tested in 4 pigs, of which one lived for 2 months with a functioning transplanted lung.
Transplantation medicine is not something I know very much about, but from being involved in the ethical discussion of both animal research and gene editing, I come across the question every now and then. To me, there seems to be two routes that are being researched at the moment: engineering animals to make xenotransplantation safer and developing the techniques to grow organs in the laboratory from cells originating in the individual who needs a new organ. The Texas team used the second approach. In the discussion of how to put the genome editing tool CRISPR to best use, xenotransplantation is often mentioned as a worthwhile objective to pursue.
It’s in the nature of research that people work on different applications for a similar purpose – in this case a way to produce organs for transplantation which will relieve transplantation medicine from the reliance on human organ donors. At this point nobody is able to tell which route will take us to the goal first. But from the perspective of the 3Rs and especially Replacement, the artificially-grown-organ approach is much more appealing. Even though animal experiments will be used in the development of the method, once it’s considered safe there will be no more need to use animals. Xenotransplantation on the other hand will mean a continued use of animals, which will be bred and kept for the purpose of providing organs for human transplantation.