The near future of organ transplants will become very varied, as a range of different viable types of technology are presently undergoing active development. A short list looks much like this:
- Incremental progress in old-style organ transplants, such as improving the donation system, allowing organs to be stored outside the body for longer periods of time, and so forth.
- Decellularization, in which a donor organ is stripped of cells, leaving only the scaffold of the extracellular matrix. The scaffold is repopulated from the patient's cells, removing the possibility of immune rejection and need for immunosuppressant drugs.
- Electromechanical and bioartificial organs, including hearts, lungs, and kidneys, continue to improve at a good pace. New types of small artificial organ are becoming possible thanks to advances in materials science.
- Creating organ tissue and scaffolds from scratch through a variety of methods, such as the 3-D printing pioneered by a number of groups.
- Xenotransplantation, the use of animal organs for human patients, is also becoming more viable as a near-term prospect.
- Lastly, there are the researchers who aim to rebuild damaged organs in situ through manipulation of stem cells and signaling processes in normal regeneration.
There will be a great deal of innovation and healthy competition over the next two decades before this larger cycle of technological progress in medicine settles down to a few mature and tried and tested ways of fixing broken and age-damaged organs in the body.
To add to the list of strategies, I noticed an article today on a possible middle path between old-style donor transplants (immunosuppressant drugs and all) and the near future of organs that are populated by the patient's own stem cells. It may be possible to use the knowledge acquired by stem cell researchers to date in order to minimize or completely remove the risk of immune rejection of a donor organ:
In a standard kidney transplant, the donor agrees to donate their kidney. In the approach being studied, the individual is asked to donate part of their immune system as well. The process begins about one month before the kidney transplant, when bone marrow stem cells are collected from the blood of the kidney donor using a process called apheresis. The donor cells are then sent to the University of Louisville to be processed, where researchers enrich for "facilitating cells" believed to help transplants succeed. During the same time period, the recipient undergoes pre-transplant "conditioning," which includes radiation and chemotherapy to suppress the bone marrow so the donor's stem cells have more space to grow in the recipient's body.
Once the facilitating cell-enriched stem cell product has been prepared, it is transported back to Northwestern, where the recipient undergoes a kidney transplant. The donor stem cells are then transplanted one day later and prompt stem cells to form in the marrow from which other specialized blood cells, like immune cells, develop. The goal is to create an environment where two bone marrow systems exist and function in one person. Following transplantation, the recipient takes anti-rejection drugs which are decreased over time with the goal to stop a year after the transplant.
Less than two years after her successful kidney transplant, 47-year-old mother and actress Lindsay Porter of Chicago, is living a life that most transplant recipients dream of - she is currently free of anti-rejection medications and says at times, she has to remind herself that she had a kidney transplant. ... Doctors are hopeful that Porter will not need immunosuppressive drugs long-term, given her progress thus far.
You might look on this as creating a form of engineered chimerism. We know that some animals and humans exist with, for example, multiple blood types and genetically distinct systems in their body as a result of the fusion of two zygotes in the womb. These individuals don't seem to suffer any great harm from being chimeric, which might be taken as a promising sign for the long-term prospects of this form of stem cell medicine.