Both laymen and surgeons have become faint-hearted about heart transplants.… The rejection and infection problems remain unsolved, and although Dr. [Denton A.] Cooley has performed the greatest number of transplants in the world, he has had to stop operating for lack of donors. — Science News, March 15, 1969
Candidates for heart or other organ transplants still far outnumber donors. Every day, 20 people on average die while waiting for a transplant in the United States. Scientists hope to remedy the shortage using organs harvested from animals. To keep a human body from rejecting nonhuman cells, scientists are turning to gene editing (SN: 10/14/17, p. 26). So far, baboons given genetically modified pig hearts have survived for about six months (SN Online: 12/5/18). Others are growing organs, creating a sterilized scaffold from an animal or cadaver organ and repopulating the scaffold with the organ recipient’s cells (SN: 5/18/13, p. 14). Pigs have survived several weeks after being implanted with lab-grown lungs (SN: 9/15/18, p. 8).