For the first time in medical history, scientists have transplanted a fully functioning lab-grown organ into a living animal. Doctors at Massachusetts General Hospital accomplished the tasks using a donor rat’s kidneys and stem cells, along with a lot of sweat and toil. The bioengineered kidneys were successfully transplanted into the lucky rat, and the organs were fully accepted and even began produced urine again.
While we’ve seemingly been growing stem-cell organs forever now, this is the first time scientists have been able to not just grow a replica of an organ but a fully functioning version that was accepted and used by a living individual. This leap is comparable to the difference between making a plastic model of an airplane and making an airplane that can fly. In other words, the difference between an approximation and the real thing.
To accomplish this feat, the doctors at Mass. General took a rat’s kidney and stripped it down to a collagen scaffold (the image above) by using a detergent strips cells away. The team then seeded the scaffold with two types of stem cells and loaded the constructs into a whole-organ bioreactor (which is my new heavy metal band name). The stem cells were able to successfully grow and mature into a fully functioning kidney again – albeit with a diminished ability to produce urine. When transplanted back into the donor rat 5 days later, the organs were fully accepted by the animal’s immune system and continued to make this rudimentary urine.
Currently there are 100,000 individuals in the United States waiting for a kidney transplant, and 400,000 individuals living with end-stage kidney disease requiring hemodialysis. “If this technology can be scaled to human-sized grafts, patients suffering from renal failure who are currently waiting for donor kidneys or who are not transplant candidates could theoretically receive new organs derived from their own cells” says Harald Ott, MD, PhD, of the Mass. General Center for Regenerative Medicine. The team is now looking into pig and human organs for a similar process.